Lib/dos-8x3/regex_sy.py

   1 # These bits are passed to regex.set_syntax() to choose among
   2 # alternative regexp syntaxes.
   3
   4 # 1 means plain parentheses serve as grouping, and backslash
   5 #   parentheses are needed for literal searching.
   6 # 0 means backslash-parentheses are grouping, and plain parentheses
   7 #   are for literal searching.
   8 RE_NO_BK_PARENS = 1
   9
  10 # 1 means plain | serves as the "or"-operator, and \| is a literal.
  11 # 0 means \| serves as the "or"-operator, and | is a literal.
  12 RE_NO_BK_VBAR = 2
  13
  14 # 0 means plain + or ? serves as an operator, and \+, \? are literals.
  15 # 1 means \+, \? are operators and plain +, ? are literals.
  16 RE_BK_PLUS_QM = 4
  17
  18 # 1 means | binds tighter than ^ or $.
  19 # 0 means the contrary.
  20 RE_TIGHT_VBAR = 8
  21
  22 # 1 means treat \n as an _OR operator
  23 # 0 means treat it as a normal character
  24 RE_NEWLINE_OR = 16
  25
  26 # 0 means that a special characters (such as *, ^, and $) always have
  27 #   their special meaning regardless of the surrounding context.
  28 # 1 means that special characters may act as normal characters in some
  29 #   contexts.  Specifically, this applies to:
  30 #       ^ - only special at the beginning, or after ( or |
  31 #       $ - only special at the end, or before ) or |
  32 #       *, +, ? - only special when not after the beginning, (, or |
  33 RE_CONTEXT_INDEP_OPS = 32
  34
  35 # ANSI sequences (\n etc) and \xhh
  36 RE_ANSI_HEX = 64
  37
  38 # No GNU extensions
  39 RE_NO_GNU_EXTENSIONS = 128
  40
  41 # Now define combinations of bits for the standard possibilities.
  42 RE_SYNTAX_AWK = (RE_NO_BK_PARENS | RE_NO_BK_VBAR | RE_CONTEXT_INDEP_OPS)
  43 RE_SYNTAX_EGREP = (RE_SYNTAX_AWK | RE_NEWLINE_OR)
  44 RE_SYNTAX_GREP = (RE_BK_PLUS_QM | RE_NEWLINE_OR)
  45 RE_SYNTAX_EMACS = 0
  46
  47 # (Python's obsolete "regexp" module used a syntax similar to awk.)