python-3.6.zip added from Github

README.cosmo contains the necessary links.

third_party/python/Lib/encodings/punycode.py

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+""" Codec for the Punicode encoding, as specified in RFC 3492
+
+Written by Martin v. Löwis.
+"""
+
+import codecs
+
+##################### Encoding #####################################
+
+def segregate(str):
+    """3.1 Basic code point segregation"""
+    base = bytearray()
+    extended = set()
+    for c in str:
+        if ord(c) < 128:
+            base.append(ord(c))
+        else:
+            extended.add(c)
+    extended = sorted(extended)
+    return bytes(base), extended
+
+def selective_len(str, max):
+    """Return the length of str, considering only characters below max."""
+    res = 0
+    for c in str:
+        if ord(c) < max:
+            res += 1
+    return res
+
+def selective_find(str, char, index, pos):
+    """Return a pair (index, pos), indicating the next occurrence of
+    char in str. index is the position of the character considering
+    only ordinals up to and including char, and pos is the position in
+    the full string. index/pos is the starting position in the full
+    string."""
+
+    l = len(str)
+    while 1:
+        pos += 1
+        if pos == l:
+            return (-1, -1)
+        c = str[pos]
+        if c == char:
+            return index+1, pos
+        elif c < char:
+            index += 1
+
+def insertion_unsort(str, extended):
+    """3.2 Insertion unsort coding"""
+    oldchar = 0x80
+    result = []
+    oldindex = -1
+    for c in extended:
+        index = pos = -1
+        char = ord(c)
+        curlen = selective_len(str, char)
+        delta = (curlen+1) * (char - oldchar)
+        while 1:
+            index,pos = selective_find(str,c,index,pos)
+            if index == -1:
+                break
+            delta += index - oldindex
+            result.append(delta-1)
+            oldindex = index
+            delta = 0
+        oldchar = char
+
+    return result
+
+def T(j, bias):
+    # Punycode parameters: tmin = 1, tmax = 26, base = 36
+    res = 36 * (j + 1) - bias
+    if res < 1: return 1
+    if res > 26: return 26
+    return res
+
+digits = b"abcdefghijklmnopqrstuvwxyz0123456789"
+def generate_generalized_integer(N, bias):
+    """3.3 Generalized variable-length integers"""
+    result = bytearray()
+    j = 0
+    while 1:
+        t = T(j, bias)
+        if N < t:
+            result.append(digits[N])
+            return bytes(result)
+        result.append(digits[t + ((N - t) % (36 - t))])
+        N = (N - t) // (36 - t)
+        j += 1
+
+def adapt(delta, first, numchars):
+    if first:
+        delta //= 700
+    else:
+        delta //= 2
+    delta += delta // numchars
+    # ((base - tmin) * tmax) // 2 == 455
+    divisions = 0
+    while delta > 455:
+        delta = delta // 35 # base - tmin
+        divisions += 36
+    bias = divisions + (36 * delta // (delta + 38))
+    return bias
+
+
+def generate_integers(baselen, deltas):
+    """3.4 Bias adaptation"""
+    # Punycode parameters: initial bias = 72, damp = 700, skew = 38
+    result = bytearray()
+    bias = 72
+    for points, delta in enumerate(deltas):
+        s = generate_generalized_integer(delta, bias)
+        result.extend(s)
+        bias = adapt(delta, points==0, baselen+points+1)
+    return bytes(result)
+
+def punycode_encode(text):
+    base, extended = segregate(text)
+    deltas = insertion_unsort(text, extended)
+    extended = generate_integers(len(base), deltas)
+    if base:
+        return base + b"-" + extended
+    return extended
+
+##################### Decoding #####################################
+
+def decode_generalized_number(extended, extpos, bias, errors):
+    """3.3 Generalized variable-length integers"""
+    result = 0
+    w = 1
+    j = 0
+    while 1:
+        try:
+            char = ord(extended[extpos])
+        except IndexError:
+            if errors == "strict":
+                raise UnicodeError("incomplete punicode string")
+            return extpos + 1, None
+        extpos += 1
+        if 0x41 <= char <= 0x5A: # A-Z
+            digit = char - 0x41
+        elif 0x30 <= char <= 0x39:
+            digit = char - 22 # 0x30-26
+        elif errors == "strict":
+            raise UnicodeError("Invalid extended code point '%s'"
+                               % extended[extpos])
+        else:
+            return extpos, None
+        t = T(j, bias)
+        result += digit * w
+        if digit < t:
+            return extpos, result
+        w = w * (36 - t)
+        j += 1
+
+
+def insertion_sort(base, extended, errors):
+    """3.2 Insertion unsort coding"""
+    char = 0x80
+    pos = -1
+    bias = 72
+    extpos = 0
+    while extpos < len(extended):
+        newpos, delta = decode_generalized_number(extended, extpos,
+                                                  bias, errors)
+        if delta is None:
+            # There was an error in decoding. We can't continue because
+            # synchronization is lost.
+            return base
+        pos += delta+1
+        char += pos // (len(base) + 1)
+        if char > 0x10FFFF:
+            if errors == "strict":
+                raise UnicodeError("Invalid character U+%x" % char)
+            char = ord('?')
+        pos = pos % (len(base) + 1)
+        base = base[:pos] + chr(char) + base[pos:]
+        bias = adapt(delta, (extpos == 0), len(base))
+        extpos = newpos
+    return base
+
+def punycode_decode(text, errors):
+    if isinstance(text, str):
+        text = text.encode("ascii")
+    if isinstance(text, memoryview):
+        text = bytes(text)
+    pos = text.rfind(b"-")
+    if pos == -1:
+        base = ""
+        extended = str(text, "ascii").upper()
+    else:
+        base = str(text[:pos], "ascii", errors)
+        extended = str(text[pos+1:], "ascii").upper()
+    return insertion_sort(base, extended, errors)
+
+### Codec APIs
+
+class Codec(codecs.Codec):
+
+    def encode(self, input, errors='strict'):
+        res = punycode_encode(input)
+        return res, len(input)
+
+    def decode(self, input, errors='strict'):
+        if errors not in ('strict', 'replace', 'ignore'):
+            raise UnicodeError("Unsupported error handling "+errors)
+        res = punycode_decode(input, errors)
+        return res, len(input)
+
+class IncrementalEncoder(codecs.IncrementalEncoder):
+    def encode(self, input, final=False):
+        return punycode_encode(input)
+
+class IncrementalDecoder(codecs.IncrementalDecoder):
+    def decode(self, input, final=False):
+        if self.errors not in ('strict', 'replace', 'ignore'):
+            raise UnicodeError("Unsupported error handling "+self.errors)
+        return punycode_decode(input, self.errors)
+
+class StreamWriter(Codec,codecs.StreamWriter):
+    pass
+
+class StreamReader(Codec,codecs.StreamReader):
+    pass
+
+### encodings module API
+
+def getregentry():
+    return codecs.CodecInfo(
+        name='punycode',
+        encode=Codec().encode,
+        decode=Codec().decode,
+        incrementalencoder=IncrementalEncoder,
+        incrementaldecoder=IncrementalDecoder,
+        streamwriter=StreamWriter,
+        streamreader=StreamReader,
+    )