in reply to Regex question is this one of those look (ahead|behind)s ?
In contrast to Re: Regex question is this one of those look (ahead|behind)s ?, produced using PPIx::Regexp::xplain because YAPE::Regex::Explain is dead; file ppixregexplain.pl needs _desc.pl, the explanation
| # my $regstr = join '', ; # The regular expression (PPI::Token::Regexp::Substitute): ; # # s/^(?<!abc)def/$1xyz/ # # matches as follows: #r: PPIx::Regexp / PPI::Token::Regexp::Substitute #r= "s/^(?<!abc)def/\$1xyz/" # |
"s", |
# address=/1/C0 ; xRe::Token::Structure ; Represent structural elements. #"s", # ------------------------------------------------------------------ |
| # address=/1/C1 ; xRe::Structure::Regexp ; Represent the top-level regular expression # ------ |
"/", |
# address=/1/C1/S0 ; xRe::Token::Delimiter ; Represent the delimiters of the regular expression #"/", # ------------------------------------------------------------------ |
"^", |
# # address=/1/C1/C0 ; xRe::Token::Assertion ; simple zero-width assertion (zero-length, between pos()itions) # match the beginning of the string #"^", # ------------------------------------------------------------------ |
| # # address=/1/C1/C1 ; xRe::Structure::Assertion ; a parenthesized assertion # (the grouptype below explains which one) # ------------ |
"(", |
# address=/1/C1/C1/S0 ; xRe::Token::Structure ; Represent structural elements. #"(", # ------------------------------------------------------------------ |
"?<!", |
# # address=/1/C1/C1/T0 ; xRe::Token::GroupType::Assertion ; a look ahead or look behind assertion # (?<!pattern) # L<perlre/(?<!pattern)> # A zero-width negative look-behind assertion. # For example C</(?<!bar)foo/> matches any occurrence of "foo" that does not follow "bar". # Works only for fixed-width look-behind. #"?<!", # ------------------------------------------------------------------ |
"a", |
# # address=/1/C1/C1/C0 ; xRe::Token::Literal ; a literal character # ordinal= ord( chr( 97 ) ) alias \N{U+0061} alias \141 alias LATIN SMALL LETTER A alias a #"a", # ------------------------------------------------------------------ |
"b", |
# # address=/1/C1/C1/C1 ; xRe::Token::Literal ; a literal character # ordinal= ord( chr( 98 ) ) alias \N{U+0062} alias \142 alias LATIN SMALL LETTER B alias b #"b", # ------------------------------------------------------------------ |
"c", |
# # address=/1/C1/C1/C2 ; xRe::Token::Literal ; a literal character # ordinal= ord( chr( 99 ) ) alias \N{U+0063} alias \143 alias LATIN SMALL LETTER C alias c #"c", # ------------------------------------------------------------------ |
")", |
# address=/1/C1/C1/F0 ; xRe::Token::Structure ; Represent structural elements. #")", # ------------------------------------------------------------------ |
"d", |
# # address=/1/C1/C2 ; xRe::Token::Literal ; a literal character # ordinal= ord( chr( 100 ) ) alias \N{U+0064} alias \144 alias LATIN SMALL LETTER D alias d #"d", # ------------------------------------------------------------------ |
"e", |
# # address=/1/C1/C3 ; xRe::Token::Literal ; a literal character # ordinal= ord( chr( 101 ) ) alias \N{U+0065} alias \145 alias LATIN SMALL LETTER E alias e #"e", # ------------------------------------------------------------------ |
"f", |
# # address=/1/C1/C4 ; xRe::Token::Literal ; a literal character # ordinal= ord( chr( 102 ) ) alias \N{U+0066} alias \146 alias LATIN SMALL LETTER F alias f #"f", # ------------------------------------------------------------------ |
"/", |
# address=/1/C1/F0 ; xRe::Token::Delimiter ; Represent the delimiters of the regular expression #"/", # ------------------------------------------------------------------ |
| # address=/1/C2 ; xRe::Structure::Replacement ; Represent the replacement in s/// # ------ |
"\$1", |
# # address=/1/C2/C0 ; xRe::Token::Interpolation ; Represent an interpolation in the PPIx::Regexp package. # It is a variable! subject to \F\l\u\L\U\Q\E # L<perlre/\F\l\u\L\U\Q\E> # It is a variable! whose contents are used as a REPLACEMENT string (unless it starts with \ in which case its not a variable anymore) #"\$1", # ------------------------------------------------------------------ |
"x", |
# # address=/1/C2/C1 ; xRe::Token::Literal ; a literal character # ordinal= ord( chr( 120 ) ) alias \N{U+0078} alias \170 alias LATIN SMALL LETTER X alias x #"x", # ------------------------------------------------------------------ |
"y", |
# # address=/1/C2/C2 ; xRe::Token::Literal ; a literal character # ordinal= ord( chr( 121 ) ) alias \N{U+0079} alias \171 alias LATIN SMALL LETTER Y alias y #"y", # ------------------------------------------------------------------ |
"z", |
# # address=/1/C2/C3 ; xRe::Token::Literal ; a literal character # ordinal= ord( chr( 122 ) ) alias \N{U+007A} alias \172 alias LATIN SMALL LETTER Z alias z #"z", # ------------------------------------------------------------------ |
"/", |
# address=/1/C2/F0 ; xRe::Token::Delimiter ; Represent the delimiters of the regular expression #"/", # ------------------------------------------------------------------ |
"", |
# address=/1/C3 ; xRe::Token::Modifier ; Represent 1)embedded pattern-match modifiers or 2)(trailing) modifiers for operators match, substitution, regexp constructor #"", # ------------------------------------------------------------------ |
| ;;;;;;;;;;
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Also interesting (but tad more pita to install) is wxPPIxregexplain.pl
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