Merge pull request #3017 from amykyta3/master

Improve python3 performance by adding __slots__

Author: ericvergnaud

runtime/Python3/src/antlr4/BufferedTokenStream.py

@@ -27,6 +27,7 @@ class TokenStream(object):
 
 
 class BufferedTokenStream(TokenStream):
+    __slots__ = ('tokenSource', 'tokens', 'index', 'fetchedEOF')
 
     def __init__(self, tokenSource:Lexer):
         # The {@link TokenSource} from which tokens for this stream are fetched.

runtime/Python3/src/antlr4/CommonTokenFactory.py

@@ -15,6 +15,8 @@ class TokenFactory(object):
     pass
 
 class CommonTokenFactory(TokenFactory):
+    __slots__ = 'copyText'
+
     #
     # The default {@link CommonTokenFactory} instance.
     #
@@ -56,4 +58,4 @@ def createThin(self, type:int, text:str):
         t.text = text
         return t
 
-CommonTokenFactory.DEFAULT = CommonTokenFactory()
+CommonTokenFactory.DEFAULT = CommonTokenFactory()

runtime/Python3/src/antlr4/CommonTokenStream.py

@@ -35,6 +35,7 @@
 
 
 class CommonTokenStream(BufferedTokenStream):
+    __slots__ = 'channel'
 
     def __init__(self, lexer:Lexer, channel:int=Token.DEFAULT_CHANNEL):
         super().__init__(lexer)

runtime/Python3/src/antlr4/FileStream.py

@@ -14,6 +14,7 @@
 
 
 class FileStream(InputStream):
+    __slots__ = 'fileName'
 
     def __init__(self, fileName:str, encoding:str='ascii', errors:str='strict'):
         super().__init__(self.readDataFrom(fileName, encoding, errors))

runtime/Python3/src/antlr4/InputStream.py

@@ -12,6 +12,7 @@
 
 
 class InputStream (object):
+    __slots__ = ('name', 'strdata', '_index', 'data', '_size')
 
     def __init__(self, data: str):
         self.name = "<empty>"

runtime/Python3/src/antlr4/IntervalSet.py

@@ -11,6 +11,7 @@
 IntervalSet = None
 
 class IntervalSet(object):
+    __slots__ = ('intervals', 'readOnly')
 
     def __init__(self):
         self.intervals = None

runtime/Python3/src/antlr4/LL1Analyzer.py

@@ -14,6 +14,7 @@
 
 
 class LL1Analyzer (object):
+    __slots__ = 'atn'
 
     #* Special value added to the lookahead sets to indicate that we hit
     #  a predicate during analysis if {@code seeThruPreds==false}.

runtime/Python3/src/antlr4/Lexer.py

@@ -28,6 +28,11 @@ class TokenSource(object):
 
 
 class Lexer(Recognizer, TokenSource):
+    __slots__ = (
+        '_input', '_output', '_factory', '_tokenFactorySourcePair', '_token',
+        '_tokenStartCharIndex', '_tokenStartLine', '_tokenStartColumn',
+        '_hitEOF', '_channel', '_type', '_modeStack', '_mode', '_text'
+    )
 
     DEFAULT_MODE = 0
     MORE = -2
@@ -322,4 +327,3 @@ def recover(self, re:RecognitionException):
             else:
                 # TODO: Do we lose character or line position information?
                 self._input.consume()
-

runtime/Python3/src/antlr4/ListTokenSource.py

@@ -18,6 +18,7 @@
 
 
 class ListTokenSource(TokenSource):
+    __slots__ = ('tokens', 'sourceName', 'pos', 'eofToken', '_factory')
 
     # Constructs a new {@link ListTokenSource} instance from the specified
     # collection of {@link Token} objects and source name.
@@ -140,4 +141,4 @@ def getSourceName(self):
         if inputStream is not None:
             return inputStream.getSourceName()
         else:
-            return "List"
+            return "List"

runtime/Python3/src/antlr4/Parser.py

@@ -23,6 +23,7 @@
 from antlr4.tree.Tree import ParseTreeListener, TerminalNode, ErrorNode
 
 class TraceListener(ParseTreeListener):
+    __slots__ = '_parser'
 
     def __init__(self, parser):
         self._parser = parser
@@ -44,7 +45,11 @@ def exitEveryRule(self, ctx):
 
 # self is all the parsing support code essentially; most of it is error recovery stuff.#
 class Parser (Recognizer):
+    __slots__ = (
+        '_input', '_output', '_errHandler', '_precedenceStack', '_ctx',
+        'buildParseTrees', '_tracer', '_parseListeners', '_syntaxErrors'
 
+    )
     # self field maps from the serialized ATN string to the deserialized {@link ATN} with
     # bypass alternatives.
     #