@kikuchan/string-reader

Lightweight sequential string reader with simple matching helpers.

Install

npm install -D @kikuchan/string-reader

Quick Start

import { StringReader } from '@kikuchan/string-reader';

const r = new StringReader('key=value;rest');
r.read(3);                // 'key'
r.match('=');             // advances
const val = r.readUntil(';'); // 'value'

r.rewind();
r.startsWith('key');      // ['key'] (does not advance)

API

• Position/state:

  • position, size, remain, eof()
  • seek(n), skip(n?) (both clamp to range 0..size)

• Matching:

  • startsWith(string | RegExp) -> string[] | null (anchored at current position; does not advance)
  • match(string | RegExp, translate?) -> T | string[] | null (advances on match)
  • search(string | RegExp, translate?) -> { skipped, matched } | T | null (advances to end of match when found)
  • skipUntil(string | RegExp) -> boolean (advances to start of match when found)
  • readUntil(string | RegExp) -> string | null (reads up to but not including match; does not consume match)

• Reading:

  • read(n?: number) -> string
    • Defaults to 1 char; requires n > 0 (throws RangeError otherwise).
    • Clamps at end-of-string; returns empty string at EOF.

Notes

• RegExp behavior: startsWith is anchored (sticky-like), while search/readUntil scan forward.