mathjs/examples/advanced/custom_datatype.js at develop · lineCode/mathjs · GitHub

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// This example demonstrates importing a custom data type,

// and extending an existing function (add) with support for this data type.

const { create, factory, all } = require('../..')

const math = create(all)

// factory function which defines a new data type CustomValue

const createCustomValue = factory('CustomValue', ['typed'], ({ typed }) => {

// create a new data type

function CustomValue (value) {

this.value = value

}

CustomValue.prototype.isCustomValue = true

CustomValue.prototype.toString = function () {

return 'CustomValue:' + this.value

}

// define a new data type with typed-function

typed.addType({

name: 'CustomValue',

test: function (x) {

// test whether x is of type CustomValue

return x && x.isCustomValue === true

}

})

return CustomValue

})

// function add which can add the CustomValue data type

// When imported in math.js, the existing function `add` with support for

// CustomValue, because both implementations are typed-functions and do not

// have conflicting signatures.

const createAddCustomValue = factory('add', ['typed', 'CustomValue'], ({ typed, CustomValue }) => {

return typed('add', {

'CustomValue, CustomValue': function (a, b) {

return new CustomValue(a.value + b.value)

}

})

// import the new data type and function

math.import([

createCustomValue,

createAddCustomValue

])

// use the new type

const ans1 = math.add(new math.CustomValue(2), new math.CustomValue(3))

console.log(ans1.toString())

// outputs 'CustomValue:5'

// you can automatically use the new type in functions which use `add` under the hood:

const ans2 = math.sum(new math.CustomValue(6), new math.CustomValue(1), new math.CustomValue(2))

console.log(ans2.toString())

// outputs 'CustomValue:9'

mathjs/examples/advanced/custom_datatype.js at develop · lineCode/mathjs · GitHub

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