The BDFL has retired! Long live the FLUFL (Friendly Language Uncle For Life)!

Grammar/Grammar

@@ -87,7 +87,7 @@ or_test: and_test ('or' and_test)*
 and_test: not_test ('and' not_test)*
 not_test: 'not' not_test | comparison
 comparison: star_expr (comp_op star_expr)*
-comp_op: '<'|'>'|'=='|'>='|'<='|'!='|'in'|'not' 'in'|'is'|'is' 'not'
+comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'
 star_expr: ['*'] expr
 expr: xor_expr ('|' xor_expr)*
 xor_expr: and_expr ('^' and_expr)*

Include/code.h

@@ -52,10 +52,12 @@ typedef struct {
 #define CO_FUTURE_UNICODE_LITERALS 0x20000
 #endif
 
+#define CO_FUTURE_BARRY_AS_BDFL  0x40000
+
 /* This should be defined if a future statement modifies the syntax.
    For example, when a keyword is added.
 */
-/* #define PY_PARSER_REQUIRES_FUTURE_KEYWORD */
+#define PY_PARSER_REQUIRES_FUTURE_KEYWORD
 
 #define CO_MAXBLOCKS 20 /* Max static block nesting within a function */
 

Include/compile.h

@@ -26,6 +26,7 @@ typedef struct {
 #define FUTURE_WITH_STATEMENT "with_statement"
 #define FUTURE_PRINT_FUNCTION "print_function"
 #define FUTURE_UNICODE_LITERALS "unicode_literals"
+#define FUTURE_BARRY_AS_BDFL "barry_as_FLUFL"
 
 struct _mod; /* Declare the existence of this type */
 PyAPI_FUNC(PyCodeObject *) PyAST_Compile(struct _mod *, const char *,

Include/parsetok.h

@@ -30,6 +30,7 @@ typedef struct {
 #endif
 
 #define PyPARSE_IGNORE_COOKIE 0x0010
+#define PyPARSE_BARRY_AS_BDFL 0x0020
 
 PyAPI_FUNC(node *) PyParser_ParseString(const char *, grammar *, int,
                                               perrdetail *);

Include/pythonrun.h

@@ -7,7 +7,7 @@
 extern "C" {
 #endif
 
-#define PyCF_MASK 0
+#define PyCF_MASK CO_FUTURE_BARRY_AS_BDFL
 #define PyCF_MASK_OBSOLETE 0
 #define PyCF_SOURCE_IS_UTF8  0x0100
 #define PyCF_DONT_IMPLY_DEDENT 0x0200

Lib/__future__.py

@@ -70,6 +70,7 @@ CO_FUTURE_ABSOLUTE_IMPORT = 0x4000 # perform absolute imports by default
 CO_FUTURE_WITH_STATEMENT  = 0x8000   # with statement
 CO_FUTURE_PRINT_FUNCTION  = 0x10000   # print function
 CO_FUTURE_UNICODE_LITERALS = 0x20000 # unicode string literals
+CO_FUTURE_BARRY_AS_BDFL = 0x40000
 
 class _Feature:
     def __init__(self, optionalRelease, mandatoryRelease, compiler_flag):
@@ -126,3 +127,7 @@ print_function = _Feature((2, 6, 0, "alpha", 2),
 unicode_literals = _Feature((2, 6, 0, "alpha", 2),
                             (3, 0, 0, "alpha", 0),
                             CO_FUTURE_UNICODE_LITERALS)
+
+barry_as_FLUFL = _Feature((3, 1, 0, "alpha", 2),
+                         (3, 9, 0, "alpha", 0),
+                         CO_FUTURE_BARRY_AS_BDFL)

Lib/test/test_flufl.py

+import __future__
+import unittest
+
+class FLUFLTests(unittest.TestCase):
+
+    def test_barry_as_bdfl(self):
+        code = "from __future__ import barry_as_FLUFL; 2 {0} 3"
+        compile(code.format('<>'), '<BDFL test>', 'exec',
+                __future__.CO_FUTURE_BARRY_AS_BDFL)
+        self.assertRaises(SyntaxError, compile, code.format('!='),
+                            '<FLUFL test>', 'exec',
+                            __future__.CO_FUTURE_BARRY_AS_BDFL)
+
+    def test_guido_as_bdfl(self):
+        code = '2 {0} 3'
+        compile(code.format('!='), '<BDFL test>', 'exec')
+        self.assertRaises(SyntaxError, compile, code.format('<>'),
+                            '<FLUFL test>', 'exec')
+
+
+def test_main():
+    from test.support import run_unittest
+    run_unittest(FLUFLTests)
+
+
+if __name__ == '__main__':
+    test_main()

Parser/parser.c

@@ -149,6 +149,7 @@ classify(parser_state *ps, int type, char *str)
 			    strcmp(l->lb_str, s) != 0)
 				continue;
 #ifdef PY_PARSER_REQUIRES_FUTURE_KEYWORD
+#if 0
                         /* Leaving this in as an example */
 			if (!(ps->p_flags & CO_FUTURE_WITH_STATEMENT)) {
 				if (s[0] == 'w' && strcmp(s, "with") == 0)
@@ -156,6 +157,7 @@ classify(parser_state *ps, int type, char *str)
 				else if (s[0] == 'a' && strcmp(s, "as") == 0)
 					break; /* not a keyword yet */
 			}
+#endif
 #endif
 			D(printf("It's a keyword\n"));
 			return n - i;
@@ -178,6 +180,7 @@ classify(parser_state *ps, int type, char *str)
 }
 
 #ifdef PY_PARSER_REQUIRES_FUTURE_KEYWORD
+#if 0
 /* Leaving this in as an example */
 static void
 future_hack(parser_state *ps)
@@ -218,6 +221,7 @@ future_hack(parser_state *ps)
 		}
 	}
 }
+#endif
 #endif /* future keyword */
 
 int
@@ -278,10 +282,12 @@ PyParser_AddToken(register parser_state *ps, register int type, char *str,
 						 d->d_name,
 						 ps->p_stack.s_top->s_state));
 #ifdef PY_PARSER_REQUIRES_FUTURE_KEYWORD
+#if 0
 					if (d->d_name[0] == 'i' &&
 					    strcmp(d->d_name,
 						   "import_stmt") == 0)
 						future_hack(ps);
+#endif
 #endif
 					s_pop(&ps->p_stack);
 					if (s_empty(&ps->p_stack)) {
@@ -296,9 +302,11 @@ PyParser_AddToken(register parser_state *ps, register int type, char *str,
 		
 		if (s->s_accept) {
 #ifdef PY_PARSER_REQUIRES_FUTURE_KEYWORD
+#if 0
 			if (d->d_name[0] == 'i' &&
 			    strcmp(d->d_name, "import_stmt") == 0)
 				future_hack(ps);
+#endif
 #endif
 			/* Pop this dfa and try again */
 			s_pop(&ps->p_stack);

Parser/parsetok.c

@@ -100,6 +100,7 @@ PyParser_ParseFileFlagsEx(FILE *fp, const char *filename,
 }
 
 #ifdef PY_PARSER_REQUIRES_FUTURE_KEYWORD
+#if 0
 static char with_msg[] =
 "%s:%d: Warning: 'with' will become a reserved keyword in Python 2.6\n";
 
@@ -114,6 +115,7 @@ warn(const char *msg, const char *filename, int lineno)
 	PySys_WriteStderr(msg, filename, lineno);
 }
 #endif
+#endif
 
 /* Parse input coming from the given tokenizer structure.
    Return error code. */
@@ -133,8 +135,8 @@ 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_BARRY_AS_BDFL)
+		ps->p_flags |= CO_FUTURE_BARRY_AS_BDFL;
 #endif
 
 	for (;;) {
@@ -177,26 +179,20 @@ 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);
+		if (type == NOTEQUAL) {
+			if (!(ps->p_flags & CO_FUTURE_BARRY_AS_BDFL) &&
+					strcmp(str, "!=")) {
+				err_ret->error = E_SYNTAX;
+				break;
+			}
+			else if ((ps->p_flags & CO_FUTURE_BARRY_AS_BDFL) &&
+					strcmp(str, "<>")) {
+				err_ret->text = "with Barry as BDFL, use '<>' "
+						"instead of '!='";
+				err_ret->error = E_SYNTAX;
+				break;
+			}
 		}
-		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;

Parser/tokenizer.c

@@ -1040,6 +1040,7 @@ PyToken_TwoChars(int c1, int c2)
 		break;
 	case '<':
 		switch (c2) {
+		case '>':	return NOTEQUAL;
 		case '=':	return LESSEQUAL;
 		case '<':	return LEFTSHIFT;
 		}

Python/future.c

@@ -39,6 +39,8 @@ future_check_features(PyFutureFeatures *ff, stmt_ty s, const char *filename)
 			continue;
 		} else if (strcmp(feature, FUTURE_UNICODE_LITERALS) == 0) {
 			continue;
+		} else if (strcmp(feature, FUTURE_BARRY_AS_BDFL) == 0) {
+			ff->ff_features |= CO_FUTURE_BARRY_AS_BDFL;
 		} else if (strcmp(feature, "braces") == 0) {
 			PyErr_SetString(PyExc_SyntaxError,
 					"not a chance");

Python/pythonrun.c

@@ -1011,6 +1011,8 @@ static int PARSER_FLAGS(PyCompilerFlags *flags)
 		parser_flags |= PyPARSE_DONT_IMPLY_DEDENT;
 	if (flags->cf_flags & PyCF_IGNORE_COOKIE)
 		parser_flags |= PyPARSE_IGNORE_COOKIE;
+	if (flags->cf_flags & CO_FUTURE_BARRY_AS_BDFL)
+		parser_flags |= PyPARSE_BARRY_AS_BDFL;
 	return parser_flags;
 }