dreambo8563/vue-lazy-calc

simple calculation lib with lazy feature 🎲➕➖➗✖️

vue-lazy-calc

this is a simple calculation plugin in lazy way. (inspired by lodash)

features

• vue friendly
• strong typed
• lazy evaluation
• chaining methods
• code coverage 100%

TODO:

• seperate simple lazy class from base class
• support more operator in stream api

Install

npm install vue-lazy-calc --save

Quick Start

import lzCalc from "vue-lazy-calc"
Vue.use(lzCalc)

Methods

• this.$lzCalc in Component context.
• Vue.$lzCalc in global.

API list

base

export declare class LazyBase {
  lazy(init?: number): LazyCalc
  stream(s?: LazyCalc): LazyStream
}

• lazy => init a new instance with optional initValue
• stream => init a stream to operate between multiple lazy instance with optional init instantce

simple

export declare class LazyCalc {
  add(y: number): LazyCalc
  divide(y: number): LazyCalc
  subtract(y: number): LazyCalc
  multiply(y: number): LazyCalc
  do(fn: operatorFunc): LazyCalc
  ceil(precision?: number): LazyCalc
  floor(precision?: number): LazyCalc
  round(precision?: number): LazyCalc
  default(fallback: any): LazyCalc
  value(): any
}

• add/subtract/divide/multiple => + - * / (simple calculation) between numbers
• round/floor/ceil => deal with precision of the float number
• value => excute the declared method chain
• default => set default value if previous operations get NaN
• do => accept a custormized function for the number

Examples

(1+3)*2/3 with precision 2

const result = this.$lzCalc
  .lazy(1)
  .add(3)
  .multiply(2)
  .divide(3)
  .round(2)

console.log(result.value()) // 2.67

const addThree = result.add(3)
console.log(addThree.value()) // 2.67+ 3 =>5.67

Stream

declare class LazyStream {
  add(y: LazyCalc): LazyStream
  subtract(y: LazyCalc): LazyStream
  multiply(y: LazyCalc): LazyStream
  divide(y: LazyCalc): LazyStream
  round(precision?: number): LazyStream
  ceil(precision?: number): LazyStream
  floor(precision?: number): LazyStream
  do(fn: operatorFunc): LazyStream
  default(fallback: any): LazyStream
  value(): any
}

const result = this.$lzCalc
  .lazy(1)
  .add(3)
  .multiply(2)
  .divide(3)
  .round(2)

const tmp = this.$lzCalc.lazy(2).add(3)
const s = this.$lzCalc.stream(result).add(tmp)

console.log(s.value()) // 2.67 + 5 => 7.67

1. when declare the result variable, no calculation excuted until value()
2. you can reuse the declare variable

License

Contributors

Thanks goes to these wonderful people (emoji key):

Vincent Guo 💻 📖 🚇

This project follows the all-contributors specification. Contributions of any kind welcome!

vue-lazy-calc's Issues

edge case: receive object and do later incorrect

    const r22 = this.$lzCalc.lazy({ a: 3 }).do(x => x.a).add(4)
    console.log( r22.value());

got undefined

An in-range update of eslint-plugin-vue is breaking the build 🚨

The devDependency eslint-plugin-vue was updated from 5.2.2 to 5.2.3.

🚨 View failing branch.

This version is covered by your current version range and after updating it in your project the build failed.

eslint-plugin-vue is a devDependency of this project. It might not break your production code or affect downstream projects, but probably breaks your build or test tools, which may prevent deploying or publishing.

Status Details

• ❌ Travis CI - Branch: The build errored.

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Commits

The new version differs by 3 commits.

• 1064f10 🔖 5.2.3
• 158c10b chore: update ESLint to v6
• 082c03d fix: remove eslint internal traverser (#910)

See the full diff

FAQ and help

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