Moved gencodec.py to the Tools/unicode/ directory.

Added new support for decoding tables.

Cleaned up the implementation a bit.

1 files changed, 391 insertions, 0 deletions

diff --git a/Tools/unicode/gencodec.py b/Tools/unicode/gencodec.py
new file mode 100644
index 0000000..7bce3d5
--- /dev/null
+++ b/Tools/unicode/gencodec.py
@@ -0,0 +1,391 @@
+""" Unicode Mapping Parser and Codec Generator.
+
+This script parses Unicode mapping files as available from the Unicode
+site (ftp://ftp.unicode.org/Public/MAPPINGS/) and creates Python codec
+modules from them. The codecs use the standard character mapping codec
+to actually apply the mapping.
+
+Synopsis: gencodec.py dir codec_prefix
+
+All files in dir are scanned and those producing non-empty mappings
+will be written to <codec_prefix><mapname>.py with <mapname> being the
+first part of the map's filename ('a' in a.b.c.txt) converted to
+lowercase with hyphens replaced by underscores.
+
+The tool also writes marshalled versions of the mapping tables to the
+same location (with .mapping extension).
+
+Written by Marc-Andre Lemburg (mal@lemburg.com).  Modified to generate
+Unicode table maps for decoding.
+
+(c) Copyright CNRI, All Rights Reserved. NO WARRANTY.
+(c) Copyright Guido van Rossum, 2000.
+(c) Copyright Marc-Andre Lemburg, 2005.
+
+"""#"
+
+import re, os, time, marshal, codecs
+
+# Maximum allowed size of charmap tables
+MAX_TABLE_SIZE = 8192
+
+# Standard undefined Unicode code point
+UNI_UNDEFINED = unichr(0xFFFE)
+
+mapRE = re.compile('((?:0x[0-9a-fA-F]+\+?)+)'
+                   '\s+'
+                   '((?:(?:0x[0-9a-fA-Z]+|<[A-Za-z]+>)\+?)*)'
+                   '\s*'
+                   '(#.+)?')
+
+def parsecodes(codes,
+               len=len, filter=filter,range=range):
+
+    """ Converts code combinations to either a single code integer
+        or a tuple of integers.
+
+        meta-codes (in angular brackets, e.g. <LR> and <RL>) are
+        ignored.
+
+        Empty codes or illegal ones are returned as None.
+
+    """
+    if not codes:
+        return None
+    l = codes.split('+')
+    if len(l) == 1:
+        return int(l[0],16)
+    for i in range(len(l)):
+        try:
+            l[i] = int(l[i],16)
+        except ValueError:
+            l[i] = None
+    l = filter(lambda x: x is not None, l)
+    if len(l) == 1:
+        return l[0]
+    else:
+        return tuple(l)
+
+def readmap(filename):
+
+    f = open(filename,'r')
+    lines = f.readlines()
+    f.close()
+    enc2uni = {}
+    identity = []
+    unmapped = range(256)
+
+    # UTC mapping tables per convention don't include the identity
+    # mappings for code points 0x00 - 0x1F and 0x7F, unless these are
+    # explicitly mapped to different characters or undefined
+    for i in range(32) + [127]:
+        identity.append(i)
+        unmapped.remove(i)
+        enc2uni[i] = (i, 'CONTROL CHARACTER')
+
+    for line in lines:
+        line = line.strip()
+        if not line or line[0] == '#':
+            continue
+        m = mapRE.match(line)
+        if not m:
+            #print '* not matched: %s' % repr(line)
+            continue
+        enc,uni,comment = m.groups()
+        enc = parsecodes(enc)
+        uni = parsecodes(uni)
+        if comment is None:
+            comment = ''
+        else:
+            comment = comment[1:].strip()
+        if enc < 256:
+            if enc in unmapped:
+                unmapped.remove(enc)
+            if enc == uni:
+                identity.append(enc)
+            enc2uni[enc] = (uni,comment)
+        else:
+            enc2uni[enc] = (uni,comment)
+
+    # If there are more identity-mapped entries than unmapped entries,
+    # it pays to generate an identity dictionary first, and add explicit
+    # mappings to None for the rest
+    if len(identity) >= len(unmapped):
+        for enc in unmapped:
+            enc2uni[enc] = (None, "")
+        enc2uni['IDENTITY'] = 256
+
+    return enc2uni
+
+def hexrepr(t):
+
+    if t is None:
+        return 'None'
+    try:
+        len(t)
+    except:
+        return '0x%04x' % t
+    try:
+        return '(' + ', '.join(map(lambda t: '0x%04x' % t, t)) + ')'
+    except TypeError, why:
+        print '* failed to convert %r: %s' % (t, why)
+        raise
+
+def python_mapdef_code(varname, map, comments=1):
+
+    l = []
+    append = l.append
+    if map.has_key("IDENTITY"):
+        append("%s = codecs.make_identity_dict(range(%d))" %
+               (varname, map["IDENTITY"]))
+        append("%s.update({" % varname)
+        splits = 1
+        del map["IDENTITY"]
+        identity = 1
+    else:
+        append("%s = {" % varname)
+        splits = 0
+        identity = 0
+
+    mappings = map.items()
+    mappings.sort()
+    i = 0
+    for mapkey, mapvalue in mappings:
+        mapcomment = ''
+        if isinstance(mapkey, tuple):
+            (mapkey, mapcomment) = mapkey
+        if isinstance(mapvalue, tuple):
+            (mapvalue, mapcomment) = mapvalue
+        if mapkey is None:
+            continue
+        if (identity and
+            mapkey == mapvalue and
+            mapkey < 256):
+            # No need to include identity mappings, since these
+            # are already set for the first 256 code points.
+            continue
+        key = hexrepr(mapkey)
+        value = hexrepr(mapvalue)
+        if mapcomment and comments:
+            append('    %s: %s,\t#  %s' % (key, value, mapcomment))
+        else:
+            append('    %s: %s,' % (key, value))
+        i += 1
+        if i == 4096:
+            # Split the definition into parts to that the Python
+            # parser doesn't dump core
+            if splits == 0:
+                append('}')
+            else:
+                append('})')
+            append('%s.update({' % varname)
+            i = 0
+            splits = splits + 1
+    if splits == 0:
+        append('}')
+    else:
+        append('})')
+
+    return l
+
+def python_tabledef_code(varname, map, comments=1):
+
+    l = []
+    append = l.append
+    append('%s = (' % varname)
+
+    # Analyze map and create table dict
+    mappings = map.items()
+    mappings.sort()
+    table = {}
+    maxkey = 0
+    if map.has_key('IDENTITY'):
+        for key in range(256):
+            table[key] = (key, '')
+        maxkey = 255
+        del map['IDENTITY']
+    for mapkey, mapvalue in mappings:
+        mapcomment = ''
+        if isinstance(mapkey, tuple):
+            (mapkey, mapcomment) = mapkey
+        if isinstance(mapvalue, tuple):
+            (mapvalue, mapcomment) = mapvalue
+        if mapkey is None:
+            continue
+        table[mapkey] = (mapvalue, mapcomment)
+        if mapkey > maxkey:
+            maxkey = mapkey
+    if maxkey > MAX_TABLE_SIZE:
+        # Table too large
+        return None
+
+    # Create table code
+    for key in range(maxkey + 1):
+        if key not in table:
+            mapvalue = None
+            mapcomment = 'UNDEFINED'
+        else:
+            mapvalue, mapcomment = table[key]
+        if mapvalue is None:
+            mapchar = UNI_UNDEFINED
+        else:
+            if isinstance(mapvalue, tuple):
+                # 1-n mappings not supported
+                return None
+            else:
+                mapchar = unichr(mapvalue)
+        if mapcomment and comments:
+            append('    %r\t#  %s -> %s' % (mapchar,
+                                            hexrepr(key),
+                                            mapcomment))
+        else:
+            append('    %r' % mapchar)
+
+    append(')')
+    return l
+
+def codegen(name, map, comments=1):
+
+    """ Returns Python source for the given map.
+
+        Comments are included in the source, if comments is true (default).
+
+    """
+    # Generate code
+    decoding_map_code = python_mapdef_code(
+        'decoding_map',
+        map,
+        comments=comments)
+    decoding_table_code = python_tabledef_code(
+        'decoding_table',
+        map,
+        comments=comments)
+    encoding_map_code = python_mapdef_code(
+        'encoding_map',
+        codecs.make_encoding_map(map),
+        comments=comments)
+
+    l = [
+        '''\
+""" Python Character Mapping Codec generated from '%s' with gencodec.py.
+
+"""#"
+
+import codecs
+
+### Codec APIs
+
+class Codec(codecs.Codec):
+
+    def encode(self,input,errors='strict'):
+
+        return codecs.charmap_encode(input,errors,encoding_map)
+
+    def decode(self,input,errors='strict'):
+''' % name
+        ]
+    if decoding_table_code:
+        l.append('''\
+        return codecs.charmap_decode(input,errors,decoding_table)''')
+    else:
+        l.append('''\
+        return codecs.charmap_decode(input,errors,decoding_map)''')
+         
+    l.append('''    
+class StreamWriter(Codec,codecs.StreamWriter):
+    pass
+
+class StreamReader(Codec,codecs.StreamReader):
+    pass
+
+### encodings module API
+
+def getregentry():
+
+    return (Codec().encode,Codec().decode,StreamReader,StreamWriter)
+
+### Decoding Map
+''')
+    l.extend(decoding_map_code)
+
+    # Add optional decoding table
+    if decoding_table_code:
+        l.append('''
+### Decoding Table
+''')
+        l.extend(decoding_table_code)
+
+    l.append('''
+### Encoding Map
+''')
+    l.extend(encoding_map_code)
+    
+    return '\n'.join(l)
+
+def pymap(name,map,pyfile,comments=1):
+
+    code = codegen(name,map,comments)
+    f = open(pyfile,'w')
+    f.write(code)
+    f.close()
+
+def marshalmap(name,map,marshalfile):
+
+    d = {}
+    for e,(u,c) in map.items():
+        d[e] = (u,c)
+    f = open(marshalfile,'wb')
+    marshal.dump(d,f)
+    f.close()
+
+def convertdir(dir,prefix='',comments=1):
+
+    mapnames = os.listdir(dir)
+    for mapname in mapnames:
+        mappathname = os.path.join(dir, mapname)
+        name = os.path.split(mapname)[1]
+        name = name.replace('-','_')
+        name = name.split('.')[0]
+        name = name.lower()
+        codefile = name + '.py'
+        marshalfile = name + '.mapping'
+        print 'converting %s to %s and %s' % (mapname,
+                                              prefix + codefile,
+                                              prefix + marshalfile)
+        try:
+            map = readmap(os.path.join(dir,mapname))
+            if not map:
+                print '* map is empty; skipping'
+            else:
+                pymap(mappathname, map, prefix + codefile,comments)
+                marshalmap(mappathname, map, prefix + marshalfile)
+        except ValueError, why:
+            print '* conversion failed: %s' % why
+            raise
+
+def rewritepythondir(dir,prefix='',comments=1):
+
+    mapnames = os.listdir(dir)
+    for mapname in mapnames:
+        if not mapname.endswith('.mapping'):
+            continue
+        codefile = mapname[:-len('.mapping')] + '.py'
+        print 'converting %s to %s' % (mapname,
+                                       prefix + codefile)
+        try:
+            map = marshal.load(open(os.path.join(dir,mapname),
+                               'rb'))
+            if not map:
+                print '* map is empty; skipping'
+            else:
+                pymap(mapname, map, prefix + codefile,comments)
+        except ValueError, why:
+            print '* conversion failed: %s' % why
+
+if __name__ == '__main__':
+
+    import sys
+    if 1:
+        apply(convertdir,tuple(sys.argv[1:]))
+    else:
+        apply(rewritepythondir,tuple(sys.argv[1:]))