---
name: "Lucy::Analysis::RegexTokenizer"
section: "3pm"
platform: "linux"
package: "liblucy-perl"
version: "0.3.3-7+b1"
release: "Debian 9 (Stretch)"
platforms: ["linux"]
url: "https://new.carta.tech/Lucy::Analysis::RegexTokenizer"
---

# Lucy::Analysis::RegexTokenizer(3pm)

Split a string into tokens.

## NAME

Lucy::Analysis::RegexTokenizer - Split a string into tokens.

## SYNOPSIS

```
    my $whitespace_tokenizer
        = Lucy::Analysis::RegexTokenizer->new( pattern => '\S+' );
    # or...
    my $word_char_tokenizer
        = Lucy::Analysis::RegexTokenizer->new( pattern => '\w+' );
    # or...
    my $apostrophising_tokenizer = Lucy::Analysis::RegexTokenizer->new;
    # Then... once you have a tokenizer, put it into a PolyAnalyzer:
    my $polyanalyzer = Lucy::Analysis::PolyAnalyzer->new(
        analyzers => [ $case_folder, $word_char_tokenizer, $stemmer ], );
```

## DESCRIPTION

Generically, "tokenizing" is a process of breaking up a string into an array of "tokens".  For instance, the string "three blind mice" might be tokenized into "three", "blind", "mice".

Lucy::Analysis::RegexTokenizer decides where it should break up the text based on a regular expression compiled from a supplied `"pattern"` matching one token.  If our source string is...

```
    "Eats, Shoots and Leaves."
```

... then a "whitespace tokenizer" with a `"pattern"` of `"\\S+"` produces...

```
    Eats,
    Shoots
    and
    Leaves.
```

... while a "word character tokenizer" with a `"pattern"` of `"\\w+"` produces...

```
    Eats
    Shoots
    and
    Leaves
```

... the difference being that the word character tokenizer skips over punctuation as well as whitespace when determining token boundaries.

## CONSTRUCTORS

### new( *\[labeled params\]* )

```
    my $word_char_tokenizer = Lucy::Analysis::RegexTokenizer->new(
        pattern => '\w+',    # required
    );
```

- •

  **pattern** - A string specifying a Perl-syntax regular expression which should match one token.  The default value is `"\w+(?:[\x{2019}']\w+)*"`, which matches "it's" as well as "it" and "O'Henry's" as well as "Henry".

## INHERITANCE

Lucy::Analysis::RegexTokenizer isa Lucy::Analysis::Analyzer isa Lucy::Object::Obj.