package SPVM::Regex;

our $VERSION = "0.249";

1;

=encoding utf8

=head1 Name

SPVM::Regex - Regular Expressions

=head1 Description

Regex class in L<SPVM> has methods to perform pattern match and replacement using regular expressions.

L<Google RE2|https://github.com/google/re2> is used as the regular expression engine.

=head1 Usage

B<Re:>

  use Re;
  
  # Match
  my $string = "Hello World"
  my $match = Re->m($string, "^Hellow");
  
  # Replace
  my $string = "abc de abc";
  my $replace_info = Re->s(my $_ = [$string], ["abc", "g"], "ABC");
  $string = $_->[0];
  
  # Split
  my $parts = Re->split(" +", $string);

B<Regex:>

  use Regex;
  
  # Pattern match
  {
    my $re = Regex->new("ab*c");
    my $string = "zabcz";
    my $match = $re->match("zabcz");
  }
  
  # Pattern match - UTF-8
  {
    my $re = Regex->new("あ+");
    my $string = "いあああい";
    my $match = $re->match($string);
  }
  
  # Pattern match - Character class and the nagation
  {
    my $re = Regex->new("[A-Z]+[^A-Z]+");
    my $string = "ABCzab";
    my $match = $re->match($string);
  }
  
  # Pattern match with captures
  {
    my $re = Regex->new("^(\w+) (\w+) (\w+)$");
    my $string = "abc1 abc2 abc3";
    my $match = $re->match($string);
    
    if ($match) {
      my $cap1 = $match->cap1;
      my $cap2 = $match->cap2;
      my $cpa3 = $match->cap3;
    }
  }
  
  # Replace
  {
    my $re = Regex->new("abc");
    my $string = "ppzabcz";
    my $string_ref = [$string];
    
    # "ppzABCz"
    $re->replace($string_ref, "ABC");
  }
  
  # Replace with a callback and capture
  {
    my $re = Regex->new("a(bc)");
    my $string = "ppzabcz";
    my $string_ref = [$string];
    
    # "ppzABbcCz"
    $re->replace($string_ref, method : string ($re : Regex, $match : Regex::Match) {
      return "AB" . $match->cap1 . "C";
    });
  }
  
  # Replace global
  {
    my $re = Regex->new("abc");
    my $string = "ppzabczabcz";
    my $string_ref = [$string];
    
    # "ppzABCzABCz"
    $re->replace_g($string_ref, "ABC");
  }
  
  # Replace global with a callback and capture
  {
    my $re = Regex->new("a(bc)");
    my $string = "ppzabczabcz";
    my $string_ref = [$string];
    
    # "ppzABCbcPQRSzABCbcPQRSz"
    $re->replace_g($string_ref, method : string ($re : Regex, $match : Regex::Match) {
      return "ABC" . $match->cap1 . "PQRS";
    });
  }
  
  # . - single line mode
  {
    my $re = Regex->new("(.+)", "s");
    my $string = "abc\ndef";
    
    my $match = $re->match($string);
    
    unless ($match) {
      return 0;
    }
    
    unless ($match->cap1 eq "abc\ndef") {
      return 0;
    }
  }

=head1 Details

=head2 Regular Expression Syntax

See L<Google RE2 Syntax|https://github.com/google/re2/wiki/Syntax> about the syntax of regular expressions.

=head2 More Perlish Pattern Match and Replacement

Use L<Re|SPVM::Re> class if you want to use more Perlish pattern match and replacement.

=head1 Class Methods

=head2 new

C<static method new : L<Regex|SPVM::Regex> ($pattern : string, $flags : string = undef);>

Creates a new L<Regex|SPVM::Regex> object and compiles the regex pattern $pattern with the flags $flags, and retruns the new object.

Exceptions:

The regex pattern $pattern must be defined. Otherwise an exception is thrown.

If the regex pattern $pattern can't be compiled, an exception is thrown.

Examples:

  my $re = Regex->new("^ab+c");
  my $re = Regex->new("^ab+c", "s");

=head1 Instance Methods

=head2 match

C<method match : L<Regex::Match|SPVM::Regex::Match> ($string_value : string|L<StringBuffer|SPVM::StringBuffer>, $offset_ref : int* = undef, $length : int = -1);>

Performs a pattern match on the string or the StringBuffer object $string_value from the offset $$offset_ref to the length $length.

If the pattern match succeeds, return a new L<Regex::Match|SPVM::Regex::Match> object, otherwise returns undef.

$$offset_ref is updated to the next position if it is specified.

If $length is less than 0, it is set to the length of $string_value.

Exceptions:

$string_value must be defined. Otherwise an exception is thrown.

The type of $string_ref_value must be string or StringBuffer. Otherwise an exception is thrown.

$$offset_ref + $length must be less than or equal to the length of $string_value. Otherwise an exception is thrown.

=head2 replace

C<method replace : L<Regex::ReplaceInfo|SPVM::Regex::ReplaceInfo> ($string_ref_value : string[]|L<StringBuffer|SPVM::StringBuffer>, $replace : string|L<Regex::Replacer|SPVM::Regex::Replacer>, $offset_ref : int* = undef, $length : int = -1, $options : object[] = undef);>

The string to be replaced is either $string_ref_value->[0] when the type is string or $string_ref_value when the type is StringBuffer.

Replaces the string from the offset $$offset_ref to the length $length with the replacement string or the callback $replace with the options $options using a regular expression.

$$offset_ref is updated to the next position if it is specified.

If $length is less than 0, it is set to the length of $string_value.

If the replacement succeeds, returns a new L<Regex::ReplaceInfo|SPVM::Regex::ReplaceInfo>, otherwise retunrs undef.

Options:

=over 2

=item * C<global> : Int = 0

This option must be a L<Int|SPVM::Int> object. Otherwise an exception is thrown.

If the value of the L<Int|SPVM::Int> object is a true value, the global replacement is performed.

=back

Exceptions:

$string_ref_value must be defined. Otherwise an exception is thrown.

The type of $string_ref_value must be string or StringBuffer. Otherwise an exception is thrown.

$replace must be a string or a L<Regex::Replacer|SPVM::Regex::Replacer> object. Otherwise an exception is thrown.

$$offset_ref must be greater than or equal to 0. Otherwise an exception is thrown.

$$offset_ref + $length must be less than or equal to the length of $string_ref_value. Otherwise an exception is thrown.

Exceptions of the L<match_forward|/"match_forward"> method can be thrown.

=head2 replace_g

C<method replace_g  : L<Regex::ReplaceInfo|SPVM::Regex::ReplaceInfo> ($string_ref_value : string[]|L<StringBuffer|SPVM::StringBuffer>, $replace : string|L<Regex::Replacer|SPVM::Regex::Replacer>, $offset_ref : int* = undef, $length : int = -1, $options : object[] = undef):>

Calls L</replace> method given the same arguments but with C<global> option set to 1, and returns its return value.

=head2 split

C<method split : string[] ($string : string, $limit : int = 0);>

The same as L<Fn#split|SPVM::Fn/"split"> method, but the regular expression is used as the separator.

=head1 Repository

L<SPVM::Regex - Github|https://github.com/yuki-kimoto/SPVM-Regex>

=head1 See Also

=over 2

L<SPVM::Resource::RE2>

=back

=head1 Author

L<Yuki Kimoto|https://github.com/yuki-kimoto>

=head1 Contributors

=over 2

=item * L<Ryunosuke Murakami|https://github.com/ryun0suke22>

=item * L<greengorcer|https://github.com/greengorcer>

=back

=head1 Copyright & License

Copyright (c) 2023 Yuki Kimoto

MIT License
