lRegExp

Transparently create linear-time (non-backtracking) regular expressions.

Usage

This library exports a drop-in replacement for the built-in RegExp.

npm install @ericcornelissen/lregexp

import RegExp from "@ericcornelissen/lregexp";
new RegExp("[linear]{6}");

Why

Backtracking regular expressions can take exponential time to evaluate, leading to the dreaded ReDoS vulnerability. Linear-time regular expressions avoid this by not backtracking.

Caveats

Not all regular expression constructs are valid in a linear-time regular expression and this library won't tell you your regular expression is incompatible unless you run it with the non-backtracking engine, in which case it throws an error.