NAME
String::Compile::Tr - compile tr/// expressions
VERSION
Version 0.03
SYNOPSIS
use String::Compile::Tr;
my $search = '/+=';
my $replace = '-_';
my $s = 'De/0xv5y3w8BpLF8ubOo+w==';
trgen($search, $replace, 'd')->($s);
# $s = 'De-0xv5y3w8BpLF8ubOo_w'DESCRIPTION
The usual approach when operands of a tr/// operator shall be variables is to apply eval on a string to interpolate the operands. The drawback of this approach are possible unwanted side effects induced by the variables' content, e.g.
$search = '//,warn-trapped,$@=~tr/';
eval "tr/$search//d";String::Compile::Tr offers an alternative where the content of a variable can be used as operand without eval'ing it.
trgen(*SEARCH*, *REPLACE*, *OPT*) compiles an anonymous sub that performs almost the same operation as tr/*SEARCH*/*REPLACE*/*OPT*, but allows variable operands.
trgen is imported by default by use String::Compile::Tr.
FUNCTIONS
trgen
trgen(search, replace, [options])trgen returns an anonymous subroutine that performs an almost identical operation as tr/search/replace/options. The tr target may be given as an argument to the generated sub or is the default input $_ otherwise.
ERRORS
trgen will throw an exception if an invalid option is specified.
When the tr operation cannot be compiled, trgen will return undef.
EXAMPLES
Proposed usages of this module are:
use String::Compile::Tr;
my $search = 'abc';
my $replace = '123';
my $tr = trgen($search, $replace);
my $s = 'fedcba';
$tr->($s);
# $s is 'fed321' now
my @list = qw(axy bxy cxy);
$tr->() for @list;
# @list is now ('1xy', '2xy', '3xy');
print trgen($search, $replace, 'r')->('fedcba'); # 'fed321'RESTRICTIONS
Character ranges are not supported in the search and replace lists. All characters are interpreted literally. This is caused by the fact that tr does not support these neither. It's the compiler that expands character ranges in tr's operands before handing them over.
AUTHOR
Jörg Sommrey, <git at sommrey.de>
LICENSE AND COPYRIGHT
This software is copyright (c) 2025 by Jörg Sommrey.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.
SEE ALSO
"tr/*SEARCHLIST*/*REPLACEMENTLIST*/cdsr" in perlop
Exporter::Tiny::Manual::Importing
Regexp::Tr provides a similar functionality, though this eval's its oprands.