Clean up formatting of this file.

The file should now follow PEP 7, except that it uses 4 space indents
(in the style of Py3k).  This particular code would be really hard to
read with the regular tab idents.

Other changes:
 - reflow long lines
 - change multi-line conditionals to have test at end of line

1 files changed, 2048 insertions, 2029 deletions

diff --git a/Python/ast.c b/Python/ast.c
index 6131ca5..eb4c68b 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -25,7 +25,8 @@ static asdl_seq *seq_for_testlist(struct compiling *, const node *);
 static expr_ty ast_for_expr(struct compiling *, const node *);
 static stmt_ty ast_for_stmt(struct compiling *, const node *);
 static asdl_seq *ast_for_suite(struct compiling *, const node *);
-static asdl_seq *ast_for_exprlist(struct compiling *, const node *, expr_context_ty);
+static asdl_seq *ast_for_exprlist(struct compiling *, const node *,
+                                  expr_context_ty);
 static expr_ty ast_for_testlist(struct compiling *, const node *);
 static expr_ty ast_for_testlist_gexp(struct compiling *, const node *);
 
@@ -37,7 +38,7 @@ static PyObject *parsestr(const char *s, const char *encoding);
 static PyObject *parsestrplus(struct compiling *, const node *n);
 
 #ifndef LINENO
-#define LINENO(n)	((n)->n_lineno)
+#define LINENO(n)       ((n)->n_lineno)
 #endif
 
 static identifier
@@ -62,7 +63,7 @@ ast_error(const node *n, const char *errstr)
 {
     PyObject *u = Py_BuildValue("zi", errstr, LINENO(n));
     if (!u)
-	return 0;
+        return 0;
     PyErr_SetObject(PyExc_SyntaxError, u);
     Py_DECREF(u);
     return 0;
@@ -76,36 +77,36 @@ ast_error_finish(const char *filename)
 
     assert(PyErr_Occurred());
     if (!PyErr_ExceptionMatches(PyExc_SyntaxError))
-	return;
+        return;
 
     PyErr_Fetch(&type, &value, &tback);
     errstr = PyTuple_GetItem(value, 0);
     if (!errstr)
-	return;
+        return;
     Py_INCREF(errstr);
     lineno = PyInt_AsLong(PyTuple_GetItem(value, 1));
     if (lineno == -1) {
-	Py_DECREF(errstr);
-	return;
+        Py_DECREF(errstr);
+        return;
     }
     Py_DECREF(value);
 
     loc = PyErr_ProgramText(filename, lineno);
     if (!loc) {
-	Py_INCREF(Py_None);
-	loc = Py_None;
+        Py_INCREF(Py_None);
+        loc = Py_None;
     }
     tmp = Py_BuildValue("(zlOO)", filename, lineno, Py_None, loc);
     Py_DECREF(loc);
     if (!tmp) {
-	Py_DECREF(errstr);
-	return;
+        Py_DECREF(errstr);
+        return;
     }
     value = PyTuple_Pack(2, errstr, tmp);
     Py_DECREF(errstr);
     Py_DECREF(tmp);
     if (!value)
-	return;
+        return;
     PyErr_Restore(type, value, tback);
 }
 
@@ -130,41 +131,41 @@ num_stmts(const node *n)
     node *ch;
 
     switch (TYPE(n)) {
-	case single_input:
-	    if (TYPE(CHILD(n, 0)) == NEWLINE)
-		return 0;
-	    else
-		return num_stmts(CHILD(n, 0));
-	case file_input:
-	    l = 0;
-	    for (i = 0; i < NCH(n); i++) {
-		ch = CHILD(n, i);
-		if (TYPE(ch) == stmt)
-		    l += num_stmts(ch);
-	    }
-	    return l;
-	case stmt:
-	    return num_stmts(CHILD(n, 0));
-	case compound_stmt:
-	    return 1;
-	case simple_stmt:
-	    return NCH(n) / 2; /* Divide by 2 to remove count of semi-colons */
-	case suite:
-	    if (NCH(n) == 1)
-		return num_stmts(CHILD(n, 0));
-	    else {
-		l = 0;
-		for (i = 2; i < (NCH(n) - 1); i++)
-		    l += num_stmts(CHILD(n, i));
-		return l;
-	    }
-	default: {
-	    char buf[128];
-
-	    sprintf(buf, "Non-statement found: %d %d\n",
-		    TYPE(n), NCH(n));
-	    Py_FatalError(buf);
-	}
+        case single_input:
+            if (TYPE(CHILD(n, 0)) == NEWLINE)
+                return 0;
+            else
+                return num_stmts(CHILD(n, 0));
+        case file_input:
+            l = 0;
+            for (i = 0; i < NCH(n); i++) {
+                ch = CHILD(n, i);
+                if (TYPE(ch) == stmt)
+                    l += num_stmts(ch);
+            }
+            return l;
+        case stmt:
+            return num_stmts(CHILD(n, 0));
+        case compound_stmt:
+            return 1;
+        case simple_stmt:
+            return NCH(n) / 2; /* Divide by 2 to remove count of semi-colons */
+        case suite:
+            if (NCH(n) == 1)
+                return num_stmts(CHILD(n, 0));
+            else {
+                l = 0;
+                for (i = 2; i < (NCH(n) - 1); i++)
+                    l += num_stmts(CHILD(n, i));
+                return l;
+            }
+        default: {
+            char buf[128];
+
+            sprintf(buf, "Non-statement found: %d %d\n",
+                    TYPE(n), NCH(n));
+            Py_FatalError(buf);
+        }
     }
     assert(0);
     return 0;
@@ -175,7 +176,7 @@ num_stmts(const node *n)
 
 mod_ty
 PyAST_FromNode(const node *n, PyCompilerFlags *flags, const char *filename,
-	       PyArena *arena)
+               PyArena *arena)
 {
     int i, j, k, num;
     asdl_seq *stmts = NULL;
@@ -184,96 +185,96 @@ PyAST_FromNode(const node *n, PyCompilerFlags *flags, const char *filename,
     struct compiling c;
 
     if (flags && flags->cf_flags & PyCF_SOURCE_IS_UTF8) {
-	c.c_encoding = "utf-8";
-	if (TYPE(n) == encoding_decl) {
-		ast_error(n, "encoding declaration in Unicode string");
-		goto error;
-	}
+        c.c_encoding = "utf-8";
+        if (TYPE(n) == encoding_decl) {
+            ast_error(n, "encoding declaration in Unicode string");
+            goto error;
+        }
     } else if (TYPE(n) == encoding_decl) {
-	c.c_encoding = STR(n);
-	n = CHILD(n, 0);
+        c.c_encoding = STR(n);
+        n = CHILD(n, 0);
     } else {
-	c.c_encoding = NULL;
+        c.c_encoding = NULL;
     }
     c.c_arena = arena;
 
     k = 0;
     switch (TYPE(n)) {
-	case file_input:
-	    stmts = asdl_seq_new(num_stmts(n), arena);
-	    if (!stmts)
-		    return NULL;
-	    for (i = 0; i < NCH(n) - 1; i++) {
-		ch = CHILD(n, i);
-		if (TYPE(ch) == NEWLINE)
-		    continue;
-		REQ(ch, stmt);
-		num = num_stmts(ch);
-		if (num == 1) {
-		    s = ast_for_stmt(&c, ch);
-		    if (!s)
-			goto error;
-		    asdl_seq_SET(stmts, k++, s);
-		}
-		else {
-		    ch = CHILD(ch, 0);
-		    REQ(ch, simple_stmt);
-		    for (j = 0; j < num; j++) {
-			s = ast_for_stmt(&c, CHILD(ch, j * 2));
-			if (!s)
-			    goto error;
-			asdl_seq_SET(stmts, k++, s);
-		    }
-		}
-	    }
-	    return Module(stmts, arena);
-	case eval_input: {
-	    expr_ty testlist_ast;
-
-	    /* XXX Why not gen_for here? */
-	    testlist_ast = ast_for_testlist(&c, CHILD(n, 0));
-	    if (!testlist_ast)
-		goto error;
-	    return Expression(testlist_ast, arena);
-	}
-	case single_input:
-	    if (TYPE(CHILD(n, 0)) == NEWLINE) {
-		stmts = asdl_seq_new(1, arena);
-		if (!stmts)
-		    goto error;
-		asdl_seq_SET(stmts, 0, Pass(n->n_lineno, n->n_col_offset,
-					    arena));
-		return Interactive(stmts, arena);
-	    }
-	    else {
-		n = CHILD(n, 0);
-		num = num_stmts(n);
-		stmts = asdl_seq_new(num, arena);
-		if (!stmts)
-		    goto error;
-		if (num == 1) {
-		    s = ast_for_stmt(&c, n);
-		    if (!s)
-			goto error;
-		    asdl_seq_SET(stmts, 0, s);
-		}
-		else {
-		    /* Only a simple_stmt can contain multiple statements. */
-		    REQ(n, simple_stmt);
-		    for (i = 0; i < NCH(n); i += 2) {
-			if (TYPE(CHILD(n, i)) == NEWLINE)
-			    break;
-			s = ast_for_stmt(&c, CHILD(n, i));
-			if (!s)
-			    goto error;
-			asdl_seq_SET(stmts, i / 2, s);
-		    }
-		}
-
-		return Interactive(stmts, arena);
-	    }
-	default:
-	    goto error;
+        case file_input:
+            stmts = asdl_seq_new(num_stmts(n), arena);
+            if (!stmts)
+                return NULL;
+            for (i = 0; i < NCH(n) - 1; i++) {
+                ch = CHILD(n, i);
+                if (TYPE(ch) == NEWLINE)
+                    continue;
+                REQ(ch, stmt);
+                num = num_stmts(ch);
+                if (num == 1) {
+                    s = ast_for_stmt(&c, ch);
+                    if (!s)
+                        goto error;
+                    asdl_seq_SET(stmts, k++, s);
+                }
+                else {
+                    ch = CHILD(ch, 0);
+                    REQ(ch, simple_stmt);
+                    for (j = 0; j < num; j++) {
+                        s = ast_for_stmt(&c, CHILD(ch, j * 2));
+                        if (!s)
+                            goto error;
+                        asdl_seq_SET(stmts, k++, s);
+                    }
+                }
+            }
+            return Module(stmts, arena);
+        case eval_input: {
+            expr_ty testlist_ast;
+
+            /* XXX Why not gen_for here? */
+            testlist_ast = ast_for_testlist(&c, CHILD(n, 0));
+            if (!testlist_ast)
+                goto error;
+            return Expression(testlist_ast, arena);
+        }
+        case single_input:
+            if (TYPE(CHILD(n, 0)) == NEWLINE) {
+                stmts = asdl_seq_new(1, arena);
+                if (!stmts)
+                    goto error;
+                asdl_seq_SET(stmts, 0, Pass(n->n_lineno, n->n_col_offset,
+                                            arena));
+                return Interactive(stmts, arena);
+            }
+            else {
+                n = CHILD(n, 0);
+                num = num_stmts(n);
+                stmts = asdl_seq_new(num, arena);
+                if (!stmts)
+                    goto error;
+                if (num == 1) {
+                    s = ast_for_stmt(&c, n);
+                    if (!s)
+                        goto error;
+                    asdl_seq_SET(stmts, 0, s);
+                }
+                else {
+                    /* Only a simple_stmt can contain multiple statements. */
+                    REQ(n, simple_stmt);
+                    for (i = 0; i < NCH(n); i += 2) {
+                        if (TYPE(CHILD(n, i)) == NEWLINE)
+                            break;
+                        s = ast_for_stmt(&c, CHILD(n, i));
+                        if (!s)
+                            goto error;
+                        asdl_seq_SET(stmts, i / 2, s);
+                    }
+                }
+
+                return Interactive(stmts, arena);
+            }
+        default:
+            goto error;
     }
  error:
     ast_error_finish(filename);
@@ -287,30 +288,30 @@ static operator_ty
 get_operator(const node *n)
 {
     switch (TYPE(n)) {
-	case VBAR:
-	    return BitOr;
-	case CIRCUMFLEX:
-	    return BitXor;
-	case AMPER:
-	    return BitAnd;
-	case LEFTSHIFT:
-	    return LShift;
-	case RIGHTSHIFT:
-	    return RShift;
-	case PLUS:
-	    return Add;
-	case MINUS:
-	    return Sub;
-	case STAR:
-	    return Mult;
-	case SLASH:
-	    return Div;
-	case DOUBLESLASH:
-	    return FloorDiv;
-	case PERCENT:
-	    return Mod;
-	default:
-	    return (operator_ty)0;
+        case VBAR:
+            return BitOr;
+        case CIRCUMFLEX:
+            return BitXor;
+        case AMPER:
+            return BitAnd;
+        case LEFTSHIFT:
+            return LShift;
+        case RIGHTSHIFT:
+            return RShift;
+        case PLUS:
+            return Add;
+        case MINUS:
+            return Sub;
+        case STAR:
+            return Mult;
+        case SLASH:
+            return Div;
+        case DOUBLESLASH:
+            return FloorDiv;
+        case PERCENT:
+            return Mod;
+        default:
+            return (operator_ty)0;
     }
 }
 
@@ -340,93 +341,93 @@ set_context(expr_ty e, expr_context_ty ctx, const node *n)
     assert(ctx != AugStore && ctx != AugLoad);
 
     switch (e->kind) {
-	case Attribute_kind:
-	    if (ctx == Store &&
-		    !strcmp(PyString_AS_STRING(e->v.Attribute.attr), "None")) {
-		    return ast_error(n, "assignment to None");
-	    }
-	    e->v.Attribute.ctx = ctx;
-	    break;
-	case Subscript_kind:
-	    e->v.Subscript.ctx = ctx;
-	    break;
-	case Name_kind:
-	    if (ctx == Store &&
-		!strcmp(PyString_AS_STRING(e->v.Name.id), "None")) {
-		    return ast_error(n, "assignment to None");
-	    }
-	    e->v.Name.ctx = ctx;
-	    break;
-	case List_kind:
-	    e->v.List.ctx = ctx;
-	    s = e->v.List.elts;
-	    break;
-	case Tuple_kind:
-	    if (asdl_seq_LEN(e->v.Tuple.elts) == 0) 
-		return ast_error(n, "can't assign to ()");
-	    e->v.Tuple.ctx = ctx;
-	    s = e->v.Tuple.elts;
-	    break;
-	case Lambda_kind:
-	    expr_name = "lambda";
-	    break;
-	case Call_kind:
-	    expr_name = "function call";
-	    break;
-	case BoolOp_kind:
-	case BinOp_kind:
-	case UnaryOp_kind:
-	    expr_name = "operator";
-	    break;
-	case GeneratorExp_kind:
-	    expr_name = "generator expression";
-	    break;
-	case Yield_kind:
-	    expr_name = "yield expression";
-	    break;
-	case ListComp_kind:
-	    expr_name = "list comprehension";
-	    break;
-	case Dict_kind:
-	case Num_kind:
-	case Str_kind:
-	    expr_name = "literal";
-	    break;
-	case Compare_kind:
-	    expr_name = "comparison";
-	    break;
-	case Repr_kind:
-	    expr_name = "repr";
-	    break;
-	case IfExp_kind:
-	    expr_name = "conditional expression";
-	    break;
-	default:
-	    PyErr_Format(PyExc_SystemError, 
-			 "unexpected expression in assignment %d (line %d)", 
-			 e->kind, e->lineno);
-	    return 0;
+        case Attribute_kind:
+            if (ctx == Store &&
+                !strcmp(PyString_AS_STRING(e->v.Attribute.attr), "None")) {
+                return ast_error(n, "assignment to None");
+            }
+            e->v.Attribute.ctx = ctx;
+            break;
+        case Subscript_kind:
+            e->v.Subscript.ctx = ctx;
+            break;
+        case Name_kind:
+            if (ctx == Store &&
+                !strcmp(PyString_AS_STRING(e->v.Name.id), "None")) {
+                    return ast_error(n, "assignment to None");
+            }
+            e->v.Name.ctx = ctx;
+            break;
+        case List_kind:
+            e->v.List.ctx = ctx;
+            s = e->v.List.elts;
+            break;
+        case Tuple_kind:
+            if (asdl_seq_LEN(e->v.Tuple.elts) == 0) 
+                return ast_error(n, "can't assign to ()");
+            e->v.Tuple.ctx = ctx;
+            s = e->v.Tuple.elts;
+            break;
+        case Lambda_kind:
+            expr_name = "lambda";
+            break;
+        case Call_kind:
+            expr_name = "function call";
+            break;
+        case BoolOp_kind:
+        case BinOp_kind:
+        case UnaryOp_kind:
+            expr_name = "operator";
+            break;
+        case GeneratorExp_kind:
+            expr_name = "generator expression";
+            break;
+        case Yield_kind:
+            expr_name = "yield expression";
+            break;
+        case ListComp_kind:
+            expr_name = "list comprehension";
+            break;
+        case Dict_kind:
+        case Num_kind:
+        case Str_kind:
+            expr_name = "literal";
+            break;
+        case Compare_kind:
+            expr_name = "comparison";
+            break;
+        case Repr_kind:
+            expr_name = "repr";
+            break;
+        case IfExp_kind:
+            expr_name = "conditional expression";
+            break;
+        default:
+            PyErr_Format(PyExc_SystemError, 
+                         "unexpected expression in assignment %d (line %d)", 
+                         e->kind, e->lineno);
+            return 0;
     }
     /* Check for error string set by switch */
     if (expr_name) {
-	char buf[300];
-	PyOS_snprintf(buf, sizeof(buf),
-		      "can't %s %s",
-		      ctx == Store ? "assign to" : "delete",
-		      expr_name);
-	return ast_error(n, buf);
+        char buf[300];
+        PyOS_snprintf(buf, sizeof(buf),
+                      "can't %s %s",
+                      ctx == Store ? "assign to" : "delete",
+                      expr_name);
+        return ast_error(n, buf);
     }
 
     /* If the LHS is a list or tuple, we need to set the assignment
-       context for all the contained elements.	
+       context for all the contained elements.  
     */
     if (s) {
-	int i;
+        int i;
 
-	for (i = 0; i < asdl_seq_LEN(s); i++) {
-	    if (!set_context((expr_ty)asdl_seq_GET(s, i), ctx, n))
-		return 0;
-	}
+        for (i = 0; i < asdl_seq_LEN(s); i++) {
+            if (!set_context((expr_ty)asdl_seq_GET(s, i), ctx, n))
+                return 0;
+        }
     }
     return 1;
 }
@@ -437,35 +438,35 @@ ast_for_augassign(const node *n)
     REQ(n, augassign);
     n = CHILD(n, 0);
     switch (STR(n)[0]) {
-	case '+':
-	    return Add;
-	case '-':
-	    return Sub;
-	case '/':
-	    if (STR(n)[1] == '/')
-		return FloorDiv;
-	    else
-		return Div;
-	case '%':
-	    return Mod;
-	case '<':
-	    return LShift;
-	case '>':
-	    return RShift;
-	case '&':
-	    return BitAnd;
-	case '^':
-	    return BitXor;
-	case '|':
-	    return BitOr;
-	case '*':
-	    if (STR(n)[1] == '*')
-		return Pow;
-	    else
-		return Mult;
-	default:
-	    PyErr_Format(PyExc_SystemError, "invalid augassign: %s", STR(n));
-	    return (operator_ty)0;
+        case '+':
+            return Add;
+        case '-':
+            return Sub;
+        case '/':
+            if (STR(n)[1] == '/')
+                return FloorDiv;
+            else
+                return Div;
+        case '%':
+            return Mod;
+        case '<':
+            return LShift;
+        case '>':
+            return RShift;
+        case '&':
+            return BitAnd;
+        case '^':
+            return BitXor;
+        case '|':
+            return BitOr;
+        case '*':
+            if (STR(n)[1] == '*')
+                return Pow;
+            else
+                return Mult;
+        default:
+            PyErr_Format(PyExc_SystemError, "invalid augassign: %s", STR(n));
+            return (operator_ty)0;
     }
 }
 
@@ -473,51 +474,51 @@ static cmpop_ty
 ast_for_comp_op(const node *n)
 {
     /* comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'
-	       |'is' 'not'
+               |'is' 'not'
     */
     REQ(n, comp_op);
     if (NCH(n) == 1) {
-	n = CHILD(n, 0);
-	switch (TYPE(n)) {
-	    case LESS:
-		return Lt;
-	    case GREATER:
-		return Gt;
-	    case EQEQUAL:			/* == */
-		return Eq;
-	    case LESSEQUAL:
-		return LtE;
-	    case GREATEREQUAL:
-		return GtE;
-	    case NOTEQUAL:
-		return NotEq;
-	    case NAME:
-		if (strcmp(STR(n), "in") == 0)
-		    return In;
-		if (strcmp(STR(n), "is") == 0)
-		    return Is;
-	    default:
-		PyErr_Format(PyExc_SystemError, "invalid comp_op: %s",
-			     STR(n));
-		return (cmpop_ty)0;
-	}
+        n = CHILD(n, 0);
+        switch (TYPE(n)) {
+            case LESS:
+                return Lt;
+            case GREATER:
+                return Gt;
+            case EQEQUAL:                       /* == */
+                return Eq;
+            case LESSEQUAL:
+                return LtE;
+            case GREATEREQUAL:
+                return GtE;
+            case NOTEQUAL:
+                return NotEq;
+            case NAME:
+                if (strcmp(STR(n), "in") == 0)
+                    return In;
+                if (strcmp(STR(n), "is") == 0)
+                    return Is;
+            default:
+                PyErr_Format(PyExc_SystemError, "invalid comp_op: %s",
+                             STR(n));
+                return (cmpop_ty)0;
+        }
     }
     else if (NCH(n) == 2) {
-	/* handle "not in" and "is not" */
-	switch (TYPE(CHILD(n, 0))) {
-	    case NAME:
-		if (strcmp(STR(CHILD(n, 1)), "in") == 0)
-		    return NotIn;
-		if (strcmp(STR(CHILD(n, 0)), "is") == 0)
-		    return IsNot;
-	    default:
-		PyErr_Format(PyExc_SystemError, "invalid comp_op: %s %s",
-			     STR(CHILD(n, 0)), STR(CHILD(n, 1)));
-		return (cmpop_ty)0;
-	}
+        /* handle "not in" and "is not" */
+        switch (TYPE(CHILD(n, 0))) {
+            case NAME:
+                if (strcmp(STR(CHILD(n, 1)), "in") == 0)
+                    return NotIn;
+                if (strcmp(STR(CHILD(n, 0)), "is") == 0)
+                    return IsNot;
+            default:
+                PyErr_Format(PyExc_SystemError, "invalid comp_op: %s %s",
+                             STR(CHILD(n, 0)), STR(CHILD(n, 1)));
+                return (cmpop_ty)0;
+        }
     }
     PyErr_Format(PyExc_SystemError, "invalid comp_op: has %d children",
-		 NCH(n));
+                 NCH(n));
     return (cmpop_ty)0;
 }
 
@@ -528,26 +529,25 @@ seq_for_testlist(struct compiling *c, const node *n)
     asdl_seq *seq;
     expr_ty expression;
     int i;
-    assert(TYPE(n) == testlist
-	   || TYPE(n) == listmaker
-	   || TYPE(n) == testlist_gexp
-	   || TYPE(n) == testlist_safe
-	   || TYPE(n) == testlist1
-	   );
+    assert(TYPE(n) == testlist ||
+           TYPE(n) == listmaker ||
+           TYPE(n) == testlist_gexp ||
+           TYPE(n) == testlist_safe ||
+           TYPE(n) == testlist1);
 
     seq = asdl_seq_new((NCH(n) + 1) / 2, c->c_arena);
     if (!seq)
-	return NULL;
+        return NULL;
 
     for (i = 0; i < NCH(n); i += 2) {
-	assert(TYPE(CHILD(n, i)) == test || TYPE(CHILD(n, i)) == old_test);
+        assert(TYPE(CHILD(n, i)) == test || TYPE(CHILD(n, i)) == old_test);
 
-	expression = ast_for_expr(c, CHILD(n, i));
-	if (!expression)
-	    return NULL;
+        expression = ast_for_expr(c, CHILD(n, i));
+        if (!expression)
+            return NULL;
 
-	assert(i / 2 < seq->size);
-	asdl_seq_SET(seq, i / 2, expression);
+        assert(i / 2 < seq->size);
+        asdl_seq_SET(seq, i / 2, expression);
     }
     return seq;
 }
@@ -559,46 +559,46 @@ compiler_complex_args(struct compiling *c, const node *n)
     expr_ty result;
     asdl_seq *args = asdl_seq_new(len, c->c_arena);
     if (!args)
-	return NULL;
+        return NULL;
 
     /* fpdef: NAME | '(' fplist ')'
        fplist: fpdef (',' fpdef)* [',']
     */
     REQ(n, fplist);
     for (i = 0; i < len; i++) {
-	const node *fpdef_node = CHILD(n, 2*i);
-	const node *child;
-	expr_ty arg;
+        const node *fpdef_node = CHILD(n, 2*i);
+        const node *child;
+        expr_ty arg;
 set_name:
-	/* fpdef_node is either a NAME or an fplist */
-	child = CHILD(fpdef_node, 0);
-	if (TYPE(child) == NAME) {
-		if (!strcmp(STR(child), "None")) {
-			ast_error(child, "assignment to None");
-			return NULL;
-		    }	
-	    arg = Name(NEW_IDENTIFIER(child), Store, LINENO(child),
-		       child->n_col_offset, c->c_arena);
-	    }
-	else {
-	    assert(TYPE(fpdef_node) == fpdef);
-	    /* fpdef_node[0] is not a name, so it must be a '(', get CHILD[1] */
-	    child = CHILD(fpdef_node, 1);
-	    assert(TYPE(child) == fplist);
-	    /* NCH == 1 means we have (x), we need to elide the extra parens */
-	    if (NCH(child) == 1) {
-		fpdef_node = CHILD(child, 0);
-		assert(TYPE(fpdef_node) == fpdef);
-		goto set_name;
-	    }
-	    arg = compiler_complex_args(c, child);
-	}
-	asdl_seq_SET(args, i, arg);
+        /* fpdef_node is either a NAME or an fplist */
+        child = CHILD(fpdef_node, 0);
+        if (TYPE(child) == NAME) {
+            if (!strcmp(STR(child), "None")) {
+                ast_error(child, "assignment to None");
+                return NULL;
+            }   
+            arg = Name(NEW_IDENTIFIER(child), Store, LINENO(child),
+                       child->n_col_offset, c->c_arena);
+        }
+        else {
+            assert(TYPE(fpdef_node) == fpdef);
+            /* fpdef_node[0] is not a name, so it must be '(', get CHILD[1] */
+            child = CHILD(fpdef_node, 1);
+            assert(TYPE(child) == fplist);
+            /* NCH == 1 means we have (x), we need to elide the extra parens */
+            if (NCH(child) == 1) {
+                fpdef_node = CHILD(child, 0);
+                assert(TYPE(fpdef_node) == fpdef);
+                goto set_name;
+            }
+            arg = compiler_complex_args(c, child);
+        }
+        asdl_seq_SET(args, i, arg);
     }
 
     result = Tuple(args, Store, LINENO(n), n->n_col_offset, c->c_arena);
     if (!set_context(result, Store, n))
-	return NULL;
+        return NULL;
     return result;
 }
 
@@ -610,7 +610,7 @@ ast_for_arguments(struct compiling *c, const node *n)
 {
     /* parameters: '(' [varargslist] ')'
        varargslist: (fpdef ['=' test] ',')* ('*' NAME [',' '**' NAME]
-	    | '**' NAME) | fpdef ['=' test] (',' fpdef ['=' test])* [',']
+            | '**' NAME) | fpdef ['=' test] (',' fpdef ['=' test])* [',']
     */
     int i, j, k, n_args = 0, n_defaults = 0, found_default = 0;
     asdl_seq *args, *defaults;
@@ -618,26 +618,26 @@ ast_for_arguments(struct compiling *c, const node *n)
     node *ch;
 
     if (TYPE(n) == parameters) {
-	if (NCH(n) == 2) /* () as argument list */
-	    return arguments(NULL, NULL, NULL, NULL, c->c_arena);
-	n = CHILD(n, 1);
+        if (NCH(n) == 2) /* () as argument list */
+            return arguments(NULL, NULL, NULL, NULL, c->c_arena);
+        n = CHILD(n, 1);
     }
     REQ(n, varargslist);
 
     /* first count the number of normal args & defaults */
     for (i = 0; i < NCH(n); i++) {
-	ch = CHILD(n, i);
-	if (TYPE(ch) == fpdef)
-	    n_args++;
-	if (TYPE(ch) == EQUAL)
-	    n_defaults++;
+        ch = CHILD(n, i);
+        if (TYPE(ch) == fpdef)
+            n_args++;
+        if (TYPE(ch) == EQUAL)
+            n_defaults++;
     }
     args = (n_args ? asdl_seq_new(n_args, c->c_arena) : NULL);
     if (!args && n_args)
-	return NULL; /* Don't need to goto error; no objects allocated */
+        return NULL; /* Don't need to goto error; no objects allocated */
     defaults = (n_defaults ? asdl_seq_new(n_defaults, c->c_arena) : NULL);
     if (!defaults && n_defaults)
-	return NULL; /* Don't need to goto error; no objects allocated */
+        return NULL; /* Don't need to goto error; no objects allocated */
 
     /* fpdef: NAME | '(' fplist ')'
        fplist: fpdef (',' fpdef)* [',']
@@ -646,80 +646,80 @@ ast_for_arguments(struct compiling *c, const node *n)
     j = 0;  /* index for defaults */
     k = 0;  /* index for args */
     while (i < NCH(n)) {
-	ch = CHILD(n, i);
-	switch (TYPE(ch)) {
-	    case fpdef:
-	    handle_fpdef:
-		/* XXX Need to worry about checking if TYPE(CHILD(n, i+1)) is
-		   anything other than EQUAL or a comma? */
-		/* XXX Should NCH(n) check be made a separate check? */
-		if (i + 1 < NCH(n) && TYPE(CHILD(n, i + 1)) == EQUAL) {
-		    expr_ty expression = ast_for_expr(c, CHILD(n, i + 2));
-		    if (!expression)
-			    goto error;
-		    assert(defaults != NULL);
-		    asdl_seq_SET(defaults, j++, expression);
-		    i += 2;
-		    found_default = 1;
-		}
-		else if (found_default) {
-		    ast_error(n, 
-			     "non-default argument follows default argument");
-		    goto error;
-		}
-		if (NCH(ch) == 3) {
-		    ch = CHILD(ch, 1);
-		    /* def foo((x)): is not complex, special case. */
-		    if (NCH(ch) != 1) {
-			/* We have complex arguments, setup for unpacking. */
-			asdl_seq_SET(args, k++, compiler_complex_args(c, ch));
-		    } else {
-			/* def foo((x)): setup for checking NAME below. */
-			/* Loop because there can be many parens and tuple
-			   unpacking mixed in. */
-			ch = CHILD(ch, 0);
-			assert(TYPE(ch) == fpdef);
-			goto handle_fpdef;
-		    }
-		}
-		if (TYPE(CHILD(ch, 0)) == NAME) {
-		    expr_ty name;
-		    if (!strcmp(STR(CHILD(ch, 0)), "None")) {
-			    ast_error(CHILD(ch, 0), "assignment to None");
-			    goto error;
-		    }
-		    name = Name(NEW_IDENTIFIER(CHILD(ch, 0)),
-				Param, LINENO(ch), ch->n_col_offset,
-				c->c_arena);
-		    if (!name)
-			goto error;
-		    asdl_seq_SET(args, k++, name);
-					 
-		}
-		i += 2; /* the name and the comma */
-		break;
-	    case STAR:
-		if (!strcmp(STR(CHILD(n, i+1)), "None")) {
-			ast_error(CHILD(n, i+1), "assignment to None");
-			goto error;
-		}
-		vararg = NEW_IDENTIFIER(CHILD(n, i+1));
-		i += 3;
-		break;
-	    case DOUBLESTAR:
-		if (!strcmp(STR(CHILD(n, i+1)), "None")) {
-			ast_error(CHILD(n, i+1), "assignment to None");
-			goto error;
-		}
-		kwarg = NEW_IDENTIFIER(CHILD(n, i+1));
-		i += 3;
-		break;
-	    default:
-		PyErr_Format(PyExc_SystemError,
-			     "unexpected node in varargslist: %d @ %d",
-			     TYPE(ch), i);
-		goto error;
-	}
+        ch = CHILD(n, i);
+        switch (TYPE(ch)) {
+            case fpdef:
+            handle_fpdef:
+                /* XXX Need to worry about checking if TYPE(CHILD(n, i+1)) is
+                   anything other than EQUAL or a comma? */
+                /* XXX Should NCH(n) check be made a separate check? */
+                if (i + 1 < NCH(n) && TYPE(CHILD(n, i + 1)) == EQUAL) {
+                    expr_ty expression = ast_for_expr(c, CHILD(n, i + 2));
+                    if (!expression)
+                        goto error;
+                    assert(defaults != NULL);
+                    asdl_seq_SET(defaults, j++, expression);
+                    i += 2;
+                    found_default = 1;
+                }
+                else if (found_default) {
+                    ast_error(n, 
+                             "non-default argument follows default argument");
+                    goto error;
+                }
+                if (NCH(ch) == 3) {
+                    ch = CHILD(ch, 1);
+                    /* def foo((x)): is not complex, special case. */
+                    if (NCH(ch) != 1) {
+                        /* We have complex arguments, setup for unpacking. */
+                        asdl_seq_SET(args, k++, compiler_complex_args(c, ch));
+                    } else {
+                        /* def foo((x)): setup for checking NAME below. */
+                        /* Loop because there can be many parens and tuple
+                           unpacking mixed in. */
+                        ch = CHILD(ch, 0);
+                        assert(TYPE(ch) == fpdef);
+                        goto handle_fpdef;
+                    }
+                }
+                if (TYPE(CHILD(ch, 0)) == NAME) {
+                    expr_ty name;
+                    if (!strcmp(STR(CHILD(ch, 0)), "None")) {
+                        ast_error(CHILD(ch, 0), "assignment to None");
+                        goto error;
+                    }
+                    name = Name(NEW_IDENTIFIER(CHILD(ch, 0)),
+                                Param, LINENO(ch), ch->n_col_offset,
+                                c->c_arena);
+                    if (!name)
+                        goto error;
+                    asdl_seq_SET(args, k++, name);
+                                         
+                }
+                i += 2; /* the name and the comma */
+                break;
+            case STAR:
+                if (!strcmp(STR(CHILD(n, i+1)), "None")) {
+                    ast_error(CHILD(n, i+1), "assignment to None");
+                    goto error;
+                }
+                vararg = NEW_IDENTIFIER(CHILD(n, i+1));
+                i += 3;
+                break;
+            case DOUBLESTAR:
+                if (!strcmp(STR(CHILD(n, i+1)), "None")) {
+                    ast_error(CHILD(n, i+1), "assignment to None");
+                    goto error;
+                }
+                kwarg = NEW_IDENTIFIER(CHILD(n, i+1));
+                i += 3;
+                break;
+            default:
+                PyErr_Format(PyExc_SystemError,
+                             "unexpected node in varargslist: %d @ %d",
+                             TYPE(ch), i);
+                goto error;
+        }
     }
 
     return arguments(args, vararg, kwarg, defaults, c->c_arena);
@@ -745,18 +745,18 @@ ast_for_dotted_name(struct compiling *c, const node *n)
 
     id = NEW_IDENTIFIER(CHILD(n, 0));
     if (!id)
-	return NULL;
+        return NULL;
     e = Name(id, Load, lineno, col_offset, c->c_arena);
     if (!e)
-	return NULL;
+        return NULL;
 
     for (i = 2; i < NCH(n); i+=2) {
-	id = NEW_IDENTIFIER(CHILD(n, i));
-	if (!id)
-	    return NULL;
-	e = Attribute(e, id, Load, lineno, col_offset, c->c_arena);
-	if (!e)
-	    return NULL;
+        id = NEW_IDENTIFIER(CHILD(n, i));
+        if (!id)
+            return NULL;
+        e = Attribute(e, id, Load, lineno, col_offset, c->c_arena);
+        if (!e)
+            return NULL;
     }
 
     return e;
@@ -775,24 +775,24 @@ ast_for_decorator(struct compiling *c, const node *n)
     
     name_expr = ast_for_dotted_name(c, CHILD(n, 1));
     if (!name_expr)
-	return NULL;
-	
+        return NULL;
+        
     if (NCH(n) == 3) { /* No arguments */
-	d = name_expr;
-	name_expr = NULL;
+        d = name_expr;
+        name_expr = NULL;
     }
     else if (NCH(n) == 5) { /* Call with no arguments */
-	d = Call(name_expr, NULL, NULL, NULL, NULL, LINENO(n),
-		 n->n_col_offset, c->c_arena);
-	if (!d)
-	    return NULL;
-	name_expr = NULL;
+        d = Call(name_expr, NULL, NULL, NULL, NULL, LINENO(n),
+                 n->n_col_offset, c->c_arena);
+        if (!d)
+            return NULL;
+        name_expr = NULL;
     }
     else {
-	d = ast_for_call(c, CHILD(n, 3), name_expr);
-	if (!d)
-	    return NULL;
-	name_expr = NULL;
+        d = ast_for_call(c, CHILD(n, 3), name_expr);
+        if (!d)
+            return NULL;
+        name_expr = NULL;
     }
 
     return d;
@@ -808,13 +808,13 @@ ast_for_decorators(struct compiling *c, const node *n)
     REQ(n, decorators);
     decorator_seq = asdl_seq_new(NCH(n), c->c_arena);
     if (!decorator_seq)
-	return NULL;
-	
+        return NULL;
+        
     for (i = 0; i < NCH(n); i++) {
-	d = ast_for_decorator(c, CHILD(n, i));
-	    if (!d)
-		return NULL;
-	    asdl_seq_SET(decorator_seq, i, d);
+        d = ast_for_decorator(c, CHILD(n, i));
+            if (!d)
+                return NULL;
+            asdl_seq_SET(decorator_seq, i, d);
     }
     return decorator_seq;
 }
@@ -832,31 +832,31 @@ ast_for_funcdef(struct compiling *c, const node *n)
     REQ(n, funcdef);
 
     if (NCH(n) == 6) { /* decorators are present */
-	decorator_seq = ast_for_decorators(c, CHILD(n, 0));
-	if (!decorator_seq)
-	    return NULL;
-	name_i = 2;
+        decorator_seq = ast_for_decorators(c, CHILD(n, 0));
+        if (!decorator_seq)
+            return NULL;
+        name_i = 2;
     }
     else {
-	name_i = 1;
+        name_i = 1;
     }
 
     name = NEW_IDENTIFIER(CHILD(n, name_i));
     if (!name)
-	return NULL;
+        return NULL;
     else if (!strcmp(STR(CHILD(n, name_i)), "None")) {
-	ast_error(CHILD(n, name_i), "assignment to None");
-	return NULL;
+        ast_error(CHILD(n, name_i), "assignment to None");
+        return NULL;
     }
     args = ast_for_arguments(c, CHILD(n, name_i + 1));
     if (!args)
-	return NULL;
+        return NULL;
     body = ast_for_suite(c, CHILD(n, name_i + 3));
     if (!body)
-	return NULL;
+        return NULL;
 
     return FunctionDef(name, args, body, decorator_seq, LINENO(n),
-		       n->n_col_offset, c->c_arena);
+                       n->n_col_offset, c->c_arena);
 }
 
 static expr_ty
@@ -867,20 +867,20 @@ ast_for_lambdef(struct compiling *c, const node *n)
     expr_ty expression;
 
     if (NCH(n) == 3) {
-	args = arguments(NULL, NULL, NULL, NULL, c->c_arena);
-	if (!args)
-	    return NULL;
-	expression = ast_for_expr(c, CHILD(n, 2));
-	if (!expression)
-	    return NULL;
+        args = arguments(NULL, NULL, NULL, NULL, c->c_arena);
+        if (!args)
+            return NULL;
+        expression = ast_for_expr(c, CHILD(n, 2));
+        if (!expression)
+            return NULL;
     }
     else {
-	args = ast_for_arguments(c, CHILD(n, 1));
-	if (!args)
-	    return NULL;
-	expression = ast_for_expr(c, CHILD(n, 3));
-	if (!expression)
-	    return NULL;
+        args = ast_for_arguments(c, CHILD(n, 1));
+        if (!args)
+            return NULL;
+        expression = ast_for_expr(c, CHILD(n, 3));
+        if (!expression)
+            return NULL;
     }
 
     return Lambda(args, expression, LINENO(n), n->n_col_offset, c->c_arena);
@@ -895,15 +895,15 @@ ast_for_ifexpr(struct compiling *c, const node *n)
     assert(NCH(n) == 5);
     body = ast_for_expr(c, CHILD(n, 0));
     if (!body)
-	return NULL;
+        return NULL;
     expression = ast_for_expr(c, CHILD(n, 2));
     if (!expression)
-	return NULL;
+        return NULL;
     orelse = ast_for_expr(c, CHILD(n, 4));
     if (!orelse)
-	return NULL;
+        return NULL;
     return IfExp(expression, body, orelse, LINENO(n), n->n_col_offset,
-		 c->c_arena);
+                 c->c_arena);
 }
 
 /* XXX(nnorwitz): the listcomp and genexpr code should be refactored
@@ -926,21 +926,21 @@ count_list_fors(const node *n)
     n_fors++;
     REQ(ch, list_for);
     if (NCH(ch) == 5)
-	ch = CHILD(ch, 4);
+        ch = CHILD(ch, 4);
     else
-	return n_fors;
+        return n_fors;
  count_list_iter:
     REQ(ch, list_iter);
     ch = CHILD(ch, 0);
     if (TYPE(ch) == list_for)
-	goto count_list_for;
+        goto count_list_for;
     else if (TYPE(ch) == list_if) {
-	if (NCH(ch) == 3) {
-	    ch = CHILD(ch, 2);
-	    goto count_list_iter;
-	}
-	else
-	    return n_fors;
+        if (NCH(ch) == 3) {
+            ch = CHILD(ch, 2);
+            goto count_list_iter;
+        }
+        else
+            return n_fors;
     }
 
     /* Should never be reached */
@@ -961,12 +961,12 @@ count_list_ifs(const node *n)
  count_list_iter:
     REQ(n, list_iter);
     if (TYPE(CHILD(n, 0)) == list_for)
-	return n_ifs;
+        return n_ifs;
     n = CHILD(n, 0);
     REQ(n, list_if);
     n_ifs++;
     if (NCH(n) == 2)
-	return n_ifs;
+        return n_ifs;
     n = CHILD(n, 2);
     goto count_list_iter;
 }
@@ -990,85 +990,85 @@ ast_for_listcomp(struct compiling *c, const node *n)
 
     elt = ast_for_expr(c, CHILD(n, 0));
     if (!elt)
-	return NULL;
+        return NULL;
 
     n_fors = count_list_fors(n);
     if (n_fors == -1)
-	return NULL;
+        return NULL;
 
     listcomps = asdl_seq_new(n_fors, c->c_arena);
     if (!listcomps)
-	return NULL;
+        return NULL;
 
     ch = CHILD(n, 1);
     for (i = 0; i < n_fors; i++) {
-	comprehension_ty lc;
-	asdl_seq *t;
-	expr_ty expression;
-	node *for_ch;
-
-	REQ(ch, list_for);
-
-	for_ch = CHILD(ch, 1);
-	t = ast_for_exprlist(c, for_ch, Store);
-	if (!t)
-	    return NULL;
-	expression = ast_for_testlist(c, CHILD(ch, 3));
-	if (!expression)
-	    return NULL;
-
-	/* Check the # of children rather than the length of t, since
-	   [x for x, in ... ] has 1 element in t, but still requires a Tuple. */
-	if (NCH(for_ch) == 1)
-	    lc = comprehension((expr_ty)asdl_seq_GET(t, 0), expression, NULL,
-			       c->c_arena);
-	else
-	    lc = comprehension(Tuple(t, Store, LINENO(ch), ch->n_col_offset,
-				     c->c_arena),
-			       expression, NULL, c->c_arena);
-	if (!lc)
-	    return NULL;
-
-	if (NCH(ch) == 5) {
-	    int j, n_ifs;
-	    asdl_seq *ifs;
-	    expr_ty list_for_expr;
-
-	    ch = CHILD(ch, 4);
-	    n_ifs = count_list_ifs(ch);
-	    if (n_ifs == -1)
-		return NULL;
-
-	    ifs = asdl_seq_new(n_ifs, c->c_arena);
-	    if (!ifs)
-		return NULL;
-
-	    for (j = 0; j < n_ifs; j++) {
-	    REQ(ch, list_iter);
-		    ch = CHILD(ch, 0);
-		    REQ(ch, list_if);
-            
-		list_for_expr = ast_for_expr(c, CHILD(ch, 1));
-		if (!list_for_expr)
-			return NULL;
-
-		asdl_seq_SET(ifs, j, list_for_expr);
-		if (NCH(ch) == 3)
-		    ch = CHILD(ch, 2);
-		}
-		/* on exit, must guarantee that ch is a list_for */
-		if (TYPE(ch) == list_iter)
-			ch = CHILD(ch, 0);
-	    lc->ifs = ifs;
-	    }
-	    asdl_seq_SET(listcomps, i, lc);
+        comprehension_ty lc;
+        asdl_seq *t;
+        expr_ty expression;
+        node *for_ch;
+        
+        REQ(ch, list_for);
+        
+        for_ch = CHILD(ch, 1);
+        t = ast_for_exprlist(c, for_ch, Store);
+        if (!t)
+            return NULL;
+        expression = ast_for_testlist(c, CHILD(ch, 3));
+        if (!expression)
+            return NULL;
+        
+        /* Check the # of children rather than the length of t, since
+           [x for x, in ... ] has 1 element in t, but still requires a Tuple.
+        */
+        if (NCH(for_ch) == 1)
+            lc = comprehension((expr_ty)asdl_seq_GET(t, 0), expression, NULL,
+                               c->c_arena);
+        else
+            lc = comprehension(Tuple(t, Store, LINENO(ch), ch->n_col_offset,
+                                     c->c_arena),
+                               expression, NULL, c->c_arena);
+        if (!lc)
+            return NULL;
+
+        if (NCH(ch) == 5) {
+            int j, n_ifs;
+            asdl_seq *ifs;
+            expr_ty list_for_expr;
+
+            ch = CHILD(ch, 4);
+            n_ifs = count_list_ifs(ch);
+            if (n_ifs == -1)
+                return NULL;
+
+            ifs = asdl_seq_new(n_ifs, c->c_arena);
+            if (!ifs)
+                return NULL;
+
+            for (j = 0; j < n_ifs; j++) {
+                REQ(ch, list_iter);
+                ch = CHILD(ch, 0);
+                REQ(ch, list_if);
+                
+                list_for_expr = ast_for_expr(c, CHILD(ch, 1));
+                if (!list_for_expr)
+                    return NULL;
+                
+                asdl_seq_SET(ifs, j, list_for_expr);
+                if (NCH(ch) == 3)
+                    ch = CHILD(ch, 2);
+            }
+            /* on exit, must guarantee that ch is a list_for */
+            if (TYPE(ch) == list_iter)
+                ch = CHILD(ch, 0);
+            lc->ifs = ifs;
+        }
+        asdl_seq_SET(listcomps, i, lc);
     }
 
     return ListComp(elt, listcomps, LINENO(n), n->n_col_offset, c->c_arena);
 }
 
-/*
-   Count the number of 'for' loops in a generator expression.
+/* Count the number of 'for' loops in a generator expression.
 
    Helper for ast_for_genexp().
 */
@@ -1076,34 +1076,34 @@ ast_for_listcomp(struct compiling *c, const node *n)
 static int
 count_gen_fors(const node *n)
 {
-	int n_fors = 0;
-	node *ch = CHILD(n, 1);
+    int n_fors = 0;
+    node *ch = CHILD(n, 1);
 
  count_gen_for:
-	n_fors++;
-	REQ(ch, gen_for);
-	if (NCH(ch) == 5)
-		ch = CHILD(ch, 4);
-	else
-		return n_fors;
+    n_fors++;
+    REQ(ch, gen_for);
+    if (NCH(ch) == 5)
+        ch = CHILD(ch, 4);
+    else
+        return n_fors;
  count_gen_iter:
-	REQ(ch, gen_iter);
-	ch = CHILD(ch, 0);
-	if (TYPE(ch) == gen_for)
-		goto count_gen_for;
-	else if (TYPE(ch) == gen_if) {
-		if (NCH(ch) == 3) {
-			ch = CHILD(ch, 2);
-			goto count_gen_iter;
-		}
-		else
-		    return n_fors;
-	}
-
-	/* Should never be reached */
-	PyErr_SetString(PyExc_SystemError,
-			"logic error in count_gen_fors");
-	return -1;
+    REQ(ch, gen_iter);
+    ch = CHILD(ch, 0);
+    if (TYPE(ch) == gen_for)
+        goto count_gen_for;
+    else if (TYPE(ch) == gen_if) {
+        if (NCH(ch) == 3) {
+            ch = CHILD(ch, 2);
+            goto count_gen_iter;
+        }
+        else
+            return n_fors;
+    }
+    
+    /* Should never be reached */
+    PyErr_SetString(PyExc_SystemError,
+                    "logic error in count_gen_fors");
+    return -1;
 }
 
 /* Count the number of 'if' statements in a generator expression.
@@ -1114,19 +1114,19 @@ count_gen_fors(const node *n)
 static int
 count_gen_ifs(const node *n)
 {
-	int n_ifs = 0;
-
-	while (1) {
-		REQ(n, gen_iter);
-		if (TYPE(CHILD(n, 0)) == gen_for)
-			return n_ifs;
-		n = CHILD(n, 0);
-		REQ(n, gen_if);
-		n_ifs++;
-		if (NCH(n) == 2)
-			return n_ifs;
-		n = CHILD(n, 2);
-	}
+    int n_ifs = 0;
+
+    while (1) {
+        REQ(n, gen_iter);
+        if (TYPE(CHILD(n, 0)) == gen_for)
+            return n_ifs;
+        n = CHILD(n, 0);
+        REQ(n, gen_if);
+        n_ifs++;
+        if (NCH(n) == 2)
+            return n_ifs;
+        n = CHILD(n, 2);
+    }
 }
 
 /* TODO(jhylton): Combine with list comprehension code? */
@@ -1134,7 +1134,7 @@ static expr_ty
 ast_for_genexp(struct compiling *c, const node *n)
 {
     /* testlist_gexp: test ( gen_for | (',' test)* [','] )
-       argument: [test '='] test [gen_for]	 # Really [keyword '='] test */
+       argument: [test '='] test [gen_for]       # Really [keyword '='] test */
     expr_ty elt;
     asdl_seq *genexps;
     int i, n_fors;
@@ -1145,77 +1145,77 @@ ast_for_genexp(struct compiling *c, const node *n)
     
     elt = ast_for_expr(c, CHILD(n, 0));
     if (!elt)
-	return NULL;
+        return NULL;
     
     n_fors = count_gen_fors(n);
     if (n_fors == -1)
-	return NULL;
+        return NULL;
 
     genexps = asdl_seq_new(n_fors, c->c_arena);
     if (!genexps)
-	return NULL;
+        return NULL;
 
     ch = CHILD(n, 1);
     for (i = 0; i < n_fors; i++) {
-	comprehension_ty ge;
-	asdl_seq *t;
-	expr_ty expression;
-	node *for_ch;
-	
-	REQ(ch, gen_for);
-	
-	for_ch = CHILD(ch, 1);
-	t = ast_for_exprlist(c, for_ch, Store);
-	if (!t)
-	    return NULL;
-	expression = ast_for_expr(c, CHILD(ch, 3));
-	if (!expression)
-	    return NULL;
-
-	/* Check the # of children rather than the length of t, since
-	   (x for x, in ...) has 1 element in t, but still requires a Tuple. */
-	if (NCH(for_ch) == 1)
-	    ge = comprehension((expr_ty)asdl_seq_GET(t, 0), expression,
-			       NULL, c->c_arena);
-	else
-	    ge = comprehension(Tuple(t, Store, LINENO(ch), ch->n_col_offset,
-				     c->c_arena),
-			       expression, NULL, c->c_arena);
-
-	if (!ge)
-	    return NULL;
-
-	if (NCH(ch) == 5) {
-	    int j, n_ifs;
-	    asdl_seq *ifs;
-	    
-	    ch = CHILD(ch, 4);
-	    n_ifs = count_gen_ifs(ch);
-	    if (n_ifs == -1)
-		return NULL;
-
-	    ifs = asdl_seq_new(n_ifs, c->c_arena);
-	    if (!ifs)
-		return NULL;
-
-	    for (j = 0; j < n_ifs; j++) {
-		REQ(ch, gen_iter);
-		ch = CHILD(ch, 0);
-		REQ(ch, gen_if);
-		
-		expression = ast_for_expr(c, CHILD(ch, 1));
-		if (!expression)
-		    return NULL;
-		asdl_seq_SET(ifs, j, expression);
-		if (NCH(ch) == 3)
-		    ch = CHILD(ch, 2);
-	    }
-	    /* on exit, must guarantee that ch is a gen_for */
-	    if (TYPE(ch) == gen_iter)
-		ch = CHILD(ch, 0);
-	    ge->ifs = ifs;
-	}
-	asdl_seq_SET(genexps, i, ge);
+        comprehension_ty ge;
+        asdl_seq *t;
+        expr_ty expression;
+        node *for_ch;
+        
+        REQ(ch, gen_for);
+        
+        for_ch = CHILD(ch, 1);
+        t = ast_for_exprlist(c, for_ch, Store);
+        if (!t)
+            return NULL;
+        expression = ast_for_expr(c, CHILD(ch, 3));
+        if (!expression)
+            return NULL;
+
+        /* Check the # of children rather than the length of t, since
+           (x for x, in ...) has 1 element in t, but still requires a Tuple. */
+        if (NCH(for_ch) == 1)
+            ge = comprehension((expr_ty)asdl_seq_GET(t, 0), expression,
+                               NULL, c->c_arena);
+        else
+            ge = comprehension(Tuple(t, Store, LINENO(ch), ch->n_col_offset,
+                                     c->c_arena),
+                               expression, NULL, c->c_arena);
+
+        if (!ge)
+            return NULL;
+
+        if (NCH(ch) == 5) {
+            int j, n_ifs;
+            asdl_seq *ifs;
+            
+            ch = CHILD(ch, 4);
+            n_ifs = count_gen_ifs(ch);
+            if (n_ifs == -1)
+                return NULL;
+
+            ifs = asdl_seq_new(n_ifs, c->c_arena);
+            if (!ifs)
+                return NULL;
+
+            for (j = 0; j < n_ifs; j++) {
+                REQ(ch, gen_iter);
+                ch = CHILD(ch, 0);
+                REQ(ch, gen_if);
+                
+                expression = ast_for_expr(c, CHILD(ch, 1));
+                if (!expression)
+                    return NULL;
+                asdl_seq_SET(ifs, j, expression);
+                if (NCH(ch) == 3)
+                    ch = CHILD(ch, 2);
+            }
+            /* on exit, must guarantee that ch is a gen_for */
+            if (TYPE(ch) == gen_iter)
+                ch = CHILD(ch, 0);
+            ge->ifs = ifs;
+        }
+        asdl_seq_SET(genexps, i, ge);
     }
     
     return GeneratorExp(elt, genexps, LINENO(n), n->n_col_offset, c->c_arena);
@@ -1231,96 +1231,97 @@ ast_for_atom(struct compiling *c, const node *n)
     
     switch (TYPE(ch)) {
     case NAME:
-	/* All names start in Load context, but may later be
-	   changed. */
-	return Name(NEW_IDENTIFIER(ch), Load, LINENO(n), n->n_col_offset, c->c_arena);
+        /* All names start in Load context, but may later be
+           changed. */
+        return Name(NEW_IDENTIFIER(ch), Load, LINENO(n), n->n_col_offset,
+                    c->c_arena);
     case STRING: {
-	PyObject *str = parsestrplus(c, n);
-	if (!str)
-	    return NULL;
+        PyObject *str = parsestrplus(c, n);
+        if (!str)
+            return NULL;
 
-	PyArena_AddPyObject(c->c_arena, str);
-	return Str(str, LINENO(n), n->n_col_offset, c->c_arena);
+        PyArena_AddPyObject(c->c_arena, str);
+        return Str(str, LINENO(n), n->n_col_offset, c->c_arena);
     }
     case NUMBER: {
-	PyObject *pynum = parsenumber(STR(ch));
-	if (!pynum)
-	    return NULL;
+        PyObject *pynum = parsenumber(STR(ch));
+        if (!pynum)
+            return NULL;
 
-	PyArena_AddPyObject(c->c_arena, pynum);
-	return Num(pynum, LINENO(n), n->n_col_offset, c->c_arena);
+        PyArena_AddPyObject(c->c_arena, pynum);
+        return Num(pynum, LINENO(n), n->n_col_offset, c->c_arena);
     }
     case LPAR: /* some parenthesized expressions */
-	ch = CHILD(n, 1);
-	
-	if (TYPE(ch) == RPAR)
-	    return Tuple(NULL, Load, LINENO(n), n->n_col_offset, c->c_arena);
-	
-	if (TYPE(ch) == yield_expr)
-	    return ast_for_expr(c, ch);
-	
-	if ((NCH(ch) > 1) && (TYPE(CHILD(ch, 1)) == gen_for))
-	    return ast_for_genexp(c, ch);
-	
-	return ast_for_testlist_gexp(c, ch);
+        ch = CHILD(n, 1);
+        
+        if (TYPE(ch) == RPAR)
+            return Tuple(NULL, Load, LINENO(n), n->n_col_offset, c->c_arena);
+        
+        if (TYPE(ch) == yield_expr)
+            return ast_for_expr(c, ch);
+        
+        if ((NCH(ch) > 1) && (TYPE(CHILD(ch, 1)) == gen_for))
+            return ast_for_genexp(c, ch);
+        
+        return ast_for_testlist_gexp(c, ch);
     case LSQB: /* list (or list comprehension) */
-	ch = CHILD(n, 1);
-	
-	if (TYPE(ch) == RSQB)
-	    return List(NULL, Load, LINENO(n), n->n_col_offset, c->c_arena);
-	
-	REQ(ch, listmaker);
-	if (NCH(ch) == 1 || TYPE(CHILD(ch, 1)) == COMMA) {
-	    asdl_seq *elts = seq_for_testlist(c, ch);
-	    if (!elts)
-		return NULL;
-
-	    return List(elts, Load, LINENO(n), n->n_col_offset, c->c_arena);
-	}
-	else
-	    return ast_for_listcomp(c, ch);
+        ch = CHILD(n, 1);
+        
+        if (TYPE(ch) == RSQB)
+            return List(NULL, Load, LINENO(n), n->n_col_offset, c->c_arena);
+        
+        REQ(ch, listmaker);
+        if (NCH(ch) == 1 || TYPE(CHILD(ch, 1)) == COMMA) {
+            asdl_seq *elts = seq_for_testlist(c, ch);
+            if (!elts)
+                return NULL;
+
+            return List(elts, Load, LINENO(n), n->n_col_offset, c->c_arena);
+        }
+        else
+            return ast_for_listcomp(c, ch);
     case LBRACE: {
-	/* dictmaker: test ':' test (',' test ':' test)* [','] */
-	int i, size;
-	asdl_seq *keys, *values;
-	
-	ch = CHILD(n, 1);
-	size = (NCH(ch) + 1) / 4; /* +1 in case no trailing comma */
-	keys = asdl_seq_new(size, c->c_arena);
-	if (!keys)
-	    return NULL;
-	
-	values = asdl_seq_new(size, c->c_arena);
-	if (!values)
-	    return NULL;
-	
-	for (i = 0; i < NCH(ch); i += 4) {
-	    expr_ty expression;
-	    
-	    expression = ast_for_expr(c, CHILD(ch, i));
-	    if (!expression)
-		return NULL;
-
-	    asdl_seq_SET(keys, i / 4, expression);
-
-	    expression = ast_for_expr(c, CHILD(ch, i + 2));
-	    if (!expression)
-		return NULL;
-
-	    asdl_seq_SET(values, i / 4, expression);
-	}
-	return Dict(keys, values, LINENO(n), n->n_col_offset, c->c_arena);
+        /* dictmaker: test ':' test (',' test ':' test)* [','] */
+        int i, size;
+        asdl_seq *keys, *values;
+        
+        ch = CHILD(n, 1);
+        size = (NCH(ch) + 1) / 4; /* +1 in case no trailing comma */
+        keys = asdl_seq_new(size, c->c_arena);
+        if (!keys)
+            return NULL;
+        
+        values = asdl_seq_new(size, c->c_arena);
+        if (!values)
+            return NULL;
+        
+        for (i = 0; i < NCH(ch); i += 4) {
+            expr_ty expression;
+            
+            expression = ast_for_expr(c, CHILD(ch, i));
+            if (!expression)
+                return NULL;
+
+            asdl_seq_SET(keys, i / 4, expression);
+
+            expression = ast_for_expr(c, CHILD(ch, i + 2));
+            if (!expression)
+                return NULL;
+
+            asdl_seq_SET(values, i / 4, expression);
+        }
+        return Dict(keys, values, LINENO(n), n->n_col_offset, c->c_arena);
     }
     case BACKQUOTE: { /* repr */
-	expr_ty expression = ast_for_testlist(c, CHILD(n, 1));
-	if (!expression)
-	    return NULL;
+        expr_ty expression = ast_for_testlist(c, CHILD(n, 1));
+        if (!expression)
+            return NULL;
 
-	return Repr(expression, LINENO(n), n->n_col_offset, c->c_arena);
+        return Repr(expression, LINENO(n), n->n_col_offset, c->c_arena);
     }
     default:
-	PyErr_Format(PyExc_SystemError, "unhandled atom %d", TYPE(ch));
-	return NULL;
+        PyErr_Format(PyExc_SystemError, "unhandled atom %d", TYPE(ch));
+        return NULL;
     }
 }
 
@@ -1338,62 +1339,62 @@ ast_for_slice(struct compiling *c, const node *n)
     */
     ch = CHILD(n, 0);
     if (TYPE(ch) == DOT)
-	return Ellipsis(c->c_arena);
+        return Ellipsis(c->c_arena);
 
     if (NCH(n) == 1 && TYPE(ch) == test) {
-	/* 'step' variable hold no significance in terms of being used over
-	   other vars */
-	step = ast_for_expr(c, ch); 
-	if (!step)
-	    return NULL;
-	    
-	return Index(step, c->c_arena);
+        /* 'step' variable hold no significance in terms of being used over
+           other vars */
+        step = ast_for_expr(c, ch); 
+        if (!step)
+            return NULL;
+            
+        return Index(step, c->c_arena);
     }
 
     if (TYPE(ch) == test) {
-	lower = ast_for_expr(c, ch);
-	if (!lower)
-	    return NULL;
+        lower = ast_for_expr(c, ch);
+        if (!lower)
+            return NULL;
     }
 
     /* If there's an upper bound it's in the second or third position. */
     if (TYPE(ch) == COLON) {
-	if (NCH(n) > 1) {
-	    node *n2 = CHILD(n, 1);
-
-	    if (TYPE(n2) == test) {
-		upper = ast_for_expr(c, n2);
-		if (!upper)
-		    return NULL;
-	    }
-	}
+        if (NCH(n) > 1) {
+            node *n2 = CHILD(n, 1);
+
+            if (TYPE(n2) == test) {
+                upper = ast_for_expr(c, n2);
+                if (!upper)
+                    return NULL;
+            }
+        }
     } else if (NCH(n) > 2) {
-	node *n2 = CHILD(n, 2);
+        node *n2 = CHILD(n, 2);
 
-	if (TYPE(n2) == test) {
-	    upper = ast_for_expr(c, n2);
-	    if (!upper)
-		return NULL;
-	}
+        if (TYPE(n2) == test) {
+            upper = ast_for_expr(c, n2);
+            if (!upper)
+                return NULL;
+        }
     }
 
     ch = CHILD(n, NCH(n) - 1);
     if (TYPE(ch) == sliceop) {
-	if (NCH(ch) == 1) {
-	    /* No expression, so step is None */
-	    ch = CHILD(ch, 0);
-	    step = Name(new_identifier("None", c->c_arena), Load,
-			LINENO(ch), ch->n_col_offset, c->c_arena);
-	    if (!step)
-		return NULL;
-	} else {
-	    ch = CHILD(ch, 1);
-	    if (TYPE(ch) == test) {
-		step = ast_for_expr(c, ch);
-		if (!step)
-		    return NULL;
-	    }
-	}
+        if (NCH(ch) == 1) {
+            /* No expression, so step is None */
+            ch = CHILD(ch, 0);
+            step = Name(new_identifier("None", c->c_arena), Load,
+                        LINENO(ch), ch->n_col_offset, c->c_arena);
+            if (!step)
+                return NULL;
+        } else {
+            ch = CHILD(ch, 1);
+            if (TYPE(ch) == test) {
+                step = ast_for_expr(c, ch);
+                if (!step)
+                    return NULL;
+            }
+        }
     }
 
     return Slice(lower, upper, step, c->c_arena);
@@ -1402,53 +1403,53 @@ ast_for_slice(struct compiling *c, const node *n)
 static expr_ty
 ast_for_binop(struct compiling *c, const node *n)
 {
-	/* Must account for a sequence of expressions.
-	   How should A op B op C by represented?  
-	   BinOp(BinOp(A, op, B), op, C).
-	*/
-
-	int i, nops;
-	expr_ty expr1, expr2, result;
-	operator_ty newoperator;
-
-	expr1 = ast_for_expr(c, CHILD(n, 0));
-	if (!expr1)
-	    return NULL;
-
-	expr2 = ast_for_expr(c, CHILD(n, 2));
-	if (!expr2)
-	    return NULL;
-
-	newoperator = get_operator(CHILD(n, 1));
-	if (!newoperator)
-	    return NULL;
-
-	result = BinOp(expr1, newoperator, expr2, LINENO(n), n->n_col_offset,
-		       c->c_arena);
-	if (!result)
-	    return NULL;
-
-	nops = (NCH(n) - 1) / 2;
-	for (i = 1; i < nops; i++) {
-		expr_ty tmp_result, tmp;
-		const node* next_oper = CHILD(n, i * 2 + 1);
-
-		newoperator = get_operator(next_oper);
-		if (!newoperator)
-		    return NULL;
-
-		tmp = ast_for_expr(c, CHILD(n, i * 2 + 2));
-		if (!tmp)
-		    return NULL;
-
-		tmp_result = BinOp(result, newoperator, tmp, 
-				   LINENO(next_oper), next_oper->n_col_offset,
-				   c->c_arena);
-		if (!tmp) 
-			return NULL;
-		result = tmp_result;
-	}
-	return result;
+        /* Must account for a sequence of expressions.
+           How should A op B op C by represented?  
+           BinOp(BinOp(A, op, B), op, C).
+        */
+
+        int i, nops;
+        expr_ty expr1, expr2, result;
+        operator_ty newoperator;
+
+        expr1 = ast_for_expr(c, CHILD(n, 0));
+        if (!expr1)
+            return NULL;
+
+        expr2 = ast_for_expr(c, CHILD(n, 2));
+        if (!expr2)
+            return NULL;
+
+        newoperator = get_operator(CHILD(n, 1));
+        if (!newoperator)
+            return NULL;
+
+        result = BinOp(expr1, newoperator, expr2, LINENO(n), n->n_col_offset,
+                       c->c_arena);
+        if (!result)
+            return NULL;
+
+        nops = (NCH(n) - 1) / 2;
+        for (i = 1; i < nops; i++) {
+                expr_ty tmp_result, tmp;
+                const node* next_oper = CHILD(n, i * 2 + 1);
+
+                newoperator = get_operator(next_oper);
+                if (!newoperator)
+                    return NULL;
+
+                tmp = ast_for_expr(c, CHILD(n, i * 2 + 2));
+                if (!tmp)
+                    return NULL;
+
+                tmp_result = BinOp(result, newoperator, tmp, 
+                                   LINENO(next_oper), next_oper->n_col_offset,
+                                   c->c_arena);
+                if (!tmp) 
+                        return NULL;
+                result = tmp_result;
+        }
+        return result;
 }
 
 static expr_ty
@@ -1460,67 +1461,67 @@ ast_for_trailer(struct compiling *c, const node *n, expr_ty left_expr)
      */
     REQ(n, trailer);
     if (TYPE(CHILD(n, 0)) == LPAR) {
-	if (NCH(n) == 2)
-	    return Call(left_expr, NULL, NULL, NULL, NULL, LINENO(n),
-			n->n_col_offset, c->c_arena);
-	else
-	    return ast_for_call(c, CHILD(n, 1), left_expr);
+        if (NCH(n) == 2)
+            return Call(left_expr, NULL, NULL, NULL, NULL, LINENO(n),
+                        n->n_col_offset, c->c_arena);
+        else
+            return ast_for_call(c, CHILD(n, 1), left_expr);
     }
     else if (TYPE(CHILD(n, 0)) == DOT ) {
-	return Attribute(left_expr, NEW_IDENTIFIER(CHILD(n, 1)), Load,
-			 LINENO(n), n->n_col_offset, c->c_arena);
+        return Attribute(left_expr, NEW_IDENTIFIER(CHILD(n, 1)), Load,
+                         LINENO(n), n->n_col_offset, c->c_arena);
     }
     else {
-	REQ(CHILD(n, 0), LSQB);
-	REQ(CHILD(n, 2), RSQB);
-	n = CHILD(n, 1);
-	if (NCH(n) == 1) {
-	    slice_ty slc = ast_for_slice(c, CHILD(n, 0));
-	    if (!slc)
-		return NULL;
-	    return Subscript(left_expr, slc, Load, LINENO(n), n->n_col_offset,
-			     c->c_arena);
-	}
-	else {
-	    /* The grammar is ambiguous here. The ambiguity is resolved 
-	       by treating the sequence as a tuple literal if there are
-	       no slice features.
-	    */
-	    int j;
-	    slice_ty slc;
-	    expr_ty e;
-	    bool simple = true;
-	    asdl_seq *slices, *elts;
-	    slices = asdl_seq_new((NCH(n) + 1) / 2, c->c_arena);
-	    if (!slices)
-		return NULL;
-	    for (j = 0; j < NCH(n); j += 2) {
-		slc = ast_for_slice(c, CHILD(n, j));
-		if (!slc)
-		    return NULL;
-		if (slc->kind != Index_kind)
-		    simple = false;
-		asdl_seq_SET(slices, j / 2, slc);
-	    }
-	    if (!simple) {
-		return Subscript(left_expr, ExtSlice(slices, c->c_arena),
-				 Load, LINENO(n), n->n_col_offset, c->c_arena);
-	    }
-	    /* extract Index values and put them in a Tuple */
-	    elts = asdl_seq_new(asdl_seq_LEN(slices), c->c_arena);
-	    if (!elts)
-		return NULL;
-	    for (j = 0; j < asdl_seq_LEN(slices); ++j) {
-		slc = (slice_ty)asdl_seq_GET(slices, j);
-		assert(slc->kind == Index_kind	&& slc->v.Index.value);
-		asdl_seq_SET(elts, j, slc->v.Index.value);
-	    }
-	    e = Tuple(elts, Load, LINENO(n), n->n_col_offset, c->c_arena);
-	    if (!e)
-		return NULL;
-	    return Subscript(left_expr, Index(e, c->c_arena),
-			     Load, LINENO(n), n->n_col_offset, c->c_arena);
-	}
+        REQ(CHILD(n, 0), LSQB);
+        REQ(CHILD(n, 2), RSQB);
+        n = CHILD(n, 1);
+        if (NCH(n) == 1) {
+            slice_ty slc = ast_for_slice(c, CHILD(n, 0));
+            if (!slc)
+                return NULL;
+            return Subscript(left_expr, slc, Load, LINENO(n), n->n_col_offset,
+                             c->c_arena);
+        }
+        else {
+            /* The grammar is ambiguous here. The ambiguity is resolved 
+               by treating the sequence as a tuple literal if there are
+               no slice features.
+            */
+            int j;
+            slice_ty slc;
+            expr_ty e;
+            bool simple = true;
+            asdl_seq *slices, *elts;
+            slices = asdl_seq_new((NCH(n) + 1) / 2, c->c_arena);
+            if (!slices)
+                return NULL;
+            for (j = 0; j < NCH(n); j += 2) {
+                slc = ast_for_slice(c, CHILD(n, j));
+                if (!slc)
+                    return NULL;
+                if (slc->kind != Index_kind)
+                    simple = false;
+                asdl_seq_SET(slices, j / 2, slc);
+            }
+            if (!simple) {
+                return Subscript(left_expr, ExtSlice(slices, c->c_arena),
+                                 Load, LINENO(n), n->n_col_offset, c->c_arena);
+            }
+            /* extract Index values and put them in a Tuple */
+            elts = asdl_seq_new(asdl_seq_LEN(slices), c->c_arena);
+            if (!elts)
+                return NULL;
+            for (j = 0; j < asdl_seq_LEN(slices); ++j) {
+                slc = (slice_ty)asdl_seq_GET(slices, j);
+                assert(slc->kind == Index_kind  && slc->v.Index.value);
+                asdl_seq_SET(elts, j, slc->v.Index.value);
+            }
+            e = Tuple(elts, Load, LINENO(n), n->n_col_offset, c->c_arena);
+            if (!e)
+                return NULL;
+            return Subscript(left_expr, Index(e, c->c_arena),
+                             Load, LINENO(n), n->n_col_offset, c->c_arena);
+        }
     }
 }
 
@@ -1531,47 +1532,47 @@ ast_for_factor(struct compiling *c, const node *n)
     expr_ty expression;
 
     /* If the unary - operator is applied to a constant, don't generate
-       a UNARY_NEGATIVE opcode.	 Just store the approriate value as a
+       a UNARY_NEGATIVE opcode.  Just store the approriate value as a
        constant.  The peephole optimizer already does something like
        this but it doesn't handle the case where the constant is
        (sys.maxint - 1).  In that case, we want a PyIntObject, not a
        PyLongObject.
     */
-    if (TYPE(CHILD(n, 0)) == MINUS
-	&& NCH(n) == 2
-	&& TYPE((pfactor = CHILD(n, 1))) == factor
-	&& NCH(pfactor) == 1
-	&& TYPE((ppower = CHILD(pfactor, 0))) == power
-	&& NCH(ppower) == 1
-	&& TYPE((patom = CHILD(ppower, 0))) == atom
-	&& TYPE((pnum = CHILD(patom, 0))) == NUMBER) {
-	char *s = PyObject_MALLOC(strlen(STR(pnum)) + 2);
-	if (s == NULL)
-	    return NULL;
-	s[0] = '-';
-	strcpy(s + 1, STR(pnum));
-	PyObject_FREE(STR(pnum));
-	STR(pnum) = s;
-	return ast_for_atom(c, patom);
+    if (TYPE(CHILD(n, 0)) == MINUS &&
+        NCH(n) == 2 &&
+        TYPE((pfactor = CHILD(n, 1))) == factor &&
+        NCH(pfactor) == 1 &&
+        TYPE((ppower = CHILD(pfactor, 0))) == power &&
+        NCH(ppower) == 1 &&
+        TYPE((patom = CHILD(ppower, 0))) == atom &&
+        TYPE((pnum = CHILD(patom, 0))) == NUMBER) {
+        char *s = PyObject_MALLOC(strlen(STR(pnum)) + 2);
+        if (s == NULL)
+            return NULL;
+        s[0] = '-';
+        strcpy(s + 1, STR(pnum));
+        PyObject_FREE(STR(pnum));
+        STR(pnum) = s;
+        return ast_for_atom(c, patom);
     }
 
     expression = ast_for_expr(c, CHILD(n, 1));
     if (!expression)
-	return NULL;
+        return NULL;
 
     switch (TYPE(CHILD(n, 0))) {
-	case PLUS:
-	    return UnaryOp(UAdd, expression, LINENO(n), n->n_col_offset,
-			   c->c_arena);
-	case MINUS:
-	    return UnaryOp(USub, expression, LINENO(n), n->n_col_offset,
-			   c->c_arena);
-	case TILDE:
-	    return UnaryOp(Invert, expression, LINENO(n),
-			   n->n_col_offset, c->c_arena);
+        case PLUS:
+            return UnaryOp(UAdd, expression, LINENO(n), n->n_col_offset,
+                           c->c_arena);
+        case MINUS:
+            return UnaryOp(USub, expression, LINENO(n), n->n_col_offset,
+                           c->c_arena);
+        case TILDE:
+            return UnaryOp(Invert, expression, LINENO(n),
+                           n->n_col_offset, c->c_arena);
     }
     PyErr_Format(PyExc_SystemError, "unhandled factor: %d",
-		 TYPE(CHILD(n, 0)));
+                 TYPE(CHILD(n, 0)));
     return NULL;
 }
 
@@ -1585,28 +1586,28 @@ ast_for_power(struct compiling *c, const node *n)
     REQ(n, power);
     e = ast_for_atom(c, CHILD(n, 0));
     if (!e)
-	return NULL;
+        return NULL;
     if (NCH(n) == 1)
-	return e;
+        return e;
     for (i = 1; i < NCH(n); i++) {
-	node *ch = CHILD(n, i);
-	if (TYPE(ch) != trailer)
-	    break;
-	tmp = ast_for_trailer(c, ch, e);
-	if (!tmp)
-	    return NULL;
-	tmp->lineno = e->lineno;
-	tmp->col_offset = e->col_offset;
-	e = tmp;
+        node *ch = CHILD(n, i);
+        if (TYPE(ch) != trailer)
+            break;
+        tmp = ast_for_trailer(c, ch, e);
+        if (!tmp)
+            return NULL;
+        tmp->lineno = e->lineno;
+        tmp->col_offset = e->col_offset;
+        e = tmp;
     }
     if (TYPE(CHILD(n, NCH(n) - 1)) == factor) {
-	expr_ty f = ast_for_expr(c, CHILD(n, NCH(n) - 1));
-	if (!f)
-	    return NULL;
-	tmp = BinOp(e, Pow, f, LINENO(n), n->n_col_offset, c->c_arena);
-	if (!tmp)
-	    return NULL;
-	e = tmp;
+        expr_ty f = ast_for_expr(c, CHILD(n, NCH(n) - 1));
+        if (!f)
+            return NULL;
+        tmp = BinOp(e, Pow, f, LINENO(n), n->n_col_offset, c->c_arena);
+        if (!tmp)
+            return NULL;
+        e = tmp;
     }
     return e;
 }
@@ -1647,124 +1648,124 @@ ast_for_expr(struct compiling *c, const node *n)
 
  loop:
     switch (TYPE(n)) {
-	case test:
-	case old_test:
-	    if (TYPE(CHILD(n, 0)) == lambdef ||
-		TYPE(CHILD(n, 0)) == old_lambdef)
-		return ast_for_lambdef(c, CHILD(n, 0));
-	    else if (NCH(n) > 1)
-		return ast_for_ifexpr(c, n);
-	    /* Fallthrough */
-	case or_test:
-	case and_test:
-	    if (NCH(n) == 1) {
-		n = CHILD(n, 0);
-		goto loop;
-	    }
-	    seq = asdl_seq_new((NCH(n) + 1) / 2, c->c_arena);
-	    if (!seq)
-		return NULL;
-	    for (i = 0; i < NCH(n); i += 2) {
-		expr_ty e = ast_for_expr(c, CHILD(n, i));
-		if (!e)
-		    return NULL;
-		asdl_seq_SET(seq, i / 2, e);
-	    }
-	    if (!strcmp(STR(CHILD(n, 1)), "and"))
-		return BoolOp(And, seq, LINENO(n), n->n_col_offset,
-			      c->c_arena);
-	    assert(!strcmp(STR(CHILD(n, 1)), "or"));
-	    return BoolOp(Or, seq, LINENO(n), n->n_col_offset, c->c_arena);
-	case not_test:
-	    if (NCH(n) == 1) {
-		n = CHILD(n, 0);
-		goto loop;
-	    }
-	    else {
-		expr_ty expression = ast_for_expr(c, CHILD(n, 1));
-		if (!expression)
-		    return NULL;
-
-		return UnaryOp(Not, expression, LINENO(n), n->n_col_offset,
-			       c->c_arena);
-	    }
-	case comparison:
-	    if (NCH(n) == 1) {
-		n = CHILD(n, 0);
-		goto loop;
-	    }
-	    else {
-		expr_ty expression;
-		asdl_int_seq *ops;
-		asdl_seq *cmps;
-		ops = asdl_int_seq_new(NCH(n) / 2, c->c_arena);
-		if (!ops)
-		    return NULL;
-		cmps = asdl_seq_new(NCH(n) / 2, c->c_arena);
-		if (!cmps) {
-		    return NULL;
-		}
-		for (i = 1; i < NCH(n); i += 2) {
-		    cmpop_ty newoperator;
-
-		    newoperator = ast_for_comp_op(CHILD(n, i));
-		    if (!newoperator) {
-			return NULL;
-		    }
-
-		    expression = ast_for_expr(c, CHILD(n, i + 1));
-		    if (!expression) {
-			return NULL;
-		    }
-			
-		    asdl_seq_SET(ops, i / 2, newoperator);
-		    asdl_seq_SET(cmps, i / 2, expression);
-		}
-		expression = ast_for_expr(c, CHILD(n, 0));
-		if (!expression) {
-		    return NULL;
-		}
-		    
-		return Compare(expression, ops, cmps, LINENO(n),
-			       n->n_col_offset, c->c_arena);
-	    }
-	    break;
-
-	/* The next five cases all handle BinOps.  The main body of code
-	   is the same in each case, but the switch turned inside out to
-	   reuse the code for each type of operator.
-	 */
-	case expr:
-	case xor_expr:
-	case and_expr:
-	case shift_expr:
-	case arith_expr:
-	case term:
-	    if (NCH(n) == 1) {
-		n = CHILD(n, 0);
-		goto loop;
-	    }
-	    return ast_for_binop(c, n);
-	case yield_expr: {
-	    expr_ty exp = NULL;
-	    if (NCH(n) == 2) {
-		exp = ast_for_testlist(c, CHILD(n, 1));
-		if (!exp)
-		    return NULL;
-	    }
-	    return Yield(exp, LINENO(n), n->n_col_offset, c->c_arena);
-	}
-	case factor:
-	    if (NCH(n) == 1) {
-		n = CHILD(n, 0);
-		goto loop;
-	    }
-	    return ast_for_factor(c, n);
-	case power:
-	    return ast_for_power(c, n);
-	default:
-	    PyErr_Format(PyExc_SystemError, "unhandled expr: %d", TYPE(n));
-	    return NULL;
+        case test:
+        case old_test:
+            if (TYPE(CHILD(n, 0)) == lambdef ||
+                TYPE(CHILD(n, 0)) == old_lambdef)
+                return ast_for_lambdef(c, CHILD(n, 0));
+            else if (NCH(n) > 1)
+                return ast_for_ifexpr(c, n);
+            /* Fallthrough */
+        case or_test:
+        case and_test:
+            if (NCH(n) == 1) {
+                n = CHILD(n, 0);
+                goto loop;
+            }
+            seq = asdl_seq_new((NCH(n) + 1) / 2, c->c_arena);
+            if (!seq)
+                return NULL;
+            for (i = 0; i < NCH(n); i += 2) {
+                expr_ty e = ast_for_expr(c, CHILD(n, i));
+                if (!e)
+                    return NULL;
+                asdl_seq_SET(seq, i / 2, e);
+            }
+            if (!strcmp(STR(CHILD(n, 1)), "and"))
+                return BoolOp(And, seq, LINENO(n), n->n_col_offset,
+                              c->c_arena);
+            assert(!strcmp(STR(CHILD(n, 1)), "or"));
+            return BoolOp(Or, seq, LINENO(n), n->n_col_offset, c->c_arena);
+        case not_test:
+            if (NCH(n) == 1) {
+                n = CHILD(n, 0);
+                goto loop;
+            }
+            else {
+                expr_ty expression = ast_for_expr(c, CHILD(n, 1));
+                if (!expression)
+                    return NULL;
+
+                return UnaryOp(Not, expression, LINENO(n), n->n_col_offset,
+                               c->c_arena);
+            }
+        case comparison:
+            if (NCH(n) == 1) {
+                n = CHILD(n, 0);
+                goto loop;
+            }
+            else {
+                expr_ty expression;
+                asdl_int_seq *ops;
+                asdl_seq *cmps;
+                ops = asdl_int_seq_new(NCH(n) / 2, c->c_arena);
+                if (!ops)
+                    return NULL;
+                cmps = asdl_seq_new(NCH(n) / 2, c->c_arena);
+                if (!cmps) {
+                    return NULL;
+                }
+                for (i = 1; i < NCH(n); i += 2) {
+                    cmpop_ty newoperator;
+
+                    newoperator = ast_for_comp_op(CHILD(n, i));
+                    if (!newoperator) {
+                        return NULL;
+                    }
+
+                    expression = ast_for_expr(c, CHILD(n, i + 1));
+                    if (!expression) {
+                        return NULL;
+                    }
+                        
+                    asdl_seq_SET(ops, i / 2, newoperator);
+                    asdl_seq_SET(cmps, i / 2, expression);
+                }
+                expression = ast_for_expr(c, CHILD(n, 0));
+                if (!expression) {
+                    return NULL;
+                }
+                    
+                return Compare(expression, ops, cmps, LINENO(n),
+                               n->n_col_offset, c->c_arena);
+            }
+            break;
+
+        /* The next five cases all handle BinOps.  The main body of code
+           is the same in each case, but the switch turned inside out to
+           reuse the code for each type of operator.
+         */
+        case expr:
+        case xor_expr:
+        case and_expr:
+        case shift_expr:
+        case arith_expr:
+        case term:
+            if (NCH(n) == 1) {
+                n = CHILD(n, 0);
+                goto loop;
+            }
+            return ast_for_binop(c, n);
+        case yield_expr: {
+            expr_ty exp = NULL;
+            if (NCH(n) == 2) {
+                exp = ast_for_testlist(c, CHILD(n, 1));
+                if (!exp)
+                    return NULL;
+            }
+            return Yield(exp, LINENO(n), n->n_col_offset, c->c_arena);
+        }
+        case factor:
+            if (NCH(n) == 1) {
+                n = CHILD(n, 0);
+                goto loop;
+            }
+            return ast_for_factor(c, n);
+        case power:
+            return ast_for_power(c, n);
+        default:
+            PyErr_Format(PyExc_SystemError, "unhandled expr: %d", TYPE(n));
+            return NULL;
     }
     /* should never get here unless if error is set */
     return NULL;
@@ -1775,8 +1776,8 @@ ast_for_call(struct compiling *c, const node *n, expr_ty func)
 {
     /*
       arglist: (argument ',')* (argument [',']| '*' test [',' '**' test]
-	       | '**' test)
-      argument: [test '='] test [gen_for]	 # Really [keyword '='] test
+               | '**' test)
+      argument: [test '='] test [gen_for]        # Really [keyword '='] test
     */
 
     int i, nargs, nkeywords, ngens;
@@ -1790,20 +1791,20 @@ ast_for_call(struct compiling *c, const node *n, expr_ty func)
     nkeywords = 0;
     ngens = 0;
     for (i = 0; i < NCH(n); i++) {
-	node *ch = CHILD(n, i);
-	if (TYPE(ch) == argument) {
-	    if (NCH(ch) == 1)
-		nargs++;
-	    else if (TYPE(CHILD(ch, 1)) == gen_for)
-		ngens++;
-	    else
-		nkeywords++;
-	}
+        node *ch = CHILD(n, i);
+        if (TYPE(ch) == argument) {
+            if (NCH(ch) == 1)
+                nargs++;
+            else if (TYPE(CHILD(ch, 1)) == gen_for)
+                ngens++;
+            else
+                nkeywords++;
+        }
     }
     if (ngens > 1 || (ngens && (nargs || nkeywords))) {
-	ast_error(n, "Generator expression must be parenthesized "
-		  "if not sole argument");
-	return NULL;
+        ast_error(n, "Generator expression must be parenthesized "
+                  "if not sole argument");
+        return NULL;
     }
 
     if (nargs + nkeywords + ngens > 255) {
@@ -1813,74 +1814,76 @@ ast_for_call(struct compiling *c, const node *n, expr_ty func)
 
     args = asdl_seq_new(nargs + ngens, c->c_arena);
     if (!args)
-	return NULL;
+        return NULL;
     keywords = asdl_seq_new(nkeywords, c->c_arena);
     if (!keywords)
-	return NULL;
+        return NULL;
     nargs = 0;
     nkeywords = 0;
     for (i = 0; i < NCH(n); i++) {
-	node *ch = CHILD(n, i);
-	if (TYPE(ch) == argument) {
-	    expr_ty e;
-	    if (NCH(ch) == 1) {
-		if (nkeywords) {
-		    ast_error(CHILD(ch, 0),
-			      "non-keyword arg after keyword arg");
-		    return NULL;
-		}
-		e = ast_for_expr(c, CHILD(ch, 0));
-		if (!e)
-		    return NULL;
-		asdl_seq_SET(args, nargs++, e);
-	    }  
-	    else if (TYPE(CHILD(ch, 1)) == gen_for) {
-		e = ast_for_genexp(c, ch);
-		if (!e)
-		    return NULL;
-		asdl_seq_SET(args, nargs++, e);
-	    }
-	    else {
-		keyword_ty kw;
-		identifier key;
-
-		/* CHILD(ch, 0) is test, but must be an identifier? */ 
-		e = ast_for_expr(c, CHILD(ch, 0));
-		if (!e)
-		    return NULL;
-		/* f(lambda x: x[0] = 3) ends up getting parsed with
-		 * LHS test = lambda x: x[0], and RHS test = 3.
-		 * SF bug 132313 points out that complaining about a keyword
-		 * then is very confusing.
-		 */
-		if (e->kind == Lambda_kind) {
-		  ast_error(CHILD(ch, 0), "lambda cannot contain assignment");
-		  return NULL;
-		} else if (e->kind != Name_kind) {
-		  ast_error(CHILD(ch, 0), "keyword can't be an expression");
-		  return NULL;
-		}
-		key = e->v.Name.id;
-		e = ast_for_expr(c, CHILD(ch, 2));
-		if (!e)
-		    return NULL;
-		kw = keyword(key, e, c->c_arena);
-		if (!kw)
-		    return NULL;
-		asdl_seq_SET(keywords, nkeywords++, kw);
-	    }
-	}
-	else if (TYPE(ch) == STAR) {
-	    vararg = ast_for_expr(c, CHILD(n, i+1));
-	    i++;
-	}
-	else if (TYPE(ch) == DOUBLESTAR) {
-	    kwarg = ast_for_expr(c, CHILD(n, i+1));
-	    i++;
-	}
-    }
-
-    return Call(func, args, keywords, vararg, kwarg, func->lineno, func->col_offset, c->c_arena);
+        node *ch = CHILD(n, i);
+        if (TYPE(ch) == argument) {
+            expr_ty e;
+            if (NCH(ch) == 1) {
+                if (nkeywords) {
+                    ast_error(CHILD(ch, 0),
+                              "non-keyword arg after keyword arg");
+                    return NULL;
+                }
+                e = ast_for_expr(c, CHILD(ch, 0));
+                if (!e)
+                    return NULL;
+                asdl_seq_SET(args, nargs++, e);
+            }  
+            else if (TYPE(CHILD(ch, 1)) == gen_for) {
+                e = ast_for_genexp(c, ch);
+                if (!e)
+                    return NULL;
+                asdl_seq_SET(args, nargs++, e);
+            }
+            else {
+                keyword_ty kw;
+                identifier key;
+
+                /* CHILD(ch, 0) is test, but must be an identifier? */ 
+                e = ast_for_expr(c, CHILD(ch, 0));
+                if (!e)
+                    return NULL;
+                /* f(lambda x: x[0] = 3) ends up getting parsed with
+                 * LHS test = lambda x: x[0], and RHS test = 3.
+                 * SF bug 132313 points out that complaining about a keyword
+                 * then is very confusing.
+                 */
+                if (e->kind == Lambda_kind) {
+                    ast_error(CHILD(ch, 0),
+                              "lambda cannot contain assignment");
+                    return NULL;
+                } else if (e->kind != Name_kind) {
+                    ast_error(CHILD(ch, 0), "keyword can't be an expression");
+                    return NULL;
+                }
+                key = e->v.Name.id;
+                e = ast_for_expr(c, CHILD(ch, 2));
+                if (!e)
+                    return NULL;
+                kw = keyword(key, e, c->c_arena);
+                if (!kw)
+                    return NULL;
+                asdl_seq_SET(keywords, nkeywords++, kw);
+            }
+        }
+        else if (TYPE(ch) == STAR) {
+            vararg = ast_for_expr(c, CHILD(n, i+1));
+            i++;
+        }
+        else if (TYPE(ch) == DOUBLESTAR) {
+            kwarg = ast_for_expr(c, CHILD(n, i+1));
+            i++;
+        }
+    }
+
+    return Call(func, args, keywords, vararg, kwarg, func->lineno,
+                func->col_offset, c->c_arena);
 }
 
 static expr_ty
@@ -1892,21 +1895,21 @@ ast_for_testlist(struct compiling *c, const node* n)
     /* testlist1: test (',' test)* */
     assert(NCH(n) > 0);
     if (TYPE(n) == testlist_gexp) {
-	if (NCH(n) > 1)
-	    assert(TYPE(CHILD(n, 1)) != gen_for);
+        if (NCH(n) > 1)
+            assert(TYPE(CHILD(n, 1)) != gen_for);
     }
     else {
-	assert(TYPE(n) == testlist ||
-	       TYPE(n) == testlist_safe ||
-	       TYPE(n) == testlist1);
+        assert(TYPE(n) == testlist ||
+               TYPE(n) == testlist_safe ||
+               TYPE(n) == testlist1);
     }
     if (NCH(n) == 1)
-	return ast_for_expr(c, CHILD(n, 0));
+        return ast_for_expr(c, CHILD(n, 0));
     else {
-	asdl_seq *tmp = seq_for_testlist(c, n);
-	if (!tmp)
-	    return NULL;
-	return Tuple(tmp, Load, LINENO(n), n->n_col_offset, c->c_arena);
+        asdl_seq *tmp = seq_for_testlist(c, n);
+        if (!tmp)
+            return NULL;
+        return Tuple(tmp, Load, LINENO(n), n->n_col_offset, c->c_arena);
     }
 }
 
@@ -1917,7 +1920,7 @@ ast_for_testlist_gexp(struct compiling *c, const node* n)
     /* argument: test [ gen_for ] */
     assert(TYPE(n) == testlist_gexp || TYPE(n) == argument);
     if (NCH(n) > 1 && TYPE(CHILD(n, 1)) == gen_for)
-	return ast_for_genexp(c, n);
+        return ast_for_genexp(c, n);
     return ast_for_testlist(c, n);
 }
 
@@ -1929,15 +1932,15 @@ ast_for_class_bases(struct compiling *c, const node* n)
     assert(NCH(n) > 0);
     REQ(n, testlist);
     if (NCH(n) == 1) {
-	expr_ty base;
-	asdl_seq *bases = asdl_seq_new(1, c->c_arena);
-	if (!bases)
-	    return NULL;
-	base = ast_for_expr(c, CHILD(n, 0));
-	if (!base)
-	    return NULL;
-	asdl_seq_SET(bases, 0, base);
-	return bases;
+        expr_ty base;
+        asdl_seq *bases = asdl_seq_new(1, c->c_arena);
+        if (!bases)
+            return NULL;
+        base = ast_for_expr(c, CHILD(n, 0));
+        if (!base)
+            return NULL;
+        asdl_seq_SET(bases, 0, base);
+        return bases;
     }
 
     return seq_for_testlist(c, n);
@@ -1948,108 +1951,110 @@ ast_for_expr_stmt(struct compiling *c, const node *n)
 {
     REQ(n, expr_stmt);
     /* expr_stmt: testlist (augassign (yield_expr|testlist) 
-		| ('=' (yield_expr|testlist))*)
+                | ('=' (yield_expr|testlist))*)
        testlist: test (',' test)* [',']
        augassign: '+=' | '-=' | '*=' | '/=' | '%=' | '&=' | '|=' | '^='
-		| '<<=' | '>>=' | '**=' | '//='
+                | '<<=' | '>>=' | '**=' | '//='
        test: ... here starts the operator precendence dance
      */
 
     if (NCH(n) == 1) {
-	expr_ty e = ast_for_testlist(c, CHILD(n, 0));
-	if (!e)
-	    return NULL;
+        expr_ty e = ast_for_testlist(c, CHILD(n, 0));
+        if (!e)
+            return NULL;
 
-	return Expr(e, LINENO(n), n->n_col_offset, c->c_arena);
+        return Expr(e, LINENO(n), n->n_col_offset, c->c_arena);
     }
     else if (TYPE(CHILD(n, 1)) == augassign) {
-	expr_ty expr1, expr2;
-	operator_ty newoperator;
-	node *ch = CHILD(n, 0);
-
-	expr1 = ast_for_testlist(c, ch);
-	if (!expr1)
-	    return NULL;
-	/* TODO(nas): Remove duplicated error checks (set_context does it) */
-	switch (expr1->kind) {
-	    case GeneratorExp_kind:
-		ast_error(ch, "augmented assignment to generator "
-			  "expression not possible");
-		return NULL;
-	    case Yield_kind:
-		ast_error(ch, "augmented assignment to yield "
-			  "expression not possible");
-		return NULL;
-	    case Name_kind: {
-		const char *var_name = PyString_AS_STRING(expr1->v.Name.id);
-		if (var_name[0] == 'N' && !strcmp(var_name, "None")) {
-		    ast_error(ch, "assignment to None");
-		    return NULL;
-		}
-		break;
-	    }
-	    case Attribute_kind:
-	    case Subscript_kind:
-		break;
-	    default:
-		ast_error(ch, "illegal expression for augmented "
-			  "assignment");
-		return NULL;
-	}
-	if(!set_context(expr1, Store, ch))
-		return NULL;
-
-	ch = CHILD(n, 2);
-	if (TYPE(ch) == testlist)
-	    expr2 = ast_for_testlist(c, ch);
-	else
-	    expr2 = ast_for_expr(c, ch);
-	if (!expr2)
-	    return NULL;
-
-	newoperator = ast_for_augassign(CHILD(n, 1));
-	if (!newoperator)
-	    return NULL;
-
-	return AugAssign(expr1, newoperator, expr2, LINENO(n), n->n_col_offset, c->c_arena);
+        expr_ty expr1, expr2;
+        operator_ty newoperator;
+        node *ch = CHILD(n, 0);
+
+        expr1 = ast_for_testlist(c, ch);
+        if (!expr1)
+            return NULL;
+        /* TODO(nas): Remove duplicated error checks (set_context does it) */
+        switch (expr1->kind) {
+            case GeneratorExp_kind:
+                ast_error(ch, "augmented assignment to generator "
+                          "expression not possible");
+                return NULL;
+            case Yield_kind:
+                ast_error(ch, "augmented assignment to yield "
+                          "expression not possible");
+                return NULL;
+            case Name_kind: {
+                const char *var_name = PyString_AS_STRING(expr1->v.Name.id);
+                if (var_name[0] == 'N' && !strcmp(var_name, "None")) {
+                    ast_error(ch, "assignment to None");
+                    return NULL;
+                }
+                break;
+            }
+            case Attribute_kind:
+            case Subscript_kind:
+                break;
+            default:
+                ast_error(ch, "illegal expression for augmented "
+                          "assignment");
+                return NULL;
+        }
+        if(!set_context(expr1, Store, ch))
+            return NULL;
+
+        ch = CHILD(n, 2);
+        if (TYPE(ch) == testlist)
+            expr2 = ast_for_testlist(c, ch);
+        else
+            expr2 = ast_for_expr(c, ch);
+        if (!expr2)
+            return NULL;
+
+        newoperator = ast_for_augassign(CHILD(n, 1));
+        if (!newoperator)
+            return NULL;
+
+        return AugAssign(expr1, newoperator, expr2, LINENO(n), n->n_col_offset,
+                         c->c_arena);
     }
     else {
-	int i;
-	asdl_seq *targets;
-	node *value;
-	expr_ty expression;
-
-	/* a normal assignment */
-	REQ(CHILD(n, 1), EQUAL);
-	targets = asdl_seq_new(NCH(n) / 2, c->c_arena);
-	if (!targets)
-	    return NULL;
-	for (i = 0; i < NCH(n) - 2; i += 2) {
-	    expr_ty e;
-	    node *ch = CHILD(n, i);
-	    if (TYPE(ch) == yield_expr) {
-		ast_error(ch, "assignment to yield expression not possible");
-		return NULL;
-	    }
-	    e = ast_for_testlist(c, ch);
-
-	    /* set context to assign */
-	    if (!e) 
-	      return NULL;
-
-	    if (!set_context(e, Store, CHILD(n, i)))
-	      return NULL;
-
-	    asdl_seq_SET(targets, i / 2, e);
-	}
-	value = CHILD(n, NCH(n) - 1);
-	if (TYPE(value) == testlist)
-	    expression = ast_for_testlist(c, value);
-	else
-	    expression = ast_for_expr(c, value);
-	if (!expression)
-	    return NULL;
-	return Assign(targets, expression, LINENO(n), n->n_col_offset, c->c_arena);
+        int i;
+        asdl_seq *targets;
+        node *value;
+        expr_ty expression;
+
+        /* a normal assignment */
+        REQ(CHILD(n, 1), EQUAL);
+        targets = asdl_seq_new(NCH(n) / 2, c->c_arena);
+        if (!targets)
+            return NULL;
+        for (i = 0; i < NCH(n) - 2; i += 2) {
+            expr_ty e;
+            node *ch = CHILD(n, i);
+            if (TYPE(ch) == yield_expr) {
+                ast_error(ch, "assignment to yield expression not possible");
+                return NULL;
+            }
+            e = ast_for_testlist(c, ch);
+
+            /* set context to assign */
+            if (!e) 
+                return NULL;
+
+            if (!set_context(e, Store, CHILD(n, i)))
+                return NULL;
+
+            asdl_seq_SET(targets, i / 2, e);
+        }
+        value = CHILD(n, NCH(n) - 1);
+        if (TYPE(value) == testlist)
+            expression = ast_for_testlist(c, value);
+        else
+            expression = ast_for_expr(c, value);
+        if (!expression)
+            return NULL;
+        return Assign(targets, expression, LINENO(n), n->n_col_offset,
+                      c->c_arena);
     }
 }
 
@@ -2057,7 +2062,7 @@ static stmt_ty
 ast_for_print_stmt(struct compiling *c, const node *n)
 {
     /* print_stmt: 'print' ( [ test (',' test)* [','] ]
-			     | '>>' test [ (',' test)+ [','] ] )
+                             | '>>' test [ (',' test)+ [','] ] )
      */
     expr_ty dest = NULL, expression;
     asdl_seq *seq;
@@ -2066,19 +2071,19 @@ ast_for_print_stmt(struct compiling *c, const node *n)
 
     REQ(n, print_stmt);
     if (NCH(n) >= 2 && TYPE(CHILD(n, 1)) == RIGHTSHIFT) {
-	dest = ast_for_expr(c, CHILD(n, 2));
-	if (!dest)
-	    return NULL;
-	    start = 4;
+        dest = ast_for_expr(c, CHILD(n, 2));
+        if (!dest)
+            return NULL;
+            start = 4;
     }
     seq = asdl_seq_new((NCH(n) + 1 - start) / 2, c->c_arena);
     if (!seq)
-	return NULL;
+        return NULL;
     for (i = start, j = 0; i < NCH(n); i += 2, ++j) {
-	expression = ast_for_expr(c, CHILD(n, i));
-	if (!expression)
-	    return NULL;
-	asdl_seq_SET(seq, j, expression);
+        expression = ast_for_expr(c, CHILD(n, i));
+        if (!expression)
+            return NULL;
+        asdl_seq_SET(seq, j, expression);
     }
     nl = (TYPE(CHILD(n, NCH(n) - 1)) == COMMA) ? false : true;
     return Print(dest, seq, nl, LINENO(n), n->n_col_offset, c->c_arena);
@@ -2095,14 +2100,14 @@ ast_for_exprlist(struct compiling *c, const node *n, expr_context_ty context)
 
     seq = asdl_seq_new((NCH(n) + 1) / 2, c->c_arena);
     if (!seq)
-	return NULL;
+        return NULL;
     for (i = 0; i < NCH(n); i += 2) {
-	e = ast_for_expr(c, CHILD(n, i));
-	if (!e)
-	    return NULL;
-	asdl_seq_SET(seq, i / 2, e);
-	if (context && !set_context(e, context, CHILD(n, i)))
-	    return NULL;
+        e = ast_for_expr(c, CHILD(n, i));
+        if (!e)
+            return NULL;
+        asdl_seq_SET(seq, i / 2, e);
+        if (context && !set_context(e, context, CHILD(n, i)))
+            return NULL;
     }
     return seq;
 }
@@ -2117,7 +2122,7 @@ ast_for_del_stmt(struct compiling *c, const node *n)
 
     expr_list = ast_for_exprlist(c, CHILD(n, 1), Del);
     if (!expr_list)
-	return NULL;
+        return NULL;
     return Delete(expr_list, LINENO(n), n->n_col_offset, c->c_arena);
 }
 
@@ -2126,7 +2131,7 @@ ast_for_flow_stmt(struct compiling *c, const node *n)
 {
     /*
       flow_stmt: break_stmt | continue_stmt | return_stmt | raise_stmt
-		 | yield_stmt
+                 | yield_stmt
       break_stmt: 'break'
       continue_stmt: 'continue'
       return_stmt: 'return' [testlist]
@@ -2139,65 +2144,70 @@ ast_for_flow_stmt(struct compiling *c, const node *n)
     REQ(n, flow_stmt);
     ch = CHILD(n, 0);
     switch (TYPE(ch)) {
-	case break_stmt:
-	    return Break(LINENO(n), n->n_col_offset, c->c_arena);
-	case continue_stmt:
-	    return Continue(LINENO(n), n->n_col_offset, c->c_arena);
-	case yield_stmt: { /* will reduce to yield_expr */
-	    expr_ty exp = ast_for_expr(c, CHILD(ch, 0));
-	    if (!exp)
-		return NULL;
-	    return Expr(exp, LINENO(n), n->n_col_offset, c->c_arena);
-	}
-	case return_stmt:
-	    if (NCH(ch) == 1)
-		return Return(NULL, LINENO(n), n->n_col_offset, c->c_arena);
-	    else {
-		expr_ty expression = ast_for_testlist(c, CHILD(ch, 1));
-		if (!expression)
-		    return NULL;
-		return Return(expression, LINENO(n), n->n_col_offset, c->c_arena);
-	    }
-	case raise_stmt:
-	    if (NCH(ch) == 1)
-		return Raise(NULL, NULL, NULL, LINENO(n), n->n_col_offset, c->c_arena);
-	    else if (NCH(ch) == 2) {
-		expr_ty expression = ast_for_expr(c, CHILD(ch, 1));
-		if (!expression)
-		    return NULL;
-		return Raise(expression, NULL, NULL, LINENO(n), n->n_col_offset, c->c_arena);
-	    }
-	    else if (NCH(ch) == 4) {
-		expr_ty expr1, expr2;
-
-		expr1 = ast_for_expr(c, CHILD(ch, 1));
-		if (!expr1)
-		    return NULL;
-		expr2 = ast_for_expr(c, CHILD(ch, 3));
-		if (!expr2)
-		    return NULL;
-
-		return Raise(expr1, expr2, NULL, LINENO(n), n->n_col_offset, c->c_arena);
-	    }
-	    else if (NCH(ch) == 6) {
-		expr_ty expr1, expr2, expr3;
-
-		expr1 = ast_for_expr(c, CHILD(ch, 1));
-		if (!expr1)
-		    return NULL;
-		expr2 = ast_for_expr(c, CHILD(ch, 3));
-		if (!expr2)
-		    return NULL;
-		expr3 = ast_for_expr(c, CHILD(ch, 5));
-		if (!expr3)
-		    return NULL;
-		    
-		return Raise(expr1, expr2, expr3, LINENO(n), n->n_col_offset, c->c_arena);
-	    }
-	default:
-	    PyErr_Format(PyExc_SystemError,
-			 "unexpected flow_stmt: %d", TYPE(ch));
-	    return NULL;
+        case break_stmt:
+            return Break(LINENO(n), n->n_col_offset, c->c_arena);
+        case continue_stmt:
+            return Continue(LINENO(n), n->n_col_offset, c->c_arena);
+        case yield_stmt: { /* will reduce to yield_expr */
+            expr_ty exp = ast_for_expr(c, CHILD(ch, 0));
+            if (!exp)
+                return NULL;
+            return Expr(exp, LINENO(n), n->n_col_offset, c->c_arena);
+        }
+        case return_stmt:
+            if (NCH(ch) == 1)
+                return Return(NULL, LINENO(n), n->n_col_offset, c->c_arena);
+            else {
+                expr_ty expression = ast_for_testlist(c, CHILD(ch, 1));
+                if (!expression)
+                    return NULL;
+                return Return(expression, LINENO(n), n->n_col_offset,
+                              c->c_arena);
+            }
+        case raise_stmt:
+            if (NCH(ch) == 1)
+                return Raise(NULL, NULL, NULL, LINENO(n), n->n_col_offset,
+                             c->c_arena);
+            else if (NCH(ch) == 2) {
+                expr_ty expression = ast_for_expr(c, CHILD(ch, 1));
+                if (!expression)
+                    return NULL;
+                return Raise(expression, NULL, NULL, LINENO(n),
+                             n->n_col_offset, c->c_arena);
+            }
+            else if (NCH(ch) == 4) {
+                expr_ty expr1, expr2;
+
+                expr1 = ast_for_expr(c, CHILD(ch, 1));
+                if (!expr1)
+                    return NULL;
+                expr2 = ast_for_expr(c, CHILD(ch, 3));
+                if (!expr2)
+                    return NULL;
+
+                return Raise(expr1, expr2, NULL, LINENO(n), n->n_col_offset,
+                             c->c_arena);
+            }
+            else if (NCH(ch) == 6) {
+                expr_ty expr1, expr2, expr3;
+
+                expr1 = ast_for_expr(c, CHILD(ch, 1));
+                if (!expr1)
+                    return NULL;
+                expr2 = ast_for_expr(c, CHILD(ch, 3));
+                if (!expr2)
+                    return NULL;
+                expr3 = ast_for_expr(c, CHILD(ch, 5));
+                if (!expr3)
+                    return NULL;
+                    
+                return Raise(expr1, expr2, expr3, LINENO(n), n->n_col_offset,
+                             c->c_arena);
+            }
+        default:
+            PyErr_Format(PyExc_SystemError,
+                         "unexpected flow_stmt: %d", TYPE(ch));
+            return NULL;
     }
 
     PyErr_SetString(PyExc_SystemError, "unhandled flow statement");
@@ -2216,67 +2226,67 @@ alias_for_import_name(struct compiling *c, const node *n)
 
  loop:
     switch (TYPE(n)) {
-	case import_as_name:
-	    str = NULL;
-	    if (NCH(n) == 3) {
-		str = NEW_IDENTIFIER(CHILD(n, 2));
-	    }
-	    return alias(NEW_IDENTIFIER(CHILD(n, 0)), str, c->c_arena);
-	case dotted_as_name:
-	    if (NCH(n) == 1) {
-		n = CHILD(n, 0);
-		goto loop;
-	    }
-	    else {
-		alias_ty a = alias_for_import_name(c, CHILD(n, 0));
-		if (!a)
-		    return NULL;
-		assert(!a->asname);
-		a->asname = NEW_IDENTIFIER(CHILD(n, 2));
-		return a;
-	    }
-	    break;
-	case dotted_name:
-	    if (NCH(n) == 1)
-		return alias(NEW_IDENTIFIER(CHILD(n, 0)), NULL, c->c_arena);
-	    else {
-		/* Create a string of the form "a.b.c" */
-		int i;
-		size_t len;
-		char *s;
-
-		len = 0;
-		for (i = 0; i < NCH(n); i += 2)
-		    /* length of string plus one for the dot */
-		    len += strlen(STR(CHILD(n, i))) + 1;
-		len--; /* the last name doesn't have a dot */
-		str = PyString_FromStringAndSize(NULL, len);
-		if (!str)
-		    return NULL;
-		s = PyString_AS_STRING(str);
-		if (!s)
-		    return NULL;
-		for (i = 0; i < NCH(n); i += 2) {
-		    char *sch = STR(CHILD(n, i));
-		    strcpy(s, STR(CHILD(n, i)));
-		    s += strlen(sch);
-		    *s++ = '.';
-		}
-		--s;
-		*s = '\0';
-		PyString_InternInPlace(&str);
-		PyArena_AddPyObject(c->c_arena, str);
-		return alias(str, NULL, c->c_arena);
-	    }
-	    break;
-	case STAR:
-	    str = PyString_InternFromString("*");
-	    PyArena_AddPyObject(c->c_arena, str);
-	    return alias(str, NULL, c->c_arena);
-	default:
-	    PyErr_Format(PyExc_SystemError,
-			 "unexpected import name: %d", TYPE(n));
-	    return NULL;
+        case import_as_name:
+            str = NULL;
+            if (NCH(n) == 3) {
+                str = NEW_IDENTIFIER(CHILD(n, 2));
+            }
+            return alias(NEW_IDENTIFIER(CHILD(n, 0)), str, c->c_arena);
+        case dotted_as_name:
+            if (NCH(n) == 1) {
+                n = CHILD(n, 0);
+                goto loop;
+            }
+            else {
+                alias_ty a = alias_for_import_name(c, CHILD(n, 0));
+                if (!a)
+                    return NULL;
+                assert(!a->asname);
+                a->asname = NEW_IDENTIFIER(CHILD(n, 2));
+                return a;
+            }
+            break;
+        case dotted_name:
+            if (NCH(n) == 1)
+                return alias(NEW_IDENTIFIER(CHILD(n, 0)), NULL, c->c_arena);
+            else {
+                /* Create a string of the form "a.b.c" */
+                int i;
+                size_t len;
+                char *s;
+
+                len = 0;
+                for (i = 0; i < NCH(n); i += 2)
+                    /* length of string plus one for the dot */
+                    len += strlen(STR(CHILD(n, i))) + 1;
+                len--; /* the last name doesn't have a dot */
+                str = PyString_FromStringAndSize(NULL, len);
+                if (!str)
+                    return NULL;
+                s = PyString_AS_STRING(str);
+                if (!s)
+                    return NULL;
+                for (i = 0; i < NCH(n); i += 2) {
+                    char *sch = STR(CHILD(n, i));
+                    strcpy(s, STR(CHILD(n, i)));
+                    s += strlen(sch);
+                    *s++ = '.';
+                }
+                --s;
+                *s = '\0';
+                PyString_InternInPlace(&str);
+                PyArena_AddPyObject(c->c_arena, str);
+                return alias(str, NULL, c->c_arena);
+            }
+            break;
+        case STAR:
+            str = PyString_InternFromString("*");
+            PyArena_AddPyObject(c->c_arena, str);
+            return alias(str, NULL, c->c_arena);
+        default:
+            PyErr_Format(PyExc_SystemError,
+                         "unexpected import name: %d", TYPE(n));
+            return NULL;
     }
 
     PyErr_SetString(PyExc_SystemError, "unhandled import name condition");
@@ -2290,7 +2300,7 @@ ast_for_import_stmt(struct compiling *c, const node *n)
       import_stmt: import_name | import_from
       import_name: 'import' dotted_as_names
       import_from: 'from' ('.'* dotted_name | '.') 'import'
-			  ('*' | '(' import_as_names ')' | import_as_names)
+                          ('*' | '(' import_as_names ')' | import_as_names)
     */
     int lineno;
     int col_offset;
@@ -2302,97 +2312,97 @@ ast_for_import_stmt(struct compiling *c, const node *n)
     col_offset = n->n_col_offset;
     n = CHILD(n, 0);
     if (TYPE(n) == import_name) {
-	n = CHILD(n, 1);
-	REQ(n, dotted_as_names);
-	aliases = asdl_seq_new((NCH(n) + 1) / 2, c->c_arena);
-	if (!aliases)
-		return NULL;
-	for (i = 0; i < NCH(n); i += 2) {
-	    alias_ty import_alias = alias_for_import_name(c, CHILD(n, i));
-	    if (!import_alias)
-		return NULL;
-	    asdl_seq_SET(aliases, i / 2, import_alias);
-	}
-	return Import(aliases, lineno, col_offset, c->c_arena);
+        n = CHILD(n, 1);
+        REQ(n, dotted_as_names);
+        aliases = asdl_seq_new((NCH(n) + 1) / 2, c->c_arena);
+        if (!aliases)
+            return NULL;
+        for (i = 0; i < NCH(n); i += 2) {
+            alias_ty import_alias = alias_for_import_name(c, CHILD(n, i));
+            if (!import_alias)
+                return NULL;
+            asdl_seq_SET(aliases, i / 2, import_alias);
+        }
+        return Import(aliases, lineno, col_offset, c->c_arena);
     }
     else if (TYPE(n) == import_from) {
-	int n_children;
-	int idx, ndots = 0;
-	alias_ty mod = NULL;
-	identifier modname;
-	
+        int n_children;
+        int idx, ndots = 0;
+        alias_ty mod = NULL;
+        identifier modname;
+        
        /* Count the number of dots (for relative imports) and check for the
-	  optional module name */
-	for (idx = 1; idx < NCH(n); idx++) {
-	    if (TYPE(CHILD(n, idx)) == dotted_name) {
-		mod = alias_for_import_name(c, CHILD(n, idx));
-		idx++;
-		break;
-	    } else if (TYPE(CHILD(n, idx)) != DOT) {
-		break;
-	    }
-	    ndots++;
-	}
-	idx++; /* skip over the 'import' keyword */
-	switch (TYPE(CHILD(n, idx))) {
-	case STAR:
-	    /* from ... import * */
-	    n = CHILD(n, idx);
-	    n_children = 1;
-	    if (ndots) {
-		ast_error(n, "'import *' not allowed with 'from .'");
-		return NULL;
-	    }
-	    break;
-	case LPAR:
-	    /* from ... import (x, y, z) */
-	    n = CHILD(n, idx + 1);
-	    n_children = NCH(n);
-	    break;
-	case import_as_names:
-	    /* from ... import x, y, z */
-	    n = CHILD(n, idx);
-	    n_children = NCH(n);
-	    if (n_children % 2 == 0) {
-		ast_error(n, "trailing comma not allowed without"
-			     " surrounding parentheses");
-		return NULL;
-	    }
-	    break;
-	default:
-	    ast_error(n, "Unexpected node-type in from-import");
-	    return NULL;
-	}
-
-	aliases = asdl_seq_new((n_children + 1) / 2, c->c_arena);
-	if (!aliases)
-	    return NULL;
-
-	/* handle "from ... import *" special b/c there's no children */
-	if (TYPE(n) == STAR) {
-	    alias_ty import_alias = alias_for_import_name(c, n);
-	    if (!import_alias)
-		return NULL;
-		asdl_seq_SET(aliases, 0, import_alias);
-	}
-	else {
-	    for (i = 0; i < NCH(n); i += 2) {
-		alias_ty import_alias = alias_for_import_name(c, CHILD(n, i));
-		if (!import_alias)
-		    return NULL;
-		    asdl_seq_SET(aliases, i / 2, import_alias);
-	    }
-	}
-	if (mod != NULL)
-	    modname = mod->name;
-	else
-	    modname = new_identifier("", c->c_arena);
-	return ImportFrom(modname, aliases, ndots, lineno, col_offset,
-			  c->c_arena);
+          optional module name */
+        for (idx = 1; idx < NCH(n); idx++) {
+            if (TYPE(CHILD(n, idx)) == dotted_name) {
+                mod = alias_for_import_name(c, CHILD(n, idx));
+                idx++;
+                break;
+            } else if (TYPE(CHILD(n, idx)) != DOT) {
+                break;
+            }
+            ndots++;
+        }
+        idx++; /* skip over the 'import' keyword */
+        switch (TYPE(CHILD(n, idx))) {
+        case STAR:
+            /* from ... import * */
+            n = CHILD(n, idx);
+            n_children = 1;
+            if (ndots) {
+                ast_error(n, "'import *' not allowed with 'from .'");
+                return NULL;
+            }
+            break;
+        case LPAR:
+            /* from ... import (x, y, z) */
+            n = CHILD(n, idx + 1);
+            n_children = NCH(n);
+            break;
+        case import_as_names:
+            /* from ... import x, y, z */
+            n = CHILD(n, idx);
+            n_children = NCH(n);
+            if (n_children % 2 == 0) {
+                ast_error(n, "trailing comma not allowed without"
+                             " surrounding parentheses");
+                return NULL;
+            }
+            break;
+        default:
+            ast_error(n, "Unexpected node-type in from-import");
+            return NULL;
+        }
+
+        aliases = asdl_seq_new((n_children + 1) / 2, c->c_arena);
+        if (!aliases)
+            return NULL;
+
+        /* handle "from ... import *" special b/c there's no children */
+        if (TYPE(n) == STAR) {
+            alias_ty import_alias = alias_for_import_name(c, n);
+            if (!import_alias)
+                return NULL;
+                asdl_seq_SET(aliases, 0, import_alias);
+        }
+        else {
+            for (i = 0; i < NCH(n); i += 2) {
+                alias_ty import_alias = alias_for_import_name(c, CHILD(n, i));
+                if (!import_alias)
+                    return NULL;
+                    asdl_seq_SET(aliases, i / 2, import_alias);
+            }
+        }
+        if (mod != NULL)
+            modname = mod->name;
+        else
+            modname = new_identifier("", c->c_arena);
+        return ImportFrom(modname, aliases, ndots, lineno, col_offset,
+                          c->c_arena);
     }
     PyErr_Format(PyExc_SystemError,
-		 "unknown import statement: starts with command '%s'",
-		 STR(CHILD(n, 0)));
+                 "unknown import statement: starts with command '%s'",
+                 STR(CHILD(n, 0)));
     return NULL;
 }
 
@@ -2407,12 +2417,12 @@ ast_for_global_stmt(struct compiling *c, const node *n)
     REQ(n, global_stmt);
     s = asdl_seq_new(NCH(n) / 2, c->c_arena);
     if (!s)
-	return NULL;
+        return NULL;
     for (i = 1; i < NCH(n); i += 2) {
-	name = NEW_IDENTIFIER(CHILD(n, i));
-	if (!name)
-	    return NULL;
-	asdl_seq_SET(s, i / 2, name);
+        name = NEW_IDENTIFIER(CHILD(n, i));
+        if (!name)
+            return NULL;
+        asdl_seq_SET(s, i / 2, name);
     }
     return Global(s, LINENO(n), n->n_col_offset, c->c_arena);
 }
@@ -2423,29 +2433,30 @@ ast_for_exec_stmt(struct compiling *c, const node *n)
     expr_ty expr1, globals = NULL, locals = NULL;
     int n_children = NCH(n);
     if (n_children != 2 && n_children != 4 && n_children != 6) {
-	PyErr_Format(PyExc_SystemError,
-		     "poorly formed 'exec' statement: %d parts to statement",
-		     n_children);
-	return NULL;
+        PyErr_Format(PyExc_SystemError,
+                     "poorly formed 'exec' statement: %d parts to statement",
+                     n_children);
+        return NULL;
     }
 
     /* exec_stmt: 'exec' expr ['in' test [',' test]] */
     REQ(n, exec_stmt);
     expr1 = ast_for_expr(c, CHILD(n, 1));
     if (!expr1)
-	return NULL;
+        return NULL;
     if (n_children >= 4) {
-	globals = ast_for_expr(c, CHILD(n, 3));
-	if (!globals)
-	    return NULL;
+        globals = ast_for_expr(c, CHILD(n, 3));
+        if (!globals)
+            return NULL;
     }
     if (n_children == 6) {
-	locals = ast_for_expr(c, CHILD(n, 5));
-	if (!locals)
-	    return NULL;
+        locals = ast_for_expr(c, CHILD(n, 5));
+        if (!locals)
+            return NULL;
     }
 
-    return Exec(expr1, globals, locals, LINENO(n), n->n_col_offset, c->c_arena);
+    return Exec(expr1, globals, locals, LINENO(n), n->n_col_offset,
+                c->c_arena);
 }
 
 static stmt_ty
@@ -2454,26 +2465,27 @@ ast_for_assert_stmt(struct compiling *c, const node *n)
     /* assert_stmt: 'assert' test [',' test] */
     REQ(n, assert_stmt);
     if (NCH(n) == 2) {
-	expr_ty expression = ast_for_expr(c, CHILD(n, 1));
-	if (!expression)
-	    return NULL;
-	return Assert(expression, NULL, LINENO(n), n->n_col_offset, c->c_arena);
+        expr_ty expression = ast_for_expr(c, CHILD(n, 1));
+        if (!expression)
+            return NULL;
+        return Assert(expression, NULL, LINENO(n), n->n_col_offset,
+                      c->c_arena);
     }
     else if (NCH(n) == 4) {
-	expr_ty expr1, expr2;
-
-	expr1 = ast_for_expr(c, CHILD(n, 1));
-	if (!expr1)
-	    return NULL;
-	expr2 = ast_for_expr(c, CHILD(n, 3));
-	if (!expr2)
-	    return NULL;
-	    
-	return Assert(expr1, expr2, LINENO(n), n->n_col_offset, c->c_arena);
+        expr_ty expr1, expr2;
+
+        expr1 = ast_for_expr(c, CHILD(n, 1));
+        if (!expr1)
+            return NULL;
+        expr2 = ast_for_expr(c, CHILD(n, 3));
+        if (!expr2)
+            return NULL;
+            
+        return Assert(expr1, expr2, LINENO(n), n->n_col_offset, c->c_arena);
     }
     PyErr_Format(PyExc_SystemError,
-		 "improper number of parts to 'assert' statement: %d",
-		 NCH(n));
+                 "improper number of parts to 'assert' statement: %d",
+                 NCH(n));
     return NULL;
 }
 
@@ -2491,53 +2503,53 @@ ast_for_suite(struct compiling *c, const node *n)
     total = num_stmts(n);
     seq = asdl_seq_new(total, c->c_arena);
     if (!seq)
-	return NULL;
+        return NULL;
     if (TYPE(CHILD(n, 0)) == simple_stmt) {
-	n = CHILD(n, 0);
-	/* simple_stmt always ends with a NEWLINE,
-	   and may have a trailing SEMI 
-	*/
-	end = NCH(n) - 1;
-	if (TYPE(CHILD(n, end - 1)) == SEMI)
-	    end--;
-	/* loop by 2 to skip semi-colons */
-	for (i = 0; i < end; i += 2) {
-	    ch = CHILD(n, i);
-	    s = ast_for_stmt(c, ch);
-	    if (!s)
-		return NULL;
-	    asdl_seq_SET(seq, pos++, s);
-	}
+        n = CHILD(n, 0);
+        /* simple_stmt always ends with a NEWLINE,
+           and may have a trailing SEMI 
+        */
+        end = NCH(n) - 1;
+        if (TYPE(CHILD(n, end - 1)) == SEMI)
+            end--;
+        /* loop by 2 to skip semi-colons */
+        for (i = 0; i < end; i += 2) {
+            ch = CHILD(n, i);
+            s = ast_for_stmt(c, ch);
+            if (!s)
+                return NULL;
+            asdl_seq_SET(seq, pos++, s);
+        }
     }
     else {
-	for (i = 2; i < (NCH(n) - 1); i++) {
-	    ch = CHILD(n, i);
-	    REQ(ch, stmt);
-	    num = num_stmts(ch);
-	    if (num == 1) {
-		/* small_stmt or compound_stmt with only one child */
-		s = ast_for_stmt(c, ch);
-		if (!s)
-		    return NULL;
-		asdl_seq_SET(seq, pos++, s);
-	    }
-	    else {
-		int j;
-		ch = CHILD(ch, 0);
-		REQ(ch, simple_stmt);
-		for (j = 0; j < NCH(ch); j += 2) {
-		    /* statement terminates with a semi-colon ';' */
-		    if (NCH(CHILD(ch, j)) == 0) {
-			assert((j + 1) == NCH(ch));
-			break;
-		    }
-		    s = ast_for_stmt(c, CHILD(ch, j));
-		    if (!s)
-			return NULL;
-		    asdl_seq_SET(seq, pos++, s);
-		}
-	    }
-	}
+        for (i = 2; i < (NCH(n) - 1); i++) {
+            ch = CHILD(n, i);
+            REQ(ch, stmt);
+            num = num_stmts(ch);
+            if (num == 1) {
+                /* small_stmt or compound_stmt with only one child */
+                s = ast_for_stmt(c, ch);
+                if (!s)
+                    return NULL;
+                asdl_seq_SET(seq, pos++, s);
+            }
+            else {
+                int j;
+                ch = CHILD(ch, 0);
+                REQ(ch, simple_stmt);
+                for (j = 0; j < NCH(ch); j += 2) {
+                    /* statement terminates with a semi-colon ';' */
+                    if (NCH(CHILD(ch, j)) == 0) {
+                        assert((j + 1) == NCH(ch));
+                        break;
+                    }
+                    s = ast_for_stmt(c, CHILD(ch, j));
+                    if (!s)
+                        return NULL;
+                    asdl_seq_SET(seq, pos++, s);
+                }
+            }
+        }
     }
     assert(pos == seq->size);
     return seq;
@@ -2554,17 +2566,18 @@ ast_for_if_stmt(struct compiling *c, const node *n)
     REQ(n, if_stmt);
 
     if (NCH(n) == 4) {
-	expr_ty expression;
-	asdl_seq *suite_seq;
-
-	expression = ast_for_expr(c, CHILD(n, 1));
-	if (!expression)
-	    return NULL;
-	suite_seq = ast_for_suite(c, CHILD(n, 3)); 
-	if (!suite_seq)
-	    return NULL;
-	    
-	return If(expression, suite_seq, NULL, LINENO(n), n->n_col_offset, c->c_arena);
+        expr_ty expression;
+        asdl_seq *suite_seq;
+
+        expression = ast_for_expr(c, CHILD(n, 1));
+        if (!expression)
+            return NULL;
+        suite_seq = ast_for_suite(c, CHILD(n, 3)); 
+        if (!suite_seq)
+            return NULL;
+            
+        return If(expression, suite_seq, NULL, LINENO(n), n->n_col_offset,
+                  c->c_arena);
     }
 
     s = STR(CHILD(n, 4));
@@ -2573,88 +2586,92 @@ ast_for_if_stmt(struct compiling *c, const node *n)
        'i' for el_i_f
     */
     if (s[2] == 's') {
-	expr_ty expression;
-	asdl_seq *seq1, *seq2;
-
-	expression = ast_for_expr(c, CHILD(n, 1));
-	if (!expression)
-	    return NULL;
-	seq1 = ast_for_suite(c, CHILD(n, 3));
-	if (!seq1)
-	    return NULL;
-	seq2 = ast_for_suite(c, CHILD(n, 6));
-	if (!seq2)
-	    return NULL;
-
-	return If(expression, seq1, seq2, LINENO(n), n->n_col_offset, c->c_arena);
+        expr_ty expression;
+        asdl_seq *seq1, *seq2;
+
+        expression = ast_for_expr(c, CHILD(n, 1));
+        if (!expression)
+            return NULL;
+        seq1 = ast_for_suite(c, CHILD(n, 3));
+        if (!seq1)
+            return NULL;
+        seq2 = ast_for_suite(c, CHILD(n, 6));
+        if (!seq2)
+            return NULL;
+
+        return If(expression, seq1, seq2, LINENO(n), n->n_col_offset,
+                  c->c_arena);
     }
     else if (s[2] == 'i') {
-	int i, n_elif, has_else = 0;
-	expr_ty expression;
-	asdl_seq *suite_seq;
-	asdl_seq *orelse = NULL;
-	n_elif = NCH(n) - 4;
-	/* must reference the child n_elif+1 since 'else' token is third,
-	   not fourth, child from the end. */
-	if (TYPE(CHILD(n, (n_elif + 1))) == NAME
-	    && STR(CHILD(n, (n_elif + 1)))[2] == 's') {
-	    has_else = 1;
-	    n_elif -= 3;
-	}
-	n_elif /= 4;
-
-	if (has_else) {
-	    asdl_seq *suite_seq2;
-
-	    orelse = asdl_seq_new(1, c->c_arena);
-	    if (!orelse)
-		return NULL;
-	    expression = ast_for_expr(c, CHILD(n, NCH(n) - 6));
-	    if (!expression)
-		return NULL;
-	    suite_seq = ast_for_suite(c, CHILD(n, NCH(n) - 4));
-	    if (!suite_seq)
-		return NULL;
-	    suite_seq2 = ast_for_suite(c, CHILD(n, NCH(n) - 1));
-	    if (!suite_seq2)
-		return NULL;
-
-	    asdl_seq_SET(orelse, 0, If(expression, suite_seq, suite_seq2, 
-				       LINENO(CHILD(n, NCH(n) - 6)), CHILD(n, NCH(n) - 6)->n_col_offset,
-				       c->c_arena));
-	    /* the just-created orelse handled the last elif */
-	    n_elif--;
-	}
-
-	for (i = 0; i < n_elif; i++) {
-	    int off = 5 + (n_elif - i - 1) * 4;
-	    asdl_seq *newobj = asdl_seq_new(1, c->c_arena);
-	    if (!newobj)
-		return NULL;
-	    expression = ast_for_expr(c, CHILD(n, off));
-	    if (!expression)
-		return NULL;
-	    suite_seq = ast_for_suite(c, CHILD(n, off + 2));
-	    if (!suite_seq)
-		return NULL;
-
-	    asdl_seq_SET(newobj, 0,
-			 If(expression, suite_seq, orelse, 
-			    LINENO(CHILD(n, off)), CHILD(n, off)->n_col_offset, c->c_arena));
-	    orelse = newobj;
-	}
-	expression = ast_for_expr(c, CHILD(n, 1));
-	if (!expression)
-		return NULL;
-	suite_seq = ast_for_suite(c, CHILD(n, 3));
-	if (!suite_seq)
-		return NULL;
-	return If(expression, suite_seq, orelse,
-              LINENO(n), n->n_col_offset, c->c_arena);
+        int i, n_elif, has_else = 0;
+        expr_ty expression;
+        asdl_seq *suite_seq;
+        asdl_seq *orelse = NULL;
+        n_elif = NCH(n) - 4;
+        /* must reference the child n_elif+1 since 'else' token is third,
+           not fourth, child from the end. */
+        if (TYPE(CHILD(n, (n_elif + 1))) == NAME
+            && STR(CHILD(n, (n_elif + 1)))[2] == 's') {
+            has_else = 1;
+            n_elif -= 3;
+        }
+        n_elif /= 4;
+
+        if (has_else) {
+            asdl_seq *suite_seq2;
+
+            orelse = asdl_seq_new(1, c->c_arena);
+            if (!orelse)
+                return NULL;
+            expression = ast_for_expr(c, CHILD(n, NCH(n) - 6));
+            if (!expression)
+                return NULL;
+            suite_seq = ast_for_suite(c, CHILD(n, NCH(n) - 4));
+            if (!suite_seq)
+                return NULL;
+            suite_seq2 = ast_for_suite(c, CHILD(n, NCH(n) - 1));
+            if (!suite_seq2)
+                return NULL;
+
+            asdl_seq_SET(orelse, 0, 
+                         If(expression, suite_seq, suite_seq2, 
+                            LINENO(CHILD(n, NCH(n) - 6)),
+                            CHILD(n, NCH(n) - 6)->n_col_offset,
+                            c->c_arena));
+            /* the just-created orelse handled the last elif */
+            n_elif--;
+        }
+
+        for (i = 0; i < n_elif; i++) {
+            int off = 5 + (n_elif - i - 1) * 4;
+            asdl_seq *newobj = asdl_seq_new(1, c->c_arena);
+            if (!newobj)
+                return NULL;
+            expression = ast_for_expr(c, CHILD(n, off));
+            if (!expression)
+                return NULL;
+            suite_seq = ast_for_suite(c, CHILD(n, off + 2));
+            if (!suite_seq)
+                return NULL;
+
+            asdl_seq_SET(newobj, 0,
+                         If(expression, suite_seq, orelse, 
+                            LINENO(CHILD(n, off)),
+                            CHILD(n, off)->n_col_offset, c->c_arena));
+            orelse = newobj;
+        }
+        expression = ast_for_expr(c, CHILD(n, 1));
+        if (!expression)
+            return NULL;
+        suite_seq = ast_for_suite(c, CHILD(n, 3));
+        if (!suite_seq)
+            return NULL;
+        return If(expression, suite_seq, orelse,
+                  LINENO(n), n->n_col_offset, c->c_arena);
     }
 
     PyErr_Format(PyExc_SystemError,
-		 "unexpected token in 'if' statement: %s", s);
+                 "unexpected token in 'if' statement: %s", s);
     return NULL;
 }
 
@@ -2665,37 +2682,39 @@ ast_for_while_stmt(struct compiling *c, const node *n)
     REQ(n, while_stmt);
 
     if (NCH(n) == 4) {
-	expr_ty expression;
-	asdl_seq *suite_seq;
-
-	expression = ast_for_expr(c, CHILD(n, 1));
-	if (!expression)
-	    return NULL;
-	suite_seq = ast_for_suite(c, CHILD(n, 3));
-	if (!suite_seq)
-	    return NULL;
-	return While(expression, suite_seq, NULL, LINENO(n), n->n_col_offset, c->c_arena);
+        expr_ty expression;
+        asdl_seq *suite_seq;
+
+        expression = ast_for_expr(c, CHILD(n, 1));
+        if (!expression)
+            return NULL;
+        suite_seq = ast_for_suite(c, CHILD(n, 3));
+        if (!suite_seq)
+            return NULL;
+        return While(expression, suite_seq, NULL, LINENO(n), n->n_col_offset,
+                     c->c_arena);
     }
     else if (NCH(n) == 7) {
-	expr_ty expression;
-	asdl_seq *seq1, *seq2;
+        expr_ty expression;
+        asdl_seq *seq1, *seq2;
 
-	expression = ast_for_expr(c, CHILD(n, 1));
-	if (!expression)
-	    return NULL;
-	seq1 = ast_for_suite(c, CHILD(n, 3));
-	if (!seq1)
-	    return NULL;
-	seq2 = ast_for_suite(c, CHILD(n, 6));
-	if (!seq2)
-	    return NULL;
+        expression = ast_for_expr(c, CHILD(n, 1));
+        if (!expression)
+            return NULL;
+        seq1 = ast_for_suite(c, CHILD(n, 3));
+        if (!seq1)
+            return NULL;
+        seq2 = ast_for_suite(c, CHILD(n, 6));
+        if (!seq2)
+            return NULL;
 
-	return While(expression, seq1, seq2, LINENO(n), n->n_col_offset, c->c_arena);
+        return While(expression, seq1, seq2, LINENO(n), n->n_col_offset,
+                     c->c_arena);
     }
 
     PyErr_Format(PyExc_SystemError,
-		 "wrong number of tokens for 'while' statement: %d",
-		 NCH(n));
+                 "wrong number of tokens for 'while' statement: %d",
+                 NCH(n));
     return NULL;
 }
 
@@ -2710,31 +2729,31 @@ ast_for_for_stmt(struct compiling *c, const node *n)
     REQ(n, for_stmt);
 
     if (NCH(n) == 9) {
-	seq = ast_for_suite(c, CHILD(n, 8));
-	if (!seq)
-	    return NULL;
+        seq = ast_for_suite(c, CHILD(n, 8));
+        if (!seq)
+            return NULL;
     }
 
     node_target = CHILD(n, 1);
     _target = ast_for_exprlist(c, node_target, Store);
     if (!_target)
-	return NULL;
+        return NULL;
     /* Check the # of children rather than the length of _target, since
        for x, in ... has 1 element in _target, but still requires a Tuple. */
     if (NCH(node_target) == 1)
-	target = (expr_ty)asdl_seq_GET(_target, 0);
+        target = (expr_ty)asdl_seq_GET(_target, 0);
     else
-	target = Tuple(_target, Store, LINENO(n), n->n_col_offset, c->c_arena);
+        target = Tuple(_target, Store, LINENO(n), n->n_col_offset, c->c_arena);
 
     expression = ast_for_testlist(c, CHILD(n, 3));
     if (!expression)
-	return NULL;
+        return NULL;
     suite_seq = ast_for_suite(c, CHILD(n, 5));
     if (!suite_seq)
-	return NULL;
+        return NULL;
 
     return For(target, expression, suite_seq, seq, LINENO(n), n->n_col_offset,
-	       c->c_arena);
+               c->c_arena);
 }
 
 static excepthandler_ty
@@ -2745,49 +2764,49 @@ ast_for_except_clause(struct compiling *c, const node *exc, node *body)
     REQ(body, suite);
 
     if (NCH(exc) == 1) {
-	asdl_seq *suite_seq = ast_for_suite(c, body);
-	if (!suite_seq)
-	    return NULL;
+        asdl_seq *suite_seq = ast_for_suite(c, body);
+        if (!suite_seq)
+            return NULL;
 
-	return excepthandler(NULL, NULL, suite_seq, LINENO(exc),
-			     exc->n_col_offset, c->c_arena);
+        return excepthandler(NULL, NULL, suite_seq, LINENO(exc),
+                             exc->n_col_offset, c->c_arena);
     }
     else if (NCH(exc) == 2) {
-	expr_ty expression;
-	asdl_seq *suite_seq;
+        expr_ty expression;
+        asdl_seq *suite_seq;
 
-	expression = ast_for_expr(c, CHILD(exc, 1));
-	if (!expression)
-	    return NULL;
-	suite_seq = ast_for_suite(c, body);
-	if (!suite_seq)
-	    return NULL;
+        expression = ast_for_expr(c, CHILD(exc, 1));
+        if (!expression)
+            return NULL;
+        suite_seq = ast_for_suite(c, body);
+        if (!suite_seq)
+            return NULL;
 
-	return excepthandler(expression, NULL, suite_seq, LINENO(exc),
-			     exc->n_col_offset, c->c_arena);
+        return excepthandler(expression, NULL, suite_seq, LINENO(exc),
+                             exc->n_col_offset, c->c_arena);
     }
     else if (NCH(exc) == 4) {
-	asdl_seq *suite_seq;
-	expr_ty expression;
-	expr_ty e = ast_for_expr(c, CHILD(exc, 3));
-	if (!e)
-	    return NULL;
-	if (!set_context(e, Store, CHILD(exc, 3)))
-	    return NULL;
-	expression = ast_for_expr(c, CHILD(exc, 1));
-	if (!expression)
-	    return NULL;
-	suite_seq = ast_for_suite(c, body);
-	if (!suite_seq)
-	    return NULL;
-
-	return excepthandler(expression, e, suite_seq, LINENO(exc),
-			     exc->n_col_offset, c->c_arena);
+        asdl_seq *suite_seq;
+        expr_ty expression;
+        expr_ty e = ast_for_expr(c, CHILD(exc, 3));
+        if (!e)
+            return NULL;
+        if (!set_context(e, Store, CHILD(exc, 3)))
+            return NULL;
+        expression = ast_for_expr(c, CHILD(exc, 1));
+        if (!expression)
+            return NULL;
+        suite_seq = ast_for_suite(c, body);
+        if (!suite_seq)
+            return NULL;
+
+        return excepthandler(expression, e, suite_seq, LINENO(exc),
+                             exc->n_col_offset, c->c_arena);
     }
 
     PyErr_Format(PyExc_SystemError,
-		 "wrong number of children for 'except' clause: %d",
-		 NCH(exc));
+                 "wrong number of children for 'except' clause: %d",
+                 NCH(exc));
     return NULL;
 }
 
@@ -2802,66 +2821,66 @@ ast_for_try_stmt(struct compiling *c, const node *n)
 
     body = ast_for_suite(c, CHILD(n, 2));
     if (body == NULL)
-	return NULL;
+        return NULL;
 
     if (TYPE(CHILD(n, nch - 3)) == NAME) {
-	if (strcmp(STR(CHILD(n, nch - 3)), "finally") == 0) {
-	    if (nch >= 9 && TYPE(CHILD(n, nch - 6)) == NAME) {
-		/* we can assume it's an "else",
-		   because nch >= 9 for try-else-finally and
-		   it would otherwise have a type of except_clause */
-		orelse = ast_for_suite(c, CHILD(n, nch - 4));
-		if (orelse == NULL)
-		    return NULL;
-		n_except--;
-	    }
-
-	    finally = ast_for_suite(c, CHILD(n, nch - 1));
-	    if (finally == NULL)
-		return NULL;
-	    n_except--;
-	}
-	else {
-	    /* we can assume it's an "else",
-	       otherwise it would have a type of except_clause */
-	    orelse = ast_for_suite(c, CHILD(n, nch - 1));
-	    if (orelse == NULL)
-		return NULL;
-	    n_except--;
-	}
+        if (strcmp(STR(CHILD(n, nch - 3)), "finally") == 0) {
+            if (nch >= 9 && TYPE(CHILD(n, nch - 6)) == NAME) {
+                /* we can assume it's an "else",
+                   because nch >= 9 for try-else-finally and
+                   it would otherwise have a type of except_clause */
+                orelse = ast_for_suite(c, CHILD(n, nch - 4));
+                if (orelse == NULL)
+                    return NULL;
+                n_except--;
+            }
+
+            finally = ast_for_suite(c, CHILD(n, nch - 1));
+            if (finally == NULL)
+                return NULL;
+            n_except--;
+        }
+        else {
+            /* we can assume it's an "else",
+               otherwise it would have a type of except_clause */
+            orelse = ast_for_suite(c, CHILD(n, nch - 1));
+            if (orelse == NULL)
+                return NULL;
+            n_except--;
+        }
     }
     else if (TYPE(CHILD(n, nch - 3)) != except_clause) {
-	ast_error(n, "malformed 'try' statement");
-	return NULL;
+        ast_error(n, "malformed 'try' statement");
+        return NULL;
     }
     
     if (n_except > 0) {
-	int i;
-	stmt_ty except_st;
-	/* process except statements to create a try ... except */
-	asdl_seq *handlers = asdl_seq_new(n_except, c->c_arena);
-	if (handlers == NULL)
-	    return NULL;
-
-	for (i = 0; i < n_except; i++) {
-	    excepthandler_ty e = ast_for_except_clause(c, CHILD(n, 3 + i * 3),
-						       CHILD(n, 5 + i * 3));
-	    if (!e)
-		return NULL;
-	    asdl_seq_SET(handlers, i, e);
-	}
-
-	except_st = TryExcept(body, handlers, orelse, LINENO(n),
-			      n->n_col_offset, c->c_arena);
-	if (!finally)
-	    return except_st;
-
-	/* if a 'finally' is present too, we nest the TryExcept within a
-	   TryFinally to emulate try ... except ... finally */
-	body = asdl_seq_new(1, c->c_arena);
-	if (body == NULL)
-	    return NULL;
-	asdl_seq_SET(body, 0, except_st);
+        int i;
+        stmt_ty except_st;
+        /* process except statements to create a try ... except */
+        asdl_seq *handlers = asdl_seq_new(n_except, c->c_arena);
+        if (handlers == NULL)
+            return NULL;
+
+        for (i = 0; i < n_except; i++) {
+            excepthandler_ty e = ast_for_except_clause(c, CHILD(n, 3 + i * 3),
+                                                       CHILD(n, 5 + i * 3));
+            if (!e)
+                return NULL;
+            asdl_seq_SET(handlers, i, e);
+        }
+
+        except_st = TryExcept(body, handlers, orelse, LINENO(n),
+                              n->n_col_offset, c->c_arena);
+        if (!finally)
+            return except_st;
+
+        /* if a 'finally' is present too, we nest the TryExcept within a
+           TryFinally to emulate try ... except ... finally */
+        body = asdl_seq_new(1, c->c_arena);
+        if (body == NULL)
+            return NULL;
+        asdl_seq_SET(body, 0, except_st);
     }
 
     /* must be a try ... finally (except clauses are in body, if any exist) */
@@ -2889,23 +2908,23 @@ ast_for_with_stmt(struct compiling *c, const node *n)
     if (!context_expr)
         return NULL;
     if (TYPE(CHILD(n, 2)) == with_var) {
-	optional_vars = ast_for_with_var(c, CHILD(n, 2));
+        optional_vars = ast_for_with_var(c, CHILD(n, 2));
 
-	if (!optional_vars) {
-	    return NULL;
-	}
-	if (!set_context(optional_vars, Store, n)) {
-	    return NULL;
-	}
-	suite_index = 4;
+        if (!optional_vars) {
+            return NULL;
+        }
+        if (!set_context(optional_vars, Store, n)) {
+            return NULL;
+        }
+        suite_index = 4;
     }
 
     suite_seq = ast_for_suite(c, CHILD(n, suite_index));
     if (!suite_seq) {
-	return NULL;
+        return NULL;
     }
     return With(context_expr, optional_vars, suite_seq, LINENO(n), 
-		n->n_col_offset, c->c_arena);
+                n->n_col_offset, c->c_arena);
 }
 
 static stmt_ty
@@ -2917,246 +2936,246 @@ ast_for_classdef(struct compiling *c, const node *n)
     REQ(n, classdef);
 
     if (!strcmp(STR(CHILD(n, 1)), "None")) {
-	    ast_error(n, "assignment to None");
-	    return NULL;
+            ast_error(n, "assignment to None");
+            return NULL;
     }
 
     if (NCH(n) == 4) {
-	s = ast_for_suite(c, CHILD(n, 3));
-	if (!s)
-	    return NULL;
-	return ClassDef(NEW_IDENTIFIER(CHILD(n, 1)), NULL, s, LINENO(n),
-			n->n_col_offset, c->c_arena);
+        s = ast_for_suite(c, CHILD(n, 3));
+        if (!s)
+            return NULL;
+        return ClassDef(NEW_IDENTIFIER(CHILD(n, 1)), NULL, s, LINENO(n),
+                        n->n_col_offset, c->c_arena);
     }
     /* check for empty base list */
     if (TYPE(CHILD(n,3)) == RPAR) {
-	s = ast_for_suite(c, CHILD(n,5));
-	if (!s)
-		return NULL;
-	return ClassDef(NEW_IDENTIFIER(CHILD(n, 1)), NULL, s, LINENO(n),
-			n->n_col_offset, c->c_arena);
+        s = ast_for_suite(c, CHILD(n,5));
+        if (!s)
+                return NULL;
+        return ClassDef(NEW_IDENTIFIER(CHILD(n, 1)), NULL, s, LINENO(n),
+                        n->n_col_offset, c->c_arena);
     }
 
     /* else handle the base class list */
     bases = ast_for_class_bases(c, CHILD(n, 3));
     if (!bases)
-	return NULL;
+        return NULL;
 
     s = ast_for_suite(c, CHILD(n, 6));
     if (!s)
-	return NULL;
+        return NULL;
     return ClassDef(NEW_IDENTIFIER(CHILD(n, 1)), bases, s, LINENO(n),
-		    n->n_col_offset, c->c_arena);
+                    n->n_col_offset, c->c_arena);
 }
 
 static stmt_ty
 ast_for_stmt(struct compiling *c, const node *n)
 {
     if (TYPE(n) == stmt) {
-	assert(NCH(n) == 1);
-	n = CHILD(n, 0);
+        assert(NCH(n) == 1);
+        n = CHILD(n, 0);
     }
     if (TYPE(n) == simple_stmt) {
-	assert(num_stmts(n) == 1);
-	n = CHILD(n, 0);
+        assert(num_stmts(n) == 1);
+        n = CHILD(n, 0);
     }
     if (TYPE(n) == small_stmt) {
-	REQ(n, small_stmt);
-	n = CHILD(n, 0);
-	/* small_stmt: expr_stmt | print_stmt  | del_stmt | pass_stmt
-		     | flow_stmt | import_stmt | global_stmt | exec_stmt
-		     | assert_stmt
-	*/
-	switch (TYPE(n)) {
-	    case expr_stmt:
-		return ast_for_expr_stmt(c, n);
-	    case print_stmt:
-		return ast_for_print_stmt(c, n);
-	    case del_stmt:
-		return ast_for_del_stmt(c, n);
-	    case pass_stmt:
-		return Pass(LINENO(n), n->n_col_offset, c->c_arena);
-	    case flow_stmt:
-		return ast_for_flow_stmt(c, n);
-	    case import_stmt:
-		return ast_for_import_stmt(c, n);
-	    case global_stmt:
-		return ast_for_global_stmt(c, n);
-	    case exec_stmt:
-		return ast_for_exec_stmt(c, n);
-	    case assert_stmt:
-		return ast_for_assert_stmt(c, n);
-	    default:
-		PyErr_Format(PyExc_SystemError,
-			     "unhandled small_stmt: TYPE=%d NCH=%d\n",
-			     TYPE(n), NCH(n));
-		return NULL;
-	}
+        REQ(n, small_stmt);
+        n = CHILD(n, 0);
+        /* small_stmt: expr_stmt | print_stmt  | del_stmt | pass_stmt
+                     | flow_stmt | import_stmt | global_stmt | exec_stmt
+                     | assert_stmt
+        */
+        switch (TYPE(n)) {
+            case expr_stmt:
+                return ast_for_expr_stmt(c, n);
+            case print_stmt:
+                return ast_for_print_stmt(c, n);
+            case del_stmt:
+                return ast_for_del_stmt(c, n);
+            case pass_stmt:
+                return Pass(LINENO(n), n->n_col_offset, c->c_arena);
+            case flow_stmt:
+                return ast_for_flow_stmt(c, n);
+            case import_stmt:
+                return ast_for_import_stmt(c, n);
+            case global_stmt:
+                return ast_for_global_stmt(c, n);
+            case exec_stmt:
+                return ast_for_exec_stmt(c, n);
+            case assert_stmt:
+                return ast_for_assert_stmt(c, n);
+            default:
+                PyErr_Format(PyExc_SystemError,
+                             "unhandled small_stmt: TYPE=%d NCH=%d\n",
+                             TYPE(n), NCH(n));
+                return NULL;
+        }
     }
     else {
-	/* compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt
-			| funcdef | classdef
-	*/
-	node *ch = CHILD(n, 0);
-	REQ(n, compound_stmt);
-	switch (TYPE(ch)) {
-	    case if_stmt:
-		return ast_for_if_stmt(c, ch);
-	    case while_stmt:
-		return ast_for_while_stmt(c, ch);
-	    case for_stmt:
-		return ast_for_for_stmt(c, ch);
-	    case try_stmt:
-		return ast_for_try_stmt(c, ch);
-	    case with_stmt:
-		return ast_for_with_stmt(c, ch);
-	    case funcdef:
-		return ast_for_funcdef(c, ch);
-	    case classdef:
-		return ast_for_classdef(c, ch);
-	    default:
-		PyErr_Format(PyExc_SystemError,
-			     "unhandled small_stmt: TYPE=%d NCH=%d\n",
-			     TYPE(n), NCH(n));
-		return NULL;
-	}
+        /* compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt
+                        | funcdef | classdef
+        */
+        node *ch = CHILD(n, 0);
+        REQ(n, compound_stmt);
+        switch (TYPE(ch)) {
+            case if_stmt:
+                return ast_for_if_stmt(c, ch);
+            case while_stmt:
+                return ast_for_while_stmt(c, ch);
+            case for_stmt:
+                return ast_for_for_stmt(c, ch);
+            case try_stmt:
+                return ast_for_try_stmt(c, ch);
+            case with_stmt:
+                return ast_for_with_stmt(c, ch);
+            case funcdef:
+                return ast_for_funcdef(c, ch);
+            case classdef:
+                return ast_for_classdef(c, ch);
+            default:
+                PyErr_Format(PyExc_SystemError,
+                             "unhandled small_stmt: TYPE=%d NCH=%d\n",
+                             TYPE(n), NCH(n));
+                return NULL;
+        }
     }
 }
 
 static PyObject *
 parsenumber(const char *s)
 {
-	const char *end;
-	long x;
-	double dx;
+        const char *end;
+        long x;
+        double dx;
 #ifndef WITHOUT_COMPLEX
-	Py_complex c;
-	int imflag;
+        Py_complex c;
+        int imflag;
 #endif
 
-	errno = 0;
-	end = s + strlen(s) - 1;
+        errno = 0;
+        end = s + strlen(s) - 1;
 #ifndef WITHOUT_COMPLEX
-	imflag = *end == 'j' || *end == 'J';
+        imflag = *end == 'j' || *end == 'J';
 #endif
-	if (*end == 'l' || *end == 'L')
-		return PyLong_FromString((char *)s, (char **)0, 0);
-	if (s[0] == '0') {
-		x = (long) PyOS_strtoul((char *)s, (char **)&end, 0);
-		if (x < 0 && errno == 0) {
-				return PyLong_FromString((char *)s,
-							 (char **)0,
-							 0);
-		}
-	}
-	else
-		x = PyOS_strtol((char *)s, (char **)&end, 0);
-	if (*end == '\0') {
-		if (errno != 0)
-			return PyLong_FromString((char *)s, (char **)0, 0);
-		return PyInt_FromLong(x);
-	}
-	/* XXX Huge floats may silently fail */
+        if (*end == 'l' || *end == 'L')
+                return PyLong_FromString((char *)s, (char **)0, 0);
+        if (s[0] == '0') {
+                x = (long) PyOS_strtoul((char *)s, (char **)&end, 0);
+                if (x < 0 && errno == 0) {
+                                return PyLong_FromString((char *)s,
+                                                         (char **)0,
+                                                         0);
+                }
+        }
+        else
+                x = PyOS_strtol((char *)s, (char **)&end, 0);
+        if (*end == '\0') {
+                if (errno != 0)
+                        return PyLong_FromString((char *)s, (char **)0, 0);
+                return PyInt_FromLong(x);
+        }
+        /* XXX Huge floats may silently fail */
 #ifndef WITHOUT_COMPLEX
-	if (imflag) {
-		c.real = 0.;
-		PyFPE_START_PROTECT("atof", return 0)
-		c.imag = PyOS_ascii_atof(s);
-		PyFPE_END_PROTECT(c)
-		return PyComplex_FromCComplex(c);
-	}
-	else
+        if (imflag) {
+                c.real = 0.;
+                PyFPE_START_PROTECT("atof", return 0)
+                c.imag = PyOS_ascii_atof(s);
+                PyFPE_END_PROTECT(c)
+                return PyComplex_FromCComplex(c);
+        }
+        else
 #endif
-	{
-		PyFPE_START_PROTECT("atof", return 0)
-		dx = PyOS_ascii_atof(s);
-		PyFPE_END_PROTECT(dx)
-		return PyFloat_FromDouble(dx);
-	}
+        {
+                PyFPE_START_PROTECT("atof", return 0)
+                dx = PyOS_ascii_atof(s);
+                PyFPE_END_PROTECT(dx)
+                return PyFloat_FromDouble(dx);
+        }
 }
 
 static PyObject *
 decode_utf8(const char **sPtr, const char *end, char* encoding)
 {
 #ifndef Py_USING_UNICODE
-	Py_FatalError("decode_utf8 should not be called in this build.");
-	return NULL;
+        Py_FatalError("decode_utf8 should not be called in this build.");
+        return NULL;
 #else
-	PyObject *u, *v;
-	char *s, *t;
-	t = s = (char *)*sPtr;
-	/* while (s < end && *s != '\\') s++; */ /* inefficient for u".." */
-	while (s < end && (*s & 0x80)) s++;
-	*sPtr = s;
-	u = PyUnicode_DecodeUTF8(t, s - t, NULL);
-	if (u == NULL)
-		return NULL;
-	v = PyUnicode_AsEncodedString(u, encoding, NULL);
-	Py_DECREF(u);
-	return v;
+        PyObject *u, *v;
+        char *s, *t;
+        t = s = (char *)*sPtr;
+        /* while (s < end && *s != '\\') s++; */ /* inefficient for u".." */
+        while (s < end && (*s & 0x80)) s++;
+        *sPtr = s;
+        u = PyUnicode_DecodeUTF8(t, s - t, NULL);
+        if (u == NULL)
+                return NULL;
+        v = PyUnicode_AsEncodedString(u, encoding, NULL);
+        Py_DECREF(u);
+        return v;
 #endif
 }
 
 static PyObject *
 decode_unicode(const char *s, size_t len, int rawmode, const char *encoding)
 {
-	PyObject *v, *u;
-	char *buf;
-	char *p;
-	const char *end;
-	if (encoding == NULL) {
-		buf = (char *)s;
-		u = NULL;
-	} else if (strcmp(encoding, "iso-8859-1") == 0) {
-		buf = (char *)s;
-		u = NULL;
-	} else {
-		/* "\XX" may become "\u005c\uHHLL" (12 bytes) */
-		u = PyString_FromStringAndSize((char *)NULL, len * 4);
-		if (u == NULL)
-			return NULL;
-		p = buf = PyString_AsString(u);
-		end = s + len;
-		while (s < end) {
-			if (*s == '\\') {
-				*p++ = *s++;
-				if (*s & 0x80) {
-					strcpy(p, "u005c");
-					p += 5;
-				}
-			}
-			if (*s & 0x80) { /* XXX inefficient */
-				PyObject *w;
-				char *r;
-				Py_ssize_t rn, i;
-				w = decode_utf8(&s, end, "utf-16-be");
-				if (w == NULL) {
-					Py_DECREF(u);
-					return NULL;
-				}
-				r = PyString_AsString(w);
-				rn = PyString_Size(w);
-				assert(rn % 2 == 0);
-				for (i = 0; i < rn; i += 2) {
-					sprintf(p, "\\u%02x%02x",
-						r[i + 0] & 0xFF,
-						r[i + 1] & 0xFF);
-					p += 6;
-				}
-				Py_DECREF(w);
-			} else {
-				*p++ = *s++;
-			}
-		}
-		len = p - buf;
-		s = buf;
-	}
-	if (rawmode)
-		v = PyUnicode_DecodeRawUnicodeEscape(s, len, NULL);
-	else
-		v = PyUnicode_DecodeUnicodeEscape(s, len, NULL);
-	Py_XDECREF(u);
-	return v;
+        PyObject *v, *u;
+        char *buf;
+        char *p;
+        const char *end;
+        if (encoding == NULL) {
+                buf = (char *)s;
+                u = NULL;
+        } else if (strcmp(encoding, "iso-8859-1") == 0) {
+                buf = (char *)s;
+                u = NULL;
+        } else {
+                /* "\XX" may become "\u005c\uHHLL" (12 bytes) */
+                u = PyString_FromStringAndSize((char *)NULL, len * 4);
+                if (u == NULL)
+                        return NULL;
+                p = buf = PyString_AsString(u);
+                end = s + len;
+                while (s < end) {
+                        if (*s == '\\') {
+                                *p++ = *s++;
+                                if (*s & 0x80) {
+                                        strcpy(p, "u005c");
+                                        p += 5;
+                                }
+                        }
+                        if (*s & 0x80) { /* XXX inefficient */
+                                PyObject *w;
+                                char *r;
+                                Py_ssize_t rn, i;
+                                w = decode_utf8(&s, end, "utf-16-be");
+                                if (w == NULL) {
+                                        Py_DECREF(u);
+                                        return NULL;
+                                }
+                                r = PyString_AsString(w);
+                                rn = PyString_Size(w);
+                                assert(rn % 2 == 0);
+                                for (i = 0; i < rn; i += 2) {
+                                        sprintf(p, "\\u%02x%02x",
+                                                r[i + 0] & 0xFF,
+                                                r[i + 1] & 0xFF);
+                                        p += 6;
+                                }
+                                Py_DECREF(w);
+                        } else {
+                                *p++ = *s++;
+                        }
+                }
+                len = p - buf;
+                s = buf;
+        }
+        if (rawmode)
+                v = PyUnicode_DecodeRawUnicodeEscape(s, len, NULL);
+        else
+                v = PyUnicode_DecodeUnicodeEscape(s, len, NULL);
+        Py_XDECREF(u);
+        return v;
 }
 
 /* s is a Python string literal, including the bracketing quote characters,
@@ -3166,75 +3185,75 @@ decode_unicode(const char *s, size_t len, int rawmode, const char *encoding)
 static PyObject *
 parsestr(const char *s, const char *encoding)
 {
-	size_t len;
-	int quote = Py_CHARMASK(*s);
-	int rawmode = 0;
-	int need_encoding;
-	int unicode = 0;
-
-	if (isalpha(quote) || quote == '_') {
-		if (quote == 'u' || quote == 'U') {
-			quote = *++s;
-			unicode = 1;
-		}
-		if (quote == 'r' || quote == 'R') {
-			quote = *++s;
-			rawmode = 1;
-		}
-	}
-	if (quote != '\'' && quote != '\"') {
-		PyErr_BadInternalCall();
-		return NULL;
-	}
-	s++;
-	len = strlen(s);
-	if (len > INT_MAX) {
-		PyErr_SetString(PyExc_OverflowError, 
-				"string to parse is too long");
-		return NULL;
-	}
-	if (s[--len] != quote) {
-		PyErr_BadInternalCall();
-		return NULL;
-	}
-	if (len >= 4 && s[0] == quote && s[1] == quote) {
-		s += 2;
-		len -= 2;
-		if (s[--len] != quote || s[--len] != quote) {
-			PyErr_BadInternalCall();
-			return NULL;
-		}
-	}
+        size_t len;
+        int quote = Py_CHARMASK(*s);
+        int rawmode = 0;
+        int need_encoding;
+        int unicode = 0;
+
+        if (isalpha(quote) || quote == '_') {
+                if (quote == 'u' || quote == 'U') {
+                        quote = *++s;
+                        unicode = 1;
+                }
+                if (quote == 'r' || quote == 'R') {
+                        quote = *++s;
+                        rawmode = 1;
+                }
+        }
+        if (quote != '\'' && quote != '\"') {
+                PyErr_BadInternalCall();
+                return NULL;
+        }
+        s++;
+        len = strlen(s);
+        if (len > INT_MAX) {
+                PyErr_SetString(PyExc_OverflowError, 
+                                "string to parse is too long");
+                return NULL;
+        }
+        if (s[--len] != quote) {
+                PyErr_BadInternalCall();
+                return NULL;
+        }
+        if (len >= 4 && s[0] == quote && s[1] == quote) {
+                s += 2;
+                len -= 2;
+                if (s[--len] != quote || s[--len] != quote) {
+                        PyErr_BadInternalCall();
+                        return NULL;
+                }
+        }
 #ifdef Py_USING_UNICODE
-	if (unicode || Py_UnicodeFlag) {
-		return decode_unicode(s, len, rawmode, encoding);
-	}
+        if (unicode || Py_UnicodeFlag) {
+                return decode_unicode(s, len, rawmode, encoding);
+        }
 #endif
-	need_encoding = (encoding != NULL &&
-			 strcmp(encoding, "utf-8") != 0 &&
-			 strcmp(encoding, "iso-8859-1") != 0);
-	if (rawmode || strchr(s, '\\') == NULL) {
-		if (need_encoding) {
+        need_encoding = (encoding != NULL &&
+                         strcmp(encoding, "utf-8") != 0 &&
+                         strcmp(encoding, "iso-8859-1") != 0);
+        if (rawmode || strchr(s, '\\') == NULL) {
+                if (need_encoding) {
 #ifndef Py_USING_UNICODE
-			/* This should not happen - we never see any other
-			   encoding. */
-			Py_FatalError(
-			    "cannot deal with encodings in this build.");
+                        /* This should not happen - we never see any other
+                           encoding. */
+                        Py_FatalError(
+                            "cannot deal with encodings in this build.");
 #else
-			PyObject *v, *u = PyUnicode_DecodeUTF8(s, len, NULL);
-			if (u == NULL)
-				return NULL;
-			v = PyUnicode_AsEncodedString(u, encoding, NULL);
-			Py_DECREF(u);
-			return v;
+                        PyObject *v, *u = PyUnicode_DecodeUTF8(s, len, NULL);
+                        if (u == NULL)
+                                return NULL;
+                        v = PyUnicode_AsEncodedString(u, encoding, NULL);
+                        Py_DECREF(u);
+                        return v;
 #endif
-		} else {
-			return PyString_FromStringAndSize(s, len);
-		}
-	}
+                } else {
+                        return PyString_FromStringAndSize(s, len);
+                }
+        }
 
-	return PyString_DecodeEscape(s, len, NULL, unicode,
-				     need_encoding ? encoding : NULL);
+        return PyString_DecodeEscape(s, len, NULL, unicode,
+                                     need_encoding ? encoding : NULL);
 }
 
 /* Build a Python string object out of a STRING atom.  This takes care of
@@ -3244,36 +3263,36 @@ parsestr(const char *s, const char *encoding)
 static PyObject *
 parsestrplus(struct compiling *c, const node *n)
 {
-	PyObject *v;
-	int i;
-	REQ(CHILD(n, 0), STRING);
-	if ((v = parsestr(STR(CHILD(n, 0)), c->c_encoding)) != NULL) {
-		/* String literal concatenation */
-		for (i = 1; i < NCH(n); i++) {
-			PyObject *s;
-			s = parsestr(STR(CHILD(n, i)), c->c_encoding);
-			if (s == NULL)
-				goto onError;
-			if (PyString_Check(v) && PyString_Check(s)) {
-				PyString_ConcatAndDel(&v, s);
-				if (v == NULL)
-				    goto onError;
-			}
+        PyObject *v;
+        int i;
+        REQ(CHILD(n, 0), STRING);
+        if ((v = parsestr(STR(CHILD(n, 0)), c->c_encoding)) != NULL) {
+                /* String literal concatenation */
+                for (i = 1; i < NCH(n); i++) {
+                        PyObject *s;
+                        s = parsestr(STR(CHILD(n, i)), c->c_encoding);
+                        if (s == NULL)
+                                goto onError;
+                        if (PyString_Check(v) && PyString_Check(s)) {
+                                PyString_ConcatAndDel(&v, s);
+                                if (v == NULL)
+                                    goto onError;
+                        }
 #ifdef Py_USING_UNICODE
-			else {
-				PyObject *temp = PyUnicode_Concat(v, s);
-				Py_DECREF(s);
-				Py_DECREF(v);
-				v = temp;
-				if (v == NULL)
-				    goto onError;
-			}
+                        else {
+                                PyObject *temp = PyUnicode_Concat(v, s);
+                                Py_DECREF(s);
+                                Py_DECREF(v);
+                                v = temp;
+                                if (v == NULL)
+                                    goto onError;
+                        }
 #endif
-		}
-	}
-	return v;
+                }
+        }
+        return v;
 
  onError:
-	Py_XDECREF(v);
-	return NULL;
+        Py_XDECREF(v);
+        return NULL;
 }