Toky NPM | npm.io

Toky

Toky is a configurable general-purpose code tokenizer that supports comment and string skipping. When you need to find specific structure in a code block such as imports in JavaScript, or URLs in CSS, and you don't want to use a full-blown Parser you can create a specific tokenizer to do the job.

API

The core API is just one function.

type Descriptors =
  | "string"
  | "text"
  | "line-comment"
  | "multi-comment"
  | "unclosed-string"
  | "unclosed-comment"
  | "space";

interface Token<Types = Descriptors> {
  type: Types;
  start: number;
  end: number;
  value: string;
}

interface Options<T extends Token<unknown>> {
  shouldAddToken(type: T["type"], value: string): boolean;
  isStringDelimiter(char: string): boolean;
  isDelimiter(char: string): boolean;
  isWhitespace(char: string): boolean;
  createToken(value: string, type: T["type"], start: number, end: number): T;
}

function tokenize<T extends Token<unknown>>(
  source: string,
  {
    isDelimiter,
    isStringDelimiter,
    isWhitespace,
    shouldAddToken,
    createToken,
  }: Options<T>
): T[];

You can extend the tokenizer by providing options that match your use-case and extending the Token type.

type Delimiters = "(" | ")" | "," | ";" | ":";
type CSSCodeToken = Token<Descriptors | Delimiters>;
tokenize<CSSCodeToken>(source, {...})

How it works

The main idea is looping over all the characters and splitting tokens via isDelimiter, isWhitespace, and isStringDelimiter. After that, you can decide about the shape of the token with createToken and if it should be included with shouldAddToken