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Diffstat (limited to 'Lib/regex_syntax.py')
| -rw-r--r-- | Lib/regex_syntax.py | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/Lib/regex_syntax.py b/Lib/regex_syntax.py new file mode 100644 index 0000000..bb80f4e --- /dev/null +++ b/Lib/regex_syntax.py @@ -0,0 +1,41 @@ +# These bits are passed to regex.set_syntax() to choose among +# alternative regexp syntaxes. + +# 1 means plain parentheses serve as grouping, and backslash +# parentheses are needed for literal searching. +# 0 means backslash-parentheses are grouping, and plain parentheses +# are for literal searching. +RE_NO_BK_PARENS = 1 + +# 1 means plain | serves as the "or"-operator, and \| is a literal. +# 0 means \| serves as the "or"-operator, and | is a literal. +RE_NO_BK_VBAR = 2 + +# 0 means plain + or ? serves as an operator, and \+, \? are literals. +# 1 means \+, \? are operators and plain +, ? are literals. +RE_BK_PLUS_QM = 4 + +# 1 means | binds tighter than ^ or $. +# 0 means the contrary. +RE_TIGHT_VBAR = 8 + +# 1 means treat \n as an _OR operator +# 0 means treat it as a normal character +RE_NEWLINE_OR = 16 + +# 0 means that a special characters (such as *, ^, and $) always have +# their special meaning regardless of the surrounding context. +# 1 means that special characters may act as normal characters in some +# contexts. Specifically, this applies to: +# ^ - only special at the beginning, or after ( or | +# $ - only special at the end, or before ) or | +# *, +, ? - only special when not after the beginning, (, or | +RE_CONTEXT_INDEP_OPS = 32 + +# Now define combinations of bits for the standard possibilities. +RE_SYNTAX_AWK = (RE_NO_BK_PARENS | RE_NO_BK_VBAR | RE_CONTEXT_INDEP_OPS) +RE_SYNTAX_EGREP = (RE_SYNTAX_AWK | RE_NEWLINE_OR) +RE_SYNTAX_GREP = (RE_BK_PLUS_QM | RE_NEWLINE_OR) +RE_SYNTAX_EMACS = 0 + +# (Python's obsolete "regexp" module used a syntax similar to awk.) |