Table of Contents
NAME
Gzz::Text::Utils
AUTHOR
Francis Grizzly Smit (grizzly@smit.id.au)
VERSION
v0.1.5
TITLE
RegexUtils
SUBTITLE
A Raku class/module that provides helpers for Regex stuff both Perl5 and EMCA262Regex
COPYRIGHT
LGPL V3.0+ LICENSE
Introduction
A Raku class/module that provides helpers for Regex stuff both Perl5 and EMCA262Regex.
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Motivations
I have a program which exists as a Mod_Perl web program,and a Raku command line version. The Mod_Perl version also uses JavaScript and <JavaScript/EMCA> regexes I found that there was an all most perfect solution for the use of these regexes in the EMCA262Regex module, but I still needed to convert the strings to regexes as I wanted to add options, RegexUtils::CreateEMCA262Regex is my solution to this problem I then added RegexUtils::CreatePerlRegex for doing the same for Perl5 regexes.
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Grammars
grammar FlagsPerl5Modern & action class FlagsPerl5ModernActions
Support for using a limited range of flags for use with Perl 5 style regexes, using Raku's style of regex flags.
grammar FlagsPerl5Modern {
token TOP { <flags> }
token flags { <flag>+ % ':' }
token flag { \w+ }
}
class FlagsPerl5ModernActions {
method TOP($/) { make $<flags>.made }
method flag($/) {
given ~$/ {
when 'i' {
make ':ignorecase';
}
when 'ignorecase' {
make ':ignorecase';
}
when 'm' { make ':ignoremark'; }
when 'ignoremark' { make ':ignoremark'; }
when 's' { make ':sigspace'; }
when 'sigspace' { make ':sigspace'; }
default: { make ''; }
}
}
method flags($/) {
my $made-elts = $<flag>».made.join('');
make $made-elts;
}
}
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grammar FlagsEMCA262Modern & action class FlagsEMCA262ModernActions
A grammar and action pair to parse modern style Raku flags and get rid of ones that do not fit with ECMA regexes.
grammar FlagsEMCA262Modern {
token TOP { <flags> }
token flags { <flag>+ % ':' }
token flag { \w+ }
}
class FlagsEMCA262ModernActions {
method TOP($/) { make $<flags>.made }
method flag($/) {
given ~$/ {
when 'i' {
make ':ignorecase';
}
when 'ignorecase' {
make ':ignorecase';
}
when 'g' { make ':global'; }
when 'global' { make ':global'; }
default: { make ''; }
}
}
method flags($/) {
my $made-elts = $<flag>».made.join('');
make $made-elts;
}
}
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grammar FlagsPerl5Old & action class FlagsPerl5OldActions
A grammar and action pair to parse old style Perl flags into modern Raku flags.
grammar FlagsPerl5Old {
token TOP { <flags> }
token flags { <flag>+ % <ww> }
token flag { \w }
}
class FlagsPerl5OldActions {
method TOP($/) { make $<flags>.made }
method flag($/) {
given ~$/ {
when 'i' { make ':ignorecase'; }
when 'm' { make ':ignoremark'; }
when 'g' { make ':global'; }
when 'x' { make ':sigspace'; }
default: { make ''; }
}
}
method flags($/) {
my $made-elts = $/<flag>».made.join('');
make $made-elts;
}
}
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grammar FlagsEMCA262Old & action class FlagsEMCA262OldActions
A grammar and action pair to convert ECMA262Regex flags into Raku ones
grammar FlagsEMCA262Old {
token TOP { <flags> }
token flags { <flag>+ % <ww> }
token flag { \w }
}
class FlagsEMCA262OldActions {
method TOP($/) { make $<flags>.made }
method flag($/) {
given ~$/ {
when 'i' { make ':ignorecase'; }
when 'g' { make ':global'; }
default: { make ''; }
}
}
method flags($/) {
my $made-elts = $/<flag>».made.join('');
make $made-elts;
}
}
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Methods
CreatePerlRegex(…)
Creates a Perl5 regex from a string with some options suported.
Note: not all raku flags are supported due to diffrences between the flags in the two languages.
Here is some exaple use.
[0] > use RegexUtils;
Nil
[1] > my $regex-perl5 = RegexUtils.CreatePerlRegex('^fo+\n$', ':ignorecase');
rx:Perl5:ignorecase/^fo+\n$/
[2] > so 'Fooo' ~~ $regex-perl5;
False
[3] > so "Fooo\n" ~~ $regex-perl5;
True
[4] > say $regex-perl5;
rx:Perl5:ignorecase/^fo+\n$/
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CreateEMCA262Regex(…)
Creates a regex from a string containing a EMCA262Regex with some options suported.
CreateEMCA262Regex converts a EMCA262 Regex to a raku one. using the EMCA262Regex package and applies flags to it.
Here is some exaple use.
[0] > use RegexUtils;
Nil
[1] > my $regex-emca = RegexUtils.CreateEMCA262Regex('^[f][o]+\n', ':ignorecase');
rx:ignorecase/^<[f]><[o]>+\n/
[2] > so "Fooo\n" ~~ $regex-emca;
True
[3] > so " Fooo\n" ~~ $regex-emca;
False
Note: ignorecase only works for cases like below due to how EMCA262Regex translates the charater constants, this is a problem that needs solving.
e.g.
[0] > use RegexUtils;
Nil
[1] > my $regex-emca = RegexUtils.CreateEMCA262Regex('^fo+\n', ':ignorecase');
rx:ignorecase/^\x66\x6F+\n/
[2] > so "Fooo\n" ~~ $regex-emca;
False
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get-modern-perl5-flags(…)
A method to apply the RegexUtils::FlagsPerl5Modern grammar to a string, in order to filter flags.
method get-modern-perl5-flags(Str:D $flags --> Str:D) {
my $actions = RegexUtils::FlagsPerl5ModernActions;
my $match = RegexUtils::FlagsPerl5Modern.parse($flags.substr(1), :$actions);
without $match {
die "invalid flags";
}
return $match.made;
} # method get-modern-perl5-flags(Str:D $flags --> Str:D) #
get-old-perl5-flags(…)
Translate old style Perl flags into Raku ones using the grammar action pair
method get-old-perl5-flags(Str:D $flags --> Str:D) {
my $actions = RegexUtils::FlagsPerl5OldActions;
my $match = RegexUtils::FlagsPerl5Old.parse($flags, :$actions);
without $match {
die "invalid flags $flags";
}
return $match.made;
} # method get-old-perl5-flags(Str:D $flags --> Str:D) #
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get-modern-emca262-flags(…)
Filter modern flags for use with EMCA262Regex's.
method get-modern-emca262-flags(Str:D $flags --> Str:D) {
my $actions = RegexUtils::FlagsEMCA262ModernActions;
my $match = RegexUtils::FlagsEMCA262Modern.parse($flags.substr(1), :$actions);
without $match {
die "invalid flags";
}
return $match.made;
} # method get-modern-emca262-flags(Str:D $flags --> Str:D) #
get-old-emca262-flags(…)
Translate old style EMCA262Regex flags into Raku ones.
method get-old-emca262-flags(Str:D $flags --> Str:D) {
my $actions = RegexUtils::FlagsEMCA262OldActions;
my $match = RegexUtils::FlagsEMCA262Old.parse($flags, :$actions);
without $match {
die "invalid flags $flags";
}
return $match.made;
} # method get-old-emca262-flags(Str:D $flags --> Str:D) #
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