Add fnmatch module to stdlib (#141)

third_party/stdlib/fnmatch.py

+"""Filename matching with shell patterns.
+
+fnmatch(FILENAME, PATTERN) matches according to the local convention.
+fnmatchcase(FILENAME, PATTERN) always takes case in account.
+
+The functions operate by translating the pattern into a regular
+expression.  They cache the compiled regular expressions for speed.
+
+The function translate(PATTERN) returns a regular expression
+corresponding to PATTERN.  (It does not compile it.)
+"""
+
+import re
+
+__all__ = ["filter", "fnmatch", "fnmatchcase", "translate"]
+
+_cache = {}
+_MAXCACHE = 100
+
+def _purge():
+    """Clear the pattern cache"""
+    # _cache.clear()
+    globals()['_cache'] = {}
+
+def fnmatch(name, pat):
+    """Test whether FILENAME matches PATTERN.
+
+    Patterns are Unix shell style:
+
+    *       matches everything
+    ?       matches any single character
+    [seq]   matches any character in seq
+    [!seq]  matches any char not in seq
+
+    An initial period in FILENAME is not special.
+    Both FILENAME and PATTERN are first case-normalized
+    if the operating system requires it.
+    If you don't want this, use fnmatchcase(FILENAME, PATTERN).
+    """
+
+    # import os
+    # name = os.path.normcase(name)
+    # pat = os.path.normcase(pat)
+    return fnmatchcase(name, pat)
+
+def filter(names, pat):
+    """Return the subset of the list NAMES that match PAT"""
+    import os
+    # import posixpath
+    result=[]
+    # pat=os.path.normcase(pat)
+    try:
+        re_pat = _cache[pat]
+    except KeyError:
+        res = translate(pat)
+        if len(_cache) >= _MAXCACHE:
+            # _cache.clear()
+            globals()['_cache'] = {}
+        _cache[pat] = re_pat = re.compile(res)
+    match = re_pat.match
+    # if os.path is posixpath:
+    if 1:
+        # normcase on posix is NOP. Optimize it away from the loop.
+        for name in names:
+            if match(name):
+                result.append(name)
+    else:
+        for name in names:
+            if match(os.path.normcase(name)):
+                result.append(name)
+    return result
+
+def fnmatchcase(name, pat):
+    """Test whether FILENAME matches PATTERN, including case.
+
+    This is a version of fnmatch() which doesn't case-normalize
+    its arguments.
+    """
+
+    try:
+        re_pat = _cache[pat]
+    except KeyError:
+        res = translate(pat)
+        if len(_cache) >= _MAXCACHE:
+            # _cache.clear()
+            globals()['_cache'] = {}
+        _cache[pat] = re_pat = re.compile(res)
+    return re_pat.match(name) is not None
+
+def translate(pat):
+    """Translate a shell PATTERN to a regular expression.
+
+    There is no way to quote meta-characters.
+    """
+
+    i, n = 0, len(pat)
+    res = ''
+    while i < n:
+        c = pat[i]
+        i = i+1
+        if c == '*':
+            res = res + '.*'
+        elif c == '?':
+            res = res + '.'
+        elif c == '[':
+            j = i
+            if j < n and pat[j] == '!':
+                j = j+1
+            if j < n and pat[j] == ']':
+                j = j+1
+            while j < n and pat[j] != ']':
+                j = j+1
+            if j >= n:
+                res = res + '\\['
+            else:
+                stuff = pat[i:j].replace('\\','\\\\')
+                i = j+1
+                if stuff[0] == '!':
+                    stuff = '^' + stuff[1:]
+                elif stuff[0] == '^':
+                    stuff = '\\' + stuff
+                res = '%s[%s]' % (res, stuff)
+        else:
+            res = res + re.escape(c)
+    return res + '\Z(?ms)'