Backport of the print function, using a __future__ import.

This work is substantially Anthony Baxter's, from issue
1633807.  I just freshened it, made a few minor tweaks,
and added the test cases.  I also created issue 2412,
which is to check for 2to3's behavior with the print
function.  I also added myself to ACKS.

2 files changed, 10 insertions, 28 deletions

diff --git a/Parser/parser.c b/Parser/parser.c
index 2ce84cd..61da37d 100644
--- a/Parser/parser.c
+++ b/Parser/parser.c
@@ -149,12 +149,10 @@ classify(parser_state *ps, int type, char *str)
 			    strcmp(l->lb_str, s) != 0)
 				continue;
 #ifdef PY_PARSER_REQUIRES_FUTURE_KEYWORD
-			if (!(ps->p_flags & CO_FUTURE_WITH_STATEMENT)) {
-				if (s[0] == 'w' && strcmp(s, "with") == 0)
-					break; /* not a keyword yet */
-				else if (s[0] == 'a' && strcmp(s, "as") == 0)
-					break; /* not a keyword yet */
-			}
+                        if (ps->p_flags & CO_FUTURE_PRINT_FUNCTION &&
+                            s[0] == 'p' && strcmp(s, "print") == 0) { 
+                                break; /* no longer a keyword */
+                        }
 #endif
 			D(printf("It's a keyword\n"));
 			return n - i;
@@ -208,6 +206,10 @@ future_hack(parser_state *ps)
 		    strcmp(STR(CHILD(cch, 0)), "with_statement") == 0) {
 			ps->p_flags |= CO_FUTURE_WITH_STATEMENT;
 			break;
+		} else if (NCH(cch) >= 1 && TYPE(CHILD(cch, 0)) == NAME &&
+		    strcmp(STR(CHILD(cch, 0)), "print_function") == 0) {
+			ps->p_flags |= CO_FUTURE_PRINT_FUNCTION;
+			break;
 		}
 	}
 }
diff --git a/Parser/parsetok.c b/Parser/parsetok.c
index f3d8462..e4db574 100644
--- a/Parser/parsetok.c
+++ b/Parser/parsetok.c
@@ -123,8 +123,8 @@ parsetok(struct tok_state *tok, grammar *g, int start, perrdetail *err_ret,
 		return NULL;
 	}
 #ifdef PY_PARSER_REQUIRES_FUTURE_KEYWORD
-	if (flags & PyPARSE_WITH_IS_KEYWORD)
-		ps->p_flags |= CO_FUTURE_WITH_STATEMENT;
+	if (flags & PyPARSE_PRINT_IS_FUNCTION)
+		ps->p_flags |= CO_FUTURE_PRINT_FUNCTION;
 #endif
 
 	for (;;) {
@@ -167,26 +167,6 @@ parsetok(struct tok_state *tok, grammar *g, int start, perrdetail *err_ret,
 		str[len] = '\0';
 
 #ifdef PY_PARSER_REQUIRES_FUTURE_KEYWORD
-		/* This is only necessary to support the "as" warning, but
-		   we don't want to warn about "as" in import statements. */
-		if (type == NAME &&
-		    len == 6 && str[0] == 'i' && strcmp(str, "import") == 0)
-			handling_import = 1;
-
-		/* Warn about with as NAME */
-		if (type == NAME &&
-		    !(ps->p_flags & CO_FUTURE_WITH_STATEMENT)) {
-		    if (len == 4 && str[0] == 'w' && strcmp(str, "with") == 0)
-			warn(with_msg, err_ret->filename, tok->lineno);
-		    else if (!(handling_import || handling_with) &&
-		             len == 2 && str[0] == 'a' &&
-			     strcmp(str, "as") == 0)
-			warn(as_msg, err_ret->filename, tok->lineno);
-		}
-		else if (type == NAME &&
-			 (ps->p_flags & CO_FUTURE_WITH_STATEMENT) &&
-			 len == 4 && str[0] == 'w' && strcmp(str, "with") == 0)
-			handling_with = 1;
 #endif
 		if (a >= tok->line_start)
 			col_offset = a - tok->line_start;