Merged revisions 61596-61597 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk
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r61596 | martin.v.loewis | 2008-03-18 23:43:46 -0500 (Di, 18 Mär 2008) | 2 lines
Import lib2to3.
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r61597 | martin.v.loewis | 2008-03-18 23:58:04 -0500 (Di, 18 Mär 2008) | 3 lines
Initialized merge tracking via "svnmerge" with revisions "1-61595" from
svn+ssh://pythondev@svn.python.org/sandbox/trunk/2to3/lib2to3
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diff --git a/Lib/lib2to3/pgen2/driver.py b/Lib/lib2to3/pgen2/driver.py
new file mode 100644
index 0000000..77e2a40
--- /dev/null
+++ b/Lib/lib2to3/pgen2/driver.py
@@ -0,0 +1,143 @@
+# Copyright 2004-2005 Elemental Security, Inc. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+# Modifications:
+# Copyright 2006 Google, Inc. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+"""Parser driver.
+
+This provides a high-level interface to parse a file into a syntax tree.
+
+"""
+
+__author__ = "Guido van Rossum <guido@python.org>"
+
+__all__ = ["Driver", "load_grammar"]
+
+# Python imports
+import os
+import logging
+import sys
+
+# Pgen imports
+from . import grammar, parse, token, tokenize
+
+
+class Driver(object):
+
+ def __init__(self, grammar, convert=None, logger=None):
+ self.grammar = grammar
+ if logger is None:
+ logger = logging.getLogger()
+ self.logger = logger
+ self.convert = convert
+
+ def parse_tokens(self, tokens, debug=False):
+ """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()
+ lineno = 1
+ column = 0
+ type = value = start = end = line_text = None
+ prefix = ""
+ for quintuple in tokens:
+ type, value, start, end, line_text = quintuple
+ if start != (lineno, column):
+ assert (lineno, column) <= start, ((lineno, column), start)
+ s_lineno, s_column = start
+ if lineno < s_lineno:
+ prefix += "\n" * (s_lineno - lineno)
+ lineno = s_lineno
+ column = 0
+ if column < s_column:
+ prefix += line_text[column:s_column]
+ column = s_column
+ if type in (tokenize.COMMENT, tokenize.NL):
+ prefix += value
+ lineno, column = end
+ if value.endswith("\n"):
+ lineno += 1
+ column = 0
+ continue
+ if type == token.OP:
+ type = grammar.opmap[value]
+ if debug:
+ self.logger.debug("%s %r (prefix=%r)",
+ token.tok_name[type], value, prefix)
+ if p.addtoken(type, value, (prefix, start)):
+ if debug:
+ self.logger.debug("Stop.")
+ break
+ prefix = ""
+ lineno, column = end
+ if value.endswith("\n"):
+ lineno += 1
+ column = 0
+ else:
+ # We never broke out -- EOF is too soon (how can this happen???)
+ raise parse.ParseError("incomplete input", t, v, x)
+ return p.rootnode
+
+ def parse_stream_raw(self, stream, debug=False):
+ """Parse a stream and return the syntax tree."""
+ tokens = tokenize.generate_tokens(stream.readline)
+ return self.parse_tokens(tokens, debug)
+
+ def parse_stream(self, stream, debug=False):
+ """Parse a stream and return the syntax tree."""
+ return self.parse_stream_raw(stream, debug)
+
+ def parse_file(self, filename, debug=False):
+ """Parse a file and return the syntax tree."""
+ stream = open(filename)
+ try:
+ return self.parse_stream(stream, debug)
+ finally:
+ stream.close()
+
+ def parse_string(self, text, debug=False):
+ """Parse a string and return the syntax tree."""
+ tokens = tokenize.generate_tokens(generate_lines(text).next)
+ return self.parse_tokens(tokens, debug)
+
+
+def generate_lines(text):
+ """Generator that behaves like readline without using StringIO."""
+ for line in text.splitlines(True):
+ yield line
+ while True:
+ yield ""
+
+
+def load_grammar(gt="Grammar.txt", gp=None,
+ save=True, force=False, logger=None):
+ """Load the grammar (maybe from a pickle)."""
+ if logger is None:
+ logger = logging.getLogger()
+ if gp is None:
+ head, tail = os.path.splitext(gt)
+ if tail == ".txt":
+ tail = ""
+ gp = head + tail + ".".join(map(str, sys.version_info)) + ".pickle"
+ if force or not _newer(gp, gt):
+ logger.info("Generating grammar tables from %s", gt)
+ from pgen2 import pgen
+ g = pgen.generate_grammar(gt)
+ if save:
+ logger.info("Writing grammar tables to %s", gp)
+ g.dump(gp)
+ else:
+ g = grammar.Grammar()
+ g.load(gp)
+ return g
+
+
+def _newer(a, b):
+ """Inquire whether file a was written since file b."""
+ if not os.path.exists(a):
+ return False
+ if not os.path.exists(b):
+ return True
+ return os.path.getmtime(a) >= os.path.getmtime(b)