]> git.madduck.net Git - etc/vim.git/blobdiff - src/blib2to3/pgen2/driver.py

madduck's git repository

Every one of the projects in this repository is available at the canonical URL git://git.madduck.net/madduck/pub/<projectpath> — see each project's metadata for the exact URL.

All patches and comments are welcome. Please squash your changes to logical commits before using git-format-patch and git-send-email to patches@git.madduck.net. If you'd read over the Git project's submission guidelines and adhered to them, I'd be especially grateful.

SSH access, as well as push access can be individually arranged.

If you use my repositories frequently, consider adding the following snippet to ~/.gitconfig and using the third clone URL listed for each project:

[url "git://git.madduck.net/madduck/"]
  insteadOf = madduck:

Apply ignore logic before symlink resolution (#3846)
[etc/vim.git] / src / blib2to3 / pgen2 / driver.py
index 052c94883cf5ae6eca9c8676d95ebc50586cd1c6..e629843f8b986ea792d59a150ff64018d2108bcb 100644 (file)
@@ -16,58 +16,116 @@ __author__ = "Guido van Rossum <guido@python.org>"
 __all__ = ["Driver", "load_grammar"]
 
 # Python imports
 __all__ = ["Driver", "load_grammar"]
 
 # Python imports
-import codecs
 import io
 import io
-import os
 import logging
 import logging
+import os
 import pkgutil
 import sys
 import pkgutil
 import sys
-from typing import (
-    Any,
-    Callable,
-    IO,
-    Iterable,
-    List,
-    Optional,
-    Text,
-    Tuple,
-    Union,
-    Sequence,
-)
-
-# Pgen imports
-from . import grammar, parse, token, tokenize, pgen
+from contextlib import contextmanager
+from dataclasses import dataclass, field
 from logging import Logger
 from logging import Logger
-from blib2to3.pytree import _Convert, NL
+from typing import IO, Any, Iterable, Iterator, List, Optional, Tuple, Union, cast
+
 from blib2to3.pgen2.grammar import Grammar
 from blib2to3.pgen2.grammar import Grammar
+from blib2to3.pgen2.tokenize import GoodTokenInfo
+from blib2to3.pytree import NL
+
+# Pgen imports
+from . import grammar, parse, pgen, token, tokenize
 
 Path = Union[str, "os.PathLike[str]"]
 
 
 
 Path = Union[str, "os.PathLike[str]"]
 
 
-class Driver(object):
-    def __init__(
-        self,
-        grammar: Grammar,
-        convert: Optional[_Convert] = None,
-        logger: Optional[Logger] = None,
-    ) -> None:
+@dataclass
+class ReleaseRange:
+    start: int
+    end: Optional[int] = None
+    tokens: List[Any] = field(default_factory=list)
+
+    def lock(self) -> None:
+        total_eaten = len(self.tokens)
+        self.end = self.start + total_eaten
+
+
+class TokenProxy:
+    def __init__(self, generator: Any) -> None:
+        self._tokens = generator
+        self._counter = 0
+        self._release_ranges: List[ReleaseRange] = []
+
+    @contextmanager
+    def release(self) -> Iterator["TokenProxy"]:
+        release_range = ReleaseRange(self._counter)
+        self._release_ranges.append(release_range)
+        try:
+            yield self
+        finally:
+            # Lock the last release range to the final position that
+            # has been eaten.
+            release_range.lock()
+
+    def eat(self, point: int) -> Any:
+        eaten_tokens = self._release_ranges[-1].tokens
+        if point < len(eaten_tokens):
+            return eaten_tokens[point]
+        else:
+            while point >= len(eaten_tokens):
+                token = next(self._tokens)
+                eaten_tokens.append(token)
+            return token
+
+    def __iter__(self) -> "TokenProxy":
+        return self
+
+    def __next__(self) -> Any:
+        # If the current position is already compromised (looked up)
+        # return the eaten token, if not just go further on the given
+        # token producer.
+        for release_range in self._release_ranges:
+            assert release_range.end is not None
+
+            start, end = release_range.start, release_range.end
+            if start <= self._counter < end:
+                token = release_range.tokens[self._counter - start]
+                break
+        else:
+            token = next(self._tokens)
+        self._counter += 1
+        return token
+
+    def can_advance(self, to: int) -> bool:
+        # Try to eat, fail if it can't. The eat operation is cached
+        # so there won't be any additional cost of eating here
+        try:
+            self.eat(to)
+        except StopIteration:
+            return False
+        else:
+            return True
+
+
+class Driver:
+    def __init__(self, grammar: Grammar, logger: Optional[Logger] = None) -> None:
         self.grammar = grammar
         if logger is None:
             logger = logging.getLogger(__name__)
         self.logger = logger
         self.grammar = grammar
         if logger is None:
             logger = logging.getLogger(__name__)
         self.logger = logger
-        self.convert = convert
 
 
-    def parse_tokens(self, tokens: Iterable[Any], debug: bool = False) -> NL:
+    def parse_tokens(self, tokens: Iterable[GoodTokenInfo], debug: bool = False) -> NL:
         """Parse a series of tokens and return the syntax tree."""
         # XXX Move the prefix computation into a wrapper around tokenize.
         """Parse a series of tokens and return the syntax tree."""
         # XXX Move the prefix computation into a wrapper around tokenize.
-        p = parse.Parser(self.grammar, self.convert)
-        p.setup()
+        proxy = TokenProxy(tokens)
+
+        p = parse.Parser(self.grammar)
+        p.setup(proxy=proxy)
+
         lineno = 1
         column = 0
         lineno = 1
         column = 0
-        indent_columns = []
+        indent_columns: List[int] = []
         type = value = start = end = line_text = None
         prefix = ""
         type = value = start = end = line_text = None
         prefix = ""
-        for quintuple in tokens:
+
+        for quintuple in proxy:
             type, value, start, end, line_text = quintuple
             if start != (lineno, column):
                 assert (lineno, column) <= start, ((lineno, column), start)
             type, value, start, end, line_text = quintuple
             if start != (lineno, column):
                 assert (lineno, column) <= start, ((lineno, column), start)
@@ -89,6 +147,7 @@ class Driver(object):
             if type == token.OP:
                 type = grammar.opmap[value]
             if debug:
             if type == token.OP:
                 type = grammar.opmap[value]
             if debug:
+                assert type is not None
                 self.logger.debug(
                     "%s %r (prefix=%r)", token.tok_name[type], value, prefix
                 )
                 self.logger.debug(
                     "%s %r (prefix=%r)", token.tok_name[type], value, prefix
                 )
@@ -100,7 +159,7 @@ class Driver(object):
             elif type == token.DEDENT:
                 _indent_col = indent_columns.pop()
                 prefix, _prefix = self._partially_consume_prefix(prefix, _indent_col)
             elif type == token.DEDENT:
                 _indent_col = indent_columns.pop()
                 prefix, _prefix = self._partially_consume_prefix(prefix, _indent_col)
-            if p.addtoken(type, value, (prefix, start)):
+            if p.addtoken(cast(int, type), value, (prefix, start)):
                 if debug:
                     self.logger.debug("Stop.")
                 break
                 if debug:
                     self.logger.debug("Stop.")
                 break
@@ -118,30 +177,30 @@ class Driver(object):
         assert p.rootnode is not None
         return p.rootnode
 
         assert p.rootnode is not None
         return p.rootnode
 
-    def parse_stream_raw(self, stream: IO[Text], debug: bool = False) -> NL:
+    def parse_stream_raw(self, stream: IO[str], debug: bool = False) -> NL:
         """Parse a stream and return the syntax tree."""
         tokens = tokenize.generate_tokens(stream.readline, grammar=self.grammar)
         return self.parse_tokens(tokens, debug)
 
         """Parse a stream and return the syntax tree."""
         tokens = tokenize.generate_tokens(stream.readline, grammar=self.grammar)
         return self.parse_tokens(tokens, debug)
 
-    def parse_stream(self, stream: IO[Text], debug: bool = False) -> NL:
+    def parse_stream(self, stream: IO[str], debug: bool = False) -> NL:
         """Parse a stream and return the syntax tree."""
         return self.parse_stream_raw(stream, debug)
 
     def parse_file(
         """Parse a stream and return the syntax tree."""
         return self.parse_stream_raw(stream, debug)
 
     def parse_file(
-        self, filename: Path, encoding: Optional[Text] = None, debug: bool = False,
+        self, filename: Path, encoding: Optional[str] = None, debug: bool = False
     ) -> NL:
         """Parse a file and return the syntax tree."""
     ) -> NL:
         """Parse a file and return the syntax tree."""
-        with io.open(filename, "r", encoding=encoding) as stream:
+        with open(filename, encoding=encoding) as stream:
             return self.parse_stream(stream, debug)
 
             return self.parse_stream(stream, debug)
 
-    def parse_string(self, text: Text, debug: bool = False) -> NL:
+    def parse_string(self, text: str, debug: bool = False) -> NL:
         """Parse a string and return the syntax tree."""
         tokens = tokenize.generate_tokens(
             io.StringIO(text).readline, grammar=self.grammar
         )
         return self.parse_tokens(tokens, debug)
 
         """Parse a string and return the syntax tree."""
         tokens = tokenize.generate_tokens(
             io.StringIO(text).readline, grammar=self.grammar
         )
         return self.parse_tokens(tokens, debug)
 
-    def _partially_consume_prefix(self, prefix: Text, column: int) -> Tuple[Text, Text]:
+    def _partially_consume_prefix(self, prefix: str, column: int) -> Tuple[str, str]:
         lines: List[str] = []
         current_line = ""
         current_column = 0
         lines: List[str] = []
         current_line = ""
         current_column = 0
@@ -169,7 +228,7 @@ class Driver(object):
         return "".join(lines), current_line
 
 
         return "".join(lines), current_line
 
 
-def _generate_pickle_name(gt: Path, cache_dir: Optional[Path] = None) -> Text:
+def _generate_pickle_name(gt: Path, cache_dir: Optional[Path] = None) -> str:
     head, tail = os.path.splitext(gt)
     if tail == ".txt":
         tail = ""
     head, tail = os.path.splitext(gt)
     if tail == ".txt":
         tail = ""
@@ -181,8 +240,8 @@ def _generate_pickle_name(gt: Path, cache_dir: Optional[Path] = None) -> Text:
 
 
 def load_grammar(
 
 
 def load_grammar(
-    gt: Text = "Grammar.txt",
-    gp: Optional[Text] = None,
+    gt: str = "Grammar.txt",
+    gp: Optional[str] = None,
     save: bool = True,
     force: bool = False,
     logger: Optional[Logger] = None,
     save: bool = True,
     force: bool = False,
     logger: Optional[Logger] = None,
@@ -192,21 +251,20 @@ def load_grammar(
         logger = logging.getLogger(__name__)
     gp = _generate_pickle_name(gt) if gp is None else gp
     if force or not _newer(gp, gt):
         logger = logging.getLogger(__name__)
     gp = _generate_pickle_name(gt) if gp is None else gp
     if force or not _newer(gp, gt):
-        logger.info("Generating grammar tables from %s", gt)
         g: grammar.Grammar = pgen.generate_grammar(gt)
         if save:
         g: grammar.Grammar = pgen.generate_grammar(gt)
         if save:
-            logger.info("Writing grammar tables to %s", gp)
             try:
                 g.dump(gp)
             try:
                 g.dump(gp)
-            except OSError as e:
-                logger.info("Writing failed: %s", e)
+            except OSError:
+                # Ignore error, caching is not vital.
+                pass
     else:
         g = grammar.Grammar()
         g.load(gp)
     return g
 
 
     else:
         g = grammar.Grammar()
         g.load(gp)
     return g
 
 
-def _newer(a: Text, b: Text) -> bool:
+def _newer(a: str, b: str) -> bool:
     """Inquire whether file a was written since file b."""
     if not os.path.exists(a):
         return False
     """Inquire whether file a was written since file b."""
     if not os.path.exists(a):
         return False
@@ -216,7 +274,7 @@ def _newer(a: Text, b: Text) -> bool:
 
 
 def load_packaged_grammar(
 
 
 def load_packaged_grammar(
-    package: str, grammar_source: Text, cache_dir: Optional[Path] = None
+    package: str, grammar_source: str, cache_dir: Optional[Path] = None
 ) -> grammar.Grammar:
     """Normally, loads a pickled grammar by doing
         pkgutil.get_data(package, pickled_grammar)
 ) -> grammar.Grammar:
     """Normally, loads a pickled grammar by doing
         pkgutil.get_data(package, pickled_grammar)
@@ -239,7 +297,7 @@ def load_packaged_grammar(
     return g
 
 
     return g
 
 
-def main(*args: Text) -> bool:
+def main(*args: str) -> bool:
     """Main program, when run as a script: produce grammar pickle files.
 
     Calls load_grammar for each argument, a path to a grammar text file.
     """Main program, when run as a script: produce grammar pickle files.
 
     Calls load_grammar for each argument, a path to a grammar text file.