loquat

Monadic parser combinators for JavScript, inspired by Parsec.

import * as lq from "@loquat/simple";

const nat = lq.digit.manyChars1().map(str => parseInt(str, 10));
const op = lq.choice([
  lq.char("+").return((a, b) => a + b),
  lq.char("-").return((a, b) => a - b),
]);
const expr =
  nat.bind(a =>
    op.bind(f =>
      nat.map(b =>
        f(a, b)
      )
    )
  );

const res = expr.parse("", "14+28"); // { success: true, value: 42 }

Packages

If you are not familiar with loquat, or you are using TypeScript, @loquat/simple is recommended.

• simple

For a more flexible and extensible framework, use @loquat/framework.

• framework

The core features and extensions are provided as separate packages.

• core
• prim
• char
• combinators
• monad
• expr
• qo
• token

For extension development, a chai plugin and some test helpers are available.

• testutil

License

Copyright 2019 Susisu

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.