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✨ feat: implement '@algorithm.ts/calculate'
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Diff for: ‎README.md

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A monorepo contains some of common algorithms and data structures written in
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Typescript.
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Typescript. (no third-party dependencies)
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## Overview
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Package | Description
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:----------------------------------:|:--------------------------
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[@algorithm.ts/binary-index-tree][] | Binary Index Tree.
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[@algorithm.ts/calculate][] | A tiny calculator for integer arithmetics.
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[@algorithm.ts/circular-queue][] | Circular queue.
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[@algorithm.ts/dijkstra][] | Dijkstra algorithm optimized with [@algorithm.ts/priority-queue][]. #ShortestPath.
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[@algorithm.ts/dinic][] | Dinic algorithm. #MaxFlow, #NetworkFlow.
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[homepage]: https://github.com/guanghechen/algorithm.ts
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[@algorithm.ts/binary-index-tree]: ./packages/binary-index-tree
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[@algorithm.ts/calculate]: ./packages/calculate
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[@algorithm.ts/circular-queue]: ./packages/circular-queue
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[@algorithm.ts/dijkstra]: ./packages/dijkstra
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[@algorithm.ts/dinic]: ./packages/dinic

Diff for: ‎packages/calculate/README.md

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<header>
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<h1 align="center">
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<a href="https://github.com/guanghechen/algorithm.ts/tree/main/packages/calculate#readme">@algorithm.ts/calculate</a>
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</h1>
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<div align="center">
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<a href="https://www.npmjs.com/package/@algorithm.ts/calculate">
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<img
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alt="Npm Version"
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src="https://img.shields.io/npm/v/@algorithm.ts/calculate.svg"
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/>
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</a>
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<a href="https://www.npmjs.com/package/@algorithm.ts/calculate">
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<img
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alt="Npm Download"
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src="https://img.shields.io/npm/dm/@algorithm.ts/calculate.svg"
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/>
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</a>
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<a href="https://www.npmjs.com/package/@algorithm.ts/calculate">
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<img
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alt="Npm License"
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src="https://img.shields.io/npm/l/@algorithm.ts/calculate.svg"
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/>
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</a>
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<a href="#install">
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<img
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alt="Module Formats: cjs, esm"
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src="https://img.shields.io/badge/module_formats-cjs%2C%20esm-green.svg"
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/>
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</a>
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<a href="https://github.com/nodejs/node">
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<img
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alt="Node.js Version"
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src="https://img.shields.io/node/v/@algorithm.ts/calculate"
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/>
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</a>
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<a href="https://github.com/facebook/jest">
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<img
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alt="Tested with Jest"
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src="https://img.shields.io/badge/tested_with-jest-9c465e.svg"
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/>
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</a>
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<a href="https://github.com/prettier/prettier">
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<img
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alt="Code Style: prettier"
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src="https://img.shields.io/badge/code_style-prettier-ff69b4.svg?style=flat-square"
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/>
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</a>
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</div>
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</header>
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<br/>
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A tiny calculator for integer arithmetics such as `+-*/()`.
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## Install
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* npm
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```bash
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npm install --save @algorithm.ts/calculate
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```
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* yarn
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```bash
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yarn add @algorithm.ts/calculate
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```
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* deno
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```typescript
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import { createDLX } from 'https://raw.githubusercontent.com/guanghechen/algorithm.ts/main/packages/calculate/src/index.ts'
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```
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## Usage
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* Basic
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```typescript
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import calculate from '@algorithm.ts/calculate'
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calculate('-2+1') // => -1
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calculate('-2*3 + 2*5*3/6') // => -1
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calculate('(1+(4+5+2)-3)+(6+8)') // => 23
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```
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* Illegal inputs
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```typescript
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import calculate from '@algorithm.ts/calculate'
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calculate('-2++1') // => NaN
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calculate('-2*/23') // => NaN
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calculate('1+(4+5+2))') // => NaN
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calculate('1+(4+5+2') // => NaN
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```
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* A solution of https://leetcode.com/problems/basic-calculator/
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```typescript
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export { calculate } from '@algorithm.ts/calculate'
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```
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## Related
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* [编译原理-语法制导翻译实现计算器][calculate]
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[homepage]: https://github.com/guanghechen/algorithm.ts/tree/main/packages/calculate#readme
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[calculate]: https://me.guanghechen.com/post/fundamentals-of-compiling/exercise/

Diff for: ‎packages/calculate/__test__/calculate.spec.ts

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import calculate from '../src'
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describe('calculate', function () {
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const data = [
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{
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input: '-2+1',
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answer: -1,
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},
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{
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input: '2 + 2 * 3',
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answer: 8,
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},
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{
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input: '(2 + 2) * 3',
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answer: 12,
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},
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{
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input: '2 * 2 + 3',
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answer: 7,
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},
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{
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input: '(1+(4+5+2)-3)+(6+8)',
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answer: 23,
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},
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{
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input: '-2*3 + 2*5*3/6',
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answer: -1,
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},
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{
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input: '+2-3',
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answer: -1,
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},
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{
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input: '-2*/2',
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answer: Number.NaN,
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},
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{
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input: '1+(4+5+2))',
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answer: Number.NaN,
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},
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{
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input: '1+(4+5+2',
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answer: Number.NaN,
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},
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{
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input: '-2++1',
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answer: Number.NaN,
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},
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]
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for (const kase of data) {
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// eslint-disable-next-line jest/valid-title
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test(kase.input, function () {
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expect(calculate(kase.input)).toEqual(kase.answer)
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})
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}
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})

Diff for: ‎packages/calculate/package.json

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{
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"name": "@algorithm.ts/calculate",
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"version": "1.0.16",
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"description": "A tiny calculator for integer arithmetics such as '+-*/()'",
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"author": {
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"name": "guanghechen",
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"url": "https://github.com/guanghechen/"
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},
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"repository": {
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"type": "git",
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"url": "https://github.com/guanghechen/algorithm.ts.git",
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"directory": "packages/calculate"
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},
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"homepage": "https://github.com/guanghechen/algorithm.ts/tree/main/packages/calculate#readme",
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"keywords": [
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"calculate",
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"calculator",
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"integer arithmetic"
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],
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"main": "lib/cjs/index.js",
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"module": "lib/esm/index.js",
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"types": "lib/types/index.d.ts",
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"source": "src/index.ts",
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"license": "MIT",
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"engines": {
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"node": ">= 14.15.0"
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},
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"files": [
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"lib/",
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"!lib/**/*.js.map",
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"!lib/**/*.d.ts.map",
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"package.json",
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"CHANGELOG.md",
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"LICENSE",
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"README.md"
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],
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"scripts": {
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"build": "cross-env NODE_ENV=production rollup -c ../../rollup.config.js",
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"prebuild": "rimraf lib/ && tsc -p tsconfig.src.json --emitDeclarationOnly",
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"prepublishOnly": "cross-env ROLLUP_SHOULD_SOURCEMAP=false yarn build",
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"test": "cross-env TS_NODE_FILES=true jest --config ../../jest.config.js --rootDir ."
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}
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}

Diff for: ‎packages/calculate/src/calculate.ts

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import { TokenSymbol, idx, ll1Table, sddTable } from './constant'
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export function parseInteger(s: string, start: number): [number, number] {
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let result = 0
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let i: number = start
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for (; i < s.length; ++i) {
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const c = s[i]
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if (!/\d/.test(c)) break
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result = result * 10 + Number(c)
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}
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return [i, result]
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}
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export function calculate(
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rawExpression: string,
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parseNumber: (
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s: string,
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start: number,
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) => [nextIndex: number, value: number] = parseInteger,
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): number {
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const expression = rawExpression.replace(/[\s]+/g, '')
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let cur = 0
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const result: number = dfs(idx('A'), 0, 0)
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return cur === expression.length ? result : Number.NaN
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function dfs(id: number, syn: number, inh: number): number {
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if (cur === expression.length) {
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// Only D and E could be parsed as \varepsilon
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if (id === TokenSymbol.D || id === TokenSymbol.E) return inh
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return Number.NaN
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}
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const id0 = idx(expression[cur])
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// Unrecognized symbol.
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if (id0 === undefined) return Number.NaN
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// Matched an operator.
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if (id === id0) {
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// Matched digits.
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if (id0 === TokenSymbol.DIGIT) {
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const [nextCur, value] = parseNumber(expression, cur)
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// No valid digit found.
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if (cur === nextCur) return Number.NaN
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cur = nextCur
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return value
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}
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cur += 1
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return syn
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}
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// Syntax error.
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if (id > 0) return Number.NaN
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const ssdId = ll1Table[-id][id0]
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if (ssdId < 0) return Number.NaN
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const tokens: ReadonlyArray<number> = sddTable[ssdId]
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const syn0: number = tokens.length > 0 ? dfs(tokens[0], 0, 0) : 0
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if (Number.isNaN(syn0)) return Number.NaN
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switch (ssdId) {
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// 0: A --> BD
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case 0:
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return dfs(tokens[1], 0, syn0)
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// 1: A --> +BD
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case 1: {
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const val1: number = dfs(tokens[1], 0, 0)
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return dfs(tokens[2], 0, val1)
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}
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// 2: A --> -BD
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case 2: {
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const val1: number = dfs(tokens[1], 0, 0)
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return dfs(tokens[2], 0, -val1)
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}
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// 3: B --> CE
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case 3:
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return dfs(tokens[1], 0, syn0)
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// 4: C --> digit
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case 4:
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return syn0
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// 5: C --> (A)
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case 5: {
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const result: number = dfs(tokens[1], 0, 0)
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const result2: number = dfs(tokens[2], 0, 0)
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return Number.isNaN(result2) ? Number.NaN : result
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}
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// 6: D --> +BD
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case 6: {
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const val1: number = dfs(tokens[1], 0, 0)
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return dfs(tokens[2], 0, inh + val1)
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}
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// 7: D --> -BD
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case 7: {
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const val1: number = dfs(tokens[1], 0, 0)
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return dfs(tokens[2], 0, inh - val1)
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}
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// 8: D --> \varepsilon
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case 8:
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return inh
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// 9: E --> *CE
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case 9: {
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const val1: number = dfs(tokens[1], 0, 0)
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return dfs(tokens[2], 0, inh * val1)
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}
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// 10: E --> /CE
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case 10: {
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const val1: number = dfs(tokens[1], 0, 0)
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return dfs(tokens[2], 0, inh / val1)
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}
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// 11: E --> \varepsilon
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case 11:
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return inh
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// Here is not reachable.
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default:
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return Number.NaN
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}
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}
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}

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