type-factories

Lots of custom types for robustness and predictability

Content

• Another type factory?
• Available factories
  • makeValueType(BaseType, handler)
  • makeDataType(Types)
  • makeListType(Type, handler)
• License

Another type library?

There is so much boiler plate when handling data: Validating, converting, looping on attributes, plucking, dealing with undefined, and so on... This library provides predictable type factories. The capability of setting and getting data is removed from the user and instead data is always preprocessed on setting. Standard methods such as toString, valueOf, toPrecision, toExponential... are defined when needed so that console calls and implicit conversions work as expected (for the most part).

Available factories

makeValueType(BaseType, handler)

Types generated from this factory are scalar/1D in nature. They handle numbers and strings for the most part. The handler parameters allows to set conditions on teh contained data.

import {makeValueType} from 'type-factories';
 
const Integer = makeValueType(Number, {
  set (target, key, value) {
    if (key === 'value') {
      target.value = value === undefined ? 0 : Math.trunc(Number(value));
    } else {
      target[key] = value;
    }
    return true;
  }
});
 
Integer(2.4) === 2; // true
 
const i = new Integer('36.9');
i + i * 2.5 === 126;  // not 129.15

makeDataType(Types)

Types generated from this factory are a mixte bag of Value types. They are objects with strongly typed public properties.

import {makeDataType} from 'type-factories';
 
const Person = makeDataType({
  name: String,
  age: Number,
  female: Boolean
});
 
const person = new Person({
  name: 'John Doe',
  age: '55'
});
 
person.name === 'John Doe'; // true
person.age === 55; // true
person.female === false; // true
 
person.value = {
  name: 'John H. Doe',
  age: 56
};
 
person.name === 'John H. Doe'; // true
person.age === 56; // true
 
person.age = {
  name: 'Patrick Gray',
  age: '10',
};
person.name === 'John H. Doe'; // not 'Patrick Gray'
person.age === 10; // true

makeListType(Type, handler)

Types from this factory are vectorial/multiD in nature. They handle list of same Value type instances. The handler helps override some default behaviors

import {makeListType} from 'type-factories';
 
const Players = makeListType({
  number: Number,
  name: String
});
 
const players = new Players({
  number: 1,
  name: 'Kasparov'
},
{
  number: 2,
  name: 'Karpov'
});
 
players.push({
  number: '3',
  name: 'Fischer'
});
 
players.length === 3;
players[2].number === 3; // not '3'

License

type-factories is MIT licensed.

© 2017 Jason Lenoble