util.matches

Searches a string for N instances of a given regex.

Installation

This module uses yarn to manage dependencies and run scripts for development.

To install as an application dependency:

$ yarn add --dev util.matches

To build the app and run all tests:

$ yarn run all

Overview

The matches function will search through the given string for N occurrences of the given regex string. It will return an array of Match objects; one entry for each instance found. The Match structure contains the following values:

• groupIndex - When grouping symbols are used within a regex this structure will contain the index location within the matched string where that group starts. The index location is computed for each group.
• result - The return value from the Javascript regex exec().
• text - the string that was matched by the regex
• start - the absolute starting index from the front of the string being searched.
• end - the absolute ending index from the from front of the string being searched.

Usage

Simple match

import {Match, matches} from 'util.matches';

const data: string = 'a b c a b c a b c';
const res: Match[] = matches(data, /a/g);

// res[0].text = 'a'
// res[0].start = 0
// res[0].end = 0;

// res[1].text = 'a'
// res[1].start = 6
// res[1].end = 6

Match with grouping indicies

import {Match, matches} from 'util.matches';

const data: string = 'the date range is 01/02/2016 to 09/25/2017 blah';
const res: Match[] = matches(data, /(\d{2})\/(\d{2})\/(\d{4})/g);

// res[0].text = '01/02/2016');
// res[0].start = 18);
// res[0].end = 27);
// res[0].groupIndex[0] = 0); // 01
// res[0].groupIndex[1] = 3); // 02
// res[0].groupIndex[2] = 6); // 2016

// res[1].text = '09/25/2017');
// res[1].start = 32);
// res[1].end = 41);
// res[1].groupIndex[0] = 0); // 09
// res[1].groupIndex[1] = 3); // 25
// res[1].groupIndex[2] = 6); // 2017