python · pablogsal · May 21, 2023 · May 21, 2023
@@ -56,6 +56,107 @@ def exact_type(self):
         else:
             return self.type
 
+def group(*choices): return '(' + '|'.join(choices) + ')'
+def any(*choices): return group(*choices) + '*'
+def maybe(*choices): return group(*choices) + '?'
+
+# Note: we use unicode matching for names ("\w") but ascii matching for
+# number literals.
+Whitespace = r'[ \f\t]*'
+Comment = r'#[^\r\n]*'
+Ignore = Whitespace + any(r'\\\r?\n' + Whitespace) + maybe(Comment)
+Name = r'\w+'
+
+Hexnumber = r'0[xX](?:_?[0-9a-fA-F])+'
+Binnumber = r'0[bB](?:_?[01])+'
+Octnumber = r'0[oO](?:_?[0-7])+'
+Decnumber = r'(?:0(?:_?0)*|[1-9](?:_?[0-9])*)'
+Intnumber = group(Hexnumber, Binnumber, Octnumber, Decnumber)
+Exponent = r'[eE][-+]?[0-9](?:_?[0-9])*'
+Pointfloat = group(r'[0-9](?:_?[0-9])*\.(?:[0-9](?:_?[0-9])*)?',
+                   r'\.[0-9](?:_?[0-9])*') + maybe(Exponent)
+Expfloat = r'[0-9](?:_?[0-9])*' + Exponent
+Floatnumber = group(Pointfloat, Expfloat)
+Imagnumber = group(r'[0-9](?:_?[0-9])*[jJ]', Floatnumber + r'[jJ]')
+Number = group(Imagnumber, Floatnumber, Intnumber)
+
+# Return the empty string, plus all of the valid string prefixes.
+def _all_string_prefixes():
+    # The valid string prefixes. Only contain the lower case versions,
+    #  and don't contain any permutations (include 'fr', but not
+    #  'rf'). The various permutations will be generated.
+    _valid_string_prefixes = ['b', 'r', 'u', 'f', 'br', 'fr']
+    # if we add binary f-strings, add: ['fb', 'fbr']
+    result = {''}
+    for prefix in _valid_string_prefixes:
+        for t in _itertools.permutations(prefix):
+            # create a list with upper and lower versions of each
+            #  character
+            for u in _itertools.product(*[(c, c.upper()) for c in t]):
+                result.add(''.join(u))
+    return result
+
+@functools.lru_cache
+def _compile(expr):
+    return re.compile(expr, re.UNICODE)
+
+# Note that since _all_string_prefixes includes the empty string,
+#  StringPrefix can be the empty string (making it optional).
+StringPrefix = group(*_all_string_prefixes())
+
+# Tail end of ' string.
+Single = r"[^'\\]*(?:\\.[^'\\]*)*'"
+# Tail end of " string.
+Double = r'[^"\\]*(?:\\.[^"\\]*)*"'
+# Tail end of ''' string.
+Single3 = r"[^'\\]*(?:(?:\\.|'(?!''))[^'\\]*)*'''"
+# Tail end of """ string.
+Double3 = r'[^"\\]*(?:(?:\\.|"(?!""))[^"\\]*)*"""'
+Triple = group(StringPrefix + "'''", StringPrefix + '"""')
+# Single-line ' or " string.
+String = group(StringPrefix + r"'[^\n'\\]*(?:\\.[^\n'\\]*)*'",
+               StringPrefix + r'"[^\n"\\]*(?:\\.[^\n"\\]*)*"')
+
+# Sorting in reverse order puts the long operators before their prefixes.
+# Otherwise if = came before ==, == would get recognized as two instances
+# of =.
+Special = group(*map(re.escape, sorted(EXACT_TOKEN_TYPES, reverse=True)))
+Funny = group(r'\r?\n', Special)
+
+PlainToken = group(Number, Funny, String, Name)
+Token = Ignore + PlainToken
+
+# First (or only) line of ' or " string.
+ContStr = group(StringPrefix + r"'[^\n'\\]*(?:\\.[^\n'\\]*)*" +
+                group("'", r'\\\r?\n'),
+                StringPrefix + r'"[^\n"\\]*(?:\\.[^\n"\\]*)*' +
+                group('"', r'\\\r?\n'))
+PseudoExtras = group(r'\\\r?\n|\Z', Comment, Triple)
+PseudoToken = Whitespace + group(PseudoExtras, Number, Funny, ContStr, Name)
+
+# For a given string prefix plus quotes, endpats maps it to a regex
+#  to match the remainder of that string. _prefix can be empty, for
+#  a normal single or triple quoted string (with no prefix).
+endpats = {}
+for _prefix in _all_string_prefixes():
+    endpats[_prefix + "'"] = Single
+    endpats[_prefix + '"'] = Double
+    endpats[_prefix + "'''"] = Single3
+    endpats[_prefix + '"""'] = Double3
+del _prefix
+
+# A set of all of the single and triple quoted string prefixes,
+#  including the opening quotes.
+single_quoted = set()
+triple_quoted = set()
+for t in _all_string_prefixes():
+    for u in (t + '"', t + "'"):
+        single_quoted.add(u)
+    for u in (t + '"""', t + "'''"):
+        triple_quoted.add(u)
+del t, u
+
+tabsize = 8
 
 class TokenError(Exception): pass