Regex Execution Flags — TS-Rex API Reference

Reference for TS-Rex flag methods: .global(), .ignoreCase(), .multiline(), .dotAll(), .withIndices(), .unicode(), .unicodeSets(), and .sticky().

Flags modify how the regex engine interprets and executes a pattern. In TS-Rex, flag methods alter the TypeScript return type of .exec() through the TFlags generic parameter.

Flag Summary

Method	Flag letter	TFlags key set	Return type effect
.global()	g	{ global: true }	exec() returns IterableIterator<SingleMatch>
.ignoreCase()	i	{ ignoreCase: true }	No change to return type
.multiline()	m	{ multiline: true }	No change to return type
.dotAll()	s	{ dotAll: true }	No change to return type
.withIndices()	d	{ hasIndices: true }	Adds indices property to SingleMatch
.unicode()	u	{ unicode: true }	No change to return type
.unicodeSets()	v	{ unicodeSets: true }	No change to return type
.sticky()	y	{ sticky: true }	No change to return type

.global()

Enables global matching. The g flag causes .exec() to find all non-overlapping matches. At the type level, MatchResult changes from SingleMatch | FailedMatch to IterableIterator<SingleMatch>.

import { rx } from "@fajarnugraha37/ts-rex";

const pattern = rx()
  .capture("num", rx().oneOrMore(rx().digit()))
  .global()
  .compile();

const results = pattern.exec("I have 3 apples and 42 bananas");

for (const result of results) {
  console.log(result.num); // "3", then "42"
}

.ignoreCase()

Enables case-insensitive matching.

const pattern = rx()
  .capture("greeting", rx().literal("hello"))
  .ignoreCase()
  .compile();

const result = pattern.exec("Hello, world!");
if (result.isMatch) {
  console.log(result.greeting); // "Hello"
}

.multiline()

Enables multiline mode. Changes the meaning of ^ and $ to match the start and end of each line.

.dotAll()

Enables dotAll mode. Causes .anyChar() (.) to match any character including newlines.

.withIndices()

Enables indices mode. Adds a readonly indices property to SingleMatch containing [start, end] tuples for the full match and every named capture group.

const pattern = rx()
  .capture("word", rx().oneOrMore(rx().wordChar()))
  .withIndices()
  .compile();

const result = pattern.exec("hello world");

if (result.isMatch) {
  console.log(result.indices.match); // [0, 5]
  console.log(result.indices.word); // [0, 5]
}

.unicode()

Enables Unicode mode. Required for .unicodeCodePoint() and .unicodeProperty().

.unicodeSets()

Enables Unicode sets mode (ES2024). The v flag is a superset of u, enabling set operations and string literals inside character classes.

.sticky()

Enables sticky mode. Causes the engine to match only at the exact position indicated by lastIndex.