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

features

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

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

npm install vue-lazy-calc --save

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

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

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

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

(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

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

Thanks goes to these wonderful people (emoji key):

Vincent Guo 💻 📖 🚇

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