diff options
Diffstat (limited to 'Demo/parser/unparse.py')
| -rw-r--r-- | Demo/parser/unparse.py | 101 |
1 files changed, 50 insertions, 51 deletions
diff --git a/Demo/parser/unparse.py b/Demo/parser/unparse.py index 1c6e933..751ea6f 100644 --- a/Demo/parser/unparse.py +++ b/Demo/parser/unparse.py @@ -4,6 +4,19 @@ import _ast import cStringIO import os +def interleave(inter, f, seq): + """Call f on each item in seq, calling inter() in between. + """ + seq = iter(seq) + try: + f(seq.next()) + except StopIteration: + pass + else: + for x in seq: + inter() + f(x) + class Unparser: """Methods in this class recursively traverse an AST and output source code for the abstract syntax; original formatting @@ -63,26 +76,13 @@ class Unparser: def _Import(self, t): self.fill("import ") - first = True - for a in t.names: - if first: - first = False - else: - self.write(", ") - self.write(a.name) - if a.asname: - self.write(" as "+a.asname) + interleave(lambda: self.write(", "), self.dispatch, t.names) def _ImportFrom(self, t): self.fill("from ") self.write(t.module) self.write(" import ") - for i, a in enumerate(t.names): - if i == 0: - self.write(", ") - self.write(a.name) - if a.asname: - self.write(" as "+a.asname) + interleave(lambda: self.write(", "), self.dispatch, t.names) # XXX(jpe) what is level for? def _Assign(self, t): @@ -99,8 +99,9 @@ class Unparser: self.dispatch(t.value) def _Return(self, t): - self.fill("return ") + self.fill("return") if t.value: + self.write(" ") self.dispatch(t.value) def _Pass(self, t): @@ -138,18 +139,16 @@ class Unparser: self.write(",") def _Global(self, t): - self.fill("global") - for i, n in enumerate(t.names): - if i != 0: - self.write(",") - self.write(" " + n) + self.fill("global ") + interleave(lambda: self.write(", "), self.write, t.names) def _Yield(self, t): - self.fill("yield") + self.write("(") + self.write("yield") if t.value: - self.write(" (") + self.write(" ") self.dispatch(t.value) - self.write(")") + self.write(")") def _Raise(self, t): self.fill('raise ') @@ -188,8 +187,9 @@ class Unparser: self.leave() def _excepthandler(self, t): - self.fill("except ") + self.fill("except") if t.type: + self.write(" ") self.dispatch(t.type) if t.name: self.write(", ") @@ -289,9 +289,7 @@ class Unparser: def _List(self, t): self.write("[") - for e in t.elts: - self.dispatch(e) - self.write(", ") + interleave(lambda: self.write(", "), self.dispatch, t.elts) self.write("]") def _ListComp(self, t): @@ -318,30 +316,31 @@ class Unparser: self.dispatch(if_clause) def _IfExp(self, t): + self.write("(") self.dispatch(t.body) self.write(" if ") self.dispatch(t.test) - if t.orelse: - self.write(" else ") - self.dispatch(t.orelse) + self.write(" else ") + self.dispatch(t.orelse) + self.write(")") def _Dict(self, t): self.write("{") - for k,v in zip(t.keys, t.values): + def writem((k, v)): self.dispatch(k) - self.write(" : ") + self.write(": ") self.dispatch(v) - self.write(", ") + interleave(lambda: self.write(", "), writem, zip(t.keys, t.values)) self.write("}") def _Tuple(self, t): - if not t.elts: - self.write("()") - return self.write("(") - for e in t.elts: - self.dispatch(e) - self.write(", ") + if len(t.elts) == 1: + (elt,) = t.elts + self.dispatch(elt) + self.write(",") + else: + interleave(lambda: self.write(", "), self.dispatch, t.elts) self.write(")") unop = {"Invert":"~", "Not": "not", "UAdd":"+", "USub":"-"} @@ -357,7 +356,7 @@ class Unparser: def _BinOp(self, t): self.write("(") self.dispatch(t.left) - self.write(")" + self.binop[t.op.__class__.__name__] + "(") + self.write(" " + self.binop[t.op.__class__.__name__] + " ") self.dispatch(t.right) self.write(")") @@ -367,17 +366,15 @@ class Unparser: self.write("(") self.dispatch(t.left) for o, e in zip(t.ops, t.comparators): - self.write(") " +self.cmpops[o.__class__.__name__] + " (") + self.write(" " + self.cmpops[o.__class__.__name__] + " ") self.dispatch(e) self.write(")") boolops = {_ast.And: 'and', _ast.Or: 'or'} def _BoolOp(self, t): self.write("(") - self.dispatch(t.values[0]) - for v in t.values[1:]: - self.write(" %s " % self.boolops[t.op.__class__]) - self.dispatch(v) + s = " %s " % self.boolops[t.op.__class__] + interleave(lambda: self.write(s), self.dispatch, t.values) self.write(")") def _Attribute(self,t): @@ -433,10 +430,7 @@ class Unparser: self.dispatch(t.step) def _ExtSlice(self, t): - for i, d in enumerate(t.dims): - if i != 0: - self.write(': ') - self.dispatch(d) + interleave(lambda: self.write(', '), self.dispatch, t.dims) # others def _arguments(self, t): @@ -472,9 +466,14 @@ class Unparser: self.write(": ") self.dispatch(t.body) + def _alias(self, t): + self.write(t.name) + if t.asname: + self.write(" as "+t.asname) + def roundtrip(filename, output=sys.stdout): source = open(filename).read() - tree = compile(source, filename, "exec", 0x400) + tree = compile(source, filename, "exec", _ast.PyCF_ONLY_AST) Unparser(tree, output) |