cpython/Lib/lib2to3/PatternGrammar.txt
Martin v. Löwis ef04c44e29 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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2008-03-19 05:04:44 +00:00

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# Copyright 2006 Google, Inc. All Rights Reserved.
# Licensed to PSF under a Contributor Agreement.
# A grammar to describe tree matching patterns.
# Not shown here:
# - 'TOKEN' stands for any token (leaf node)
# - 'any' stands for any node (leaf or interior)
# With 'any' we can still specify the sub-structure.
# The start symbol is 'Matcher'.
Matcher: Alternatives ENDMARKER
Alternatives: Alternative ('|' Alternative)*
Alternative: (Unit | NegatedUnit)+
Unit: [NAME '='] ( STRING [Repeater]
| NAME [Details] [Repeater]
| '(' Alternatives ')' [Repeater]
| '[' Alternatives ']'
)
NegatedUnit: 'not' (STRING | NAME [Details] | '(' Alternatives ')')
Repeater: '*' | '+' | '{' NUMBER [',' NUMBER] '}'
Details: '<' Alternatives '>'