Pattern Tokenizeredit

A tokenizer of type pattern that can flexibly separate text into terms via a regular expression. Accepts the following settings:

Setting Description


The regular expression pattern, defaults to \W+.


The regular expression flags.


Which group to extract into tokens. Defaults to -1 (split).

IMPORTANT: The regular expression should match the token separators, not the tokens themselves.

group set to -1 (the default) is equivalent to "split". Using group >= 0 selects the matching group as the token. For example, if you have:

pattern = '([^']+)'
group   = 0
input   = aaa 'bbb' 'ccc'

the output will be two tokens: 'bbb' and 'ccc' (including the ' marks). With the same input but using group=1, the output would be: bbb and ccc (no ' marks).