- fixed lookahead assertions (#10, #11, #12)

- untabified sre_constants.py

4 files changed, 93 insertions, 61 deletions

diff --git a/Lib/sre_compile.py b/Lib/sre_compile.py
index 9fdc8f3..0829c00 100644
--- a/Lib/sre_compile.py
+++ b/Lib/sre_compile.py
@@ -26,52 +26,12 @@ def _compile(code, pattern, flags):
     # internal: compile a (sub)pattern
     emit = code.append
     for op, av in pattern:
-        if op is ANY:
-            if flags & SRE_FLAG_DOTALL:
-                emit(OPCODES[op])
-            else:
-                emit(OPCODES[CATEGORY])
-                emit(CHCODES[CATEGORY_NOT_LINEBREAK])
-        elif op in (SUCCESS, FAILURE):
-            emit(OPCODES[op])
-        elif op is AT:
-            emit(OPCODES[op])
-            if flags & SRE_FLAG_MULTILINE:
-                emit(ATCODES[AT_MULTILINE[av]])
-            else:
-                emit(ATCODES[av])
-        elif op is BRANCH:
-            emit(OPCODES[op])
-            tail = []
-            for av in av[1]:
-                skip = len(code); emit(0)
-                _compile(code, av, flags)
-                emit(OPCODES[JUMP])
-                tail.append(len(code)); emit(0)
-                code[skip] = len(code) - skip
-            emit(0) # end of branch
-            for tail in tail:
-                code[tail] = len(code) - tail
-        elif op is CALL:
-            emit(OPCODES[op])
-            skip = len(code); emit(0)
-            _compile(code, av, flags)
-            emit(OPCODES[SUCCESS])
-            code[skip] = len(code) - skip
-        elif op is CATEGORY:
-            emit(OPCODES[op])
-            if flags & SRE_FLAG_LOCALE:
-                emit(CHCODES[CH_LOCALE[av]])
-            elif flags & SRE_FLAG_UNICODE:
-                emit(CHCODES[CH_UNICODE[av]])
-            else:
-                emit(CHCODES[av])
-        elif op is GROUP:
+        if op in (LITERAL, NOT_LITERAL):
             if flags & SRE_FLAG_IGNORECASE:
                 emit(OPCODES[OP_IGNORE[op]])
             else:
                 emit(OPCODES[op])
-            emit(av-1)
+            emit(ord(av))
         elif op is IN:
             if flags & SRE_FLAG_IGNORECASE:
                 emit(OPCODES[OP_IGNORE[op]])
@@ -101,15 +61,12 @@ def _compile(code, pattern, flags):
                     raise error, "internal: unsupported set operator"
             emit(OPCODES[FAILURE])
             code[skip] = len(code) - skip
-        elif op in (LITERAL, NOT_LITERAL):
-            if flags & SRE_FLAG_IGNORECASE:
-                emit(OPCODES[OP_IGNORE[op]])
-            else:
+        elif op is ANY:
+            if flags & SRE_FLAG_DOTALL:
                 emit(OPCODES[op])
-            emit(ord(av))
-        elif op is MARK:
-            emit(OPCODES[op])
-            emit(av)
+            else:
+                emit(OPCODES[CATEGORY])
+                emit(CHCODES[CATEGORY_NOT_LINEBREAK])
         elif op in (REPEAT, MIN_REPEAT, MAX_REPEAT):
             if flags & SRE_FLAG_TEMPLATE:
                 emit(OPCODES[REPEAT])
@@ -150,6 +107,49 @@ def _compile(code, pattern, flags):
             if group:
                 emit(OPCODES[MARK])
                 emit((group-1)*2+1)
+        elif op in (SUCCESS, FAILURE):
+            emit(OPCODES[op])
+        elif op in (ASSERT, ASSERT_NOT, CALL):
+            emit(OPCODES[op])
+            skip = len(code); emit(0)
+            _compile(code, av, flags)
+            emit(OPCODES[SUCCESS])
+            code[skip] = len(code) - skip
+        elif op is AT:
+            emit(OPCODES[op])
+            if flags & SRE_FLAG_MULTILINE:
+                emit(ATCODES[AT_MULTILINE[av]])
+            else:
+                emit(ATCODES[av])
+        elif op is BRANCH:
+            emit(OPCODES[op])
+            tail = []
+            for av in av[1]:
+                skip = len(code); emit(0)
+                _compile(code, av, flags)
+                emit(OPCODES[JUMP])
+                tail.append(len(code)); emit(0)
+                code[skip] = len(code) - skip
+            emit(0) # end of branch
+            for tail in tail:
+                code[tail] = len(code) - tail
+        elif op is CATEGORY:
+            emit(OPCODES[op])
+            if flags & SRE_FLAG_LOCALE:
+                emit(CHCODES[CH_LOCALE[av]])
+            elif flags & SRE_FLAG_UNICODE:
+                emit(CHCODES[CH_UNICODE[av]])
+            else:
+                emit(CHCODES[av])
+        elif op is GROUP:
+            if flags & SRE_FLAG_IGNORECASE:
+                emit(OPCODES[OP_IGNORE[op]])
+            else:
+                emit(OPCODES[op])
+            emit(av-1)
+        elif op is MARK:
+            emit(OPCODES[op])
+            emit(av)
         else:
             raise ValueError, ("unsupported operand type", op)
 
diff --git a/Lib/sre_constants.py b/Lib/sre_constants.py
index f5e7894..45f4f48 100644
--- a/Lib/sre_constants.py
+++ b/Lib/sre_constants.py
@@ -23,6 +23,7 @@ SUCCESS = "success"
 
 ANY = "any"
 ASSERT = "assert"
+ASSERT_NOT = "assert_not"
 AT = "at"
 BRANCH = "branch"
 CALL = "call"
@@ -81,7 +82,7 @@ OPCODES = [
     FAILURE, SUCCESS,
 
     ANY,
-    ASSERT,
+    ASSERT, ASSERT_NOT,
     AT,
     BRANCH,
     CALL,
@@ -121,8 +122,8 @@ def makedict(list):
     d = {}
     i = 0
     for item in list:
-	d[item] = i
-	i = i + 1
+        d[item] = i
+        i = i + 1
     return d
 
 OPCODES = makedict(OPCODES)
@@ -176,12 +177,27 @@ SRE_FLAG_VERBOSE = 64
 if __name__ == "__main__":
     import string
     def dump(f, d, prefix):
-	items = d.items()
-	items.sort(lambda a, b: cmp(a[1], b[1]))
-	for k, v in items:
-	    f.write("#define %s_%s %s\n" % (prefix, string.upper(k), v))
+        items = d.items()
+        items.sort(lambda a, b: cmp(a[1], b[1]))
+        for k, v in items:
+            f.write("#define %s_%s %s\n" % (prefix, string.upper(k), v))
     f = open("sre_constants.h", "w")
-    f.write("/* generated from sre_constants.py */\n")
+    f.write("""\
+/*
+ * Secret Labs' Regular Expression Engine
+ *
+ * regular expression matching engine
+ *
+ * NOTE: This file is generated by sre_constants.py.  If you need
+ * to change anything in here, edit sre_constants.py and run it.
+ *
+ * Copyright (c) 1997-2000 by Secret Labs AB.  All rights reserved.
+ *
+ * See the _sre.c file for information on usage and redistribution.
+ */
+
+""")
+
     dump(f, OPCODES, "SRE_OP")
     dump(f, ATCODES, "SRE")
     dump(f, CHCODES, "SRE")
diff --git a/Lib/sre_parse.py b/Lib/sre_parse.py
index a6f3082..d3dbe00 100644
--- a/Lib/sre_parse.py
+++ b/Lib/sre_parse.py
@@ -470,6 +470,25 @@ def _parse(source, state, flags=0):
                         if source.next is None or source.next == ")":
                             break
                         source.get()
+                elif source.next in ("=", "!"):
+                    # lookahead assertions
+                    char = source.get()
+                    b = []
+                    while 1:
+                        p = _parse(source, state, flags)
+                        if source.next == ")":
+                            if b:
+                                b.append(p)
+                                p = _branch(state, b)
+                            if char == "=":
+                                subpattern.append((ASSERT, p))
+                            else:
+                                subpattern.append((ASSERT_NOT, p))
+                            break
+                        elif source.match("|"):
+                            b.append(p)
+                        else:
+                            raise error, "pattern not properly closed"
                 else:
                     # flags
                     while FLAGS.has_key(source.next):
diff --git a/Lib/test/output/test_sre b/Lib/test/output/test_sre
index 75caa55..d3732b5 100644
--- a/Lib/test/output/test_sre
+++ b/Lib/test/output/test_sre
@@ -6,7 +6,4 @@ test_support -- test failed re module cPickle
 === grouping error ('([^/]*/)*sub1/', 'd:msgs/tdir/sub1/trial/away.cpp', 0, 'found+"-"+g1', 'd:msgs/tdir/sub1/-tdir/') 'd:msgs/tdir/sub1/-trial/' should be 'd:msgs/tdir/sub1/-tdir/'
 === grouping error ('([abc])*bcd', 'abcd', 0, 'found+"-"+g1', 'abcd-a') 'abcd-c' should be 'abcd-a'
 === grouping error ('(?i)([abc])*bcd', 'ABCD', 0, 'found+"-"+g1', 'ABCD-A') 'ABCD-C' should be 'ABCD-A'
-=== Syntax error: ('a(?!b).', 'abad', 0, 'found', 'ad')
-=== Syntax error: ('a(?=d).', 'abad', 0, 'found', 'ad')
-=== Syntax error: ('a(?=c|d).', 'abad', 0, 'found', 'ad')
 === Failed incorrectly ('^(.+)?B', 'AB', 0, 'g1', 'A')