decorator-eq

Decorator for portation of haskell typeclass EQ

The Eq Interface defines equality and inequality in typescript. The decorator implements the EQ-Interface. On the other hand it is a library for funtions. Mainly Lists of this interface are used.

There is an es5-translation in the dist-directory. tsc was used for transpiling.

Installation

npm install decorator-eq --save

Usage

Decorator

  const carConfig = new EqConfig();
  
  @Eq.implement({
      config: carConfig
  })
  class Car implements IEq {
    @Eq.field({})
    private interior:TInterior;
 
    @Eq.field({fuzzy:true})
    private name:string;
    
    constructor(interior:TInterior, name:string){
        this.interior=interior;
        this.name=name;
    }
    
    //this is neccessary to ensure the interface
    eq:(a:IEq)=>boolean;
    neq:(a:IEq)=>boolean;
 }

Notice the Configuration-Object. Objects of car can now be seen as equal, if the two properties interior and name are the same. Be aware that the properties can be any type that support "===" or has IEq implemented.

Using the EQ-Library

eq(cs:IEq[], ref:IEq, config:IEqConfig):IEq[]

  eq(listOfCars, new Car('plastic','cheapo'), config:IEqConfig):IEq[]
  eq(listOfCars, new Car(null,'bmw'), config:IEqConfig):IEq[] // reveals all bmws

fuzzyEq(cs:IEq[], ref:IEq, config:IEqConfig):IEq[]

  fuzzyEq(listOfCars, new Car(null,'di'), config:IEqConfig):IEq[] //reveals Audi and Cadillac 

neq(cs:IEq[], ref:IEq, config:IEqConfig):IEq[]

  neq(listOfCars, new Car('leather',null), config:IEqConfig):IEq[] //reveals all none leather cars 

Using EqConfig

clone():IEqConfig

  let copyOfConfig = config.clone(); 

fields:Array

  let newFields:Array<IField> = [];
  copyOfFields.fields.foreach((val, key) => if(key%2) newFields.push(val));
  copyOfFields.fields = newFields;

Using EqOr

fuzzyEq(cs:IEq[], refs:IEq[], config:IEqConfig):IEq[]

  fuzzyEq(listOfCars, new Car('leather', null)) //all listOfCars
  fuzzyEq(listOfCars, new Car('leather', 'di')) //reveals Audi and Cadillac or leather cars

eq(cs:IEq[], refs:IEq[], config:IEqConfig):IEq[]

  eq(listOfCars, new Car('leather', null)) //all leather cars
  eq(listOfCars, new Car('leather', 'di')) //reveals leather cars
  eq(listOfCars, new Car('leather', 'audi')) //reveals leather cars or audis

Tests

npm test

Contributing

In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint and test your code.

Release History

• 0.1.0 Initial release
• 0.1.2 transpiling from typescript to es5
• 0.1.3 reorder code in multiple files
• 0.1.4 better transpiling
• 0.1.5 fuzzy field cloning
• 0.1.6 config-fields handling