lazyrange

Example

import range from 'lazyrange';

// for-of loops
for (let i of range(5)) {
    // 0, 1, 2, 3, 4
}

// array-like iteration
range(5, 10).each(function(i) {
    // 5, 6, 7, 8, 9
});

API

Creation

import range from 'lazyrange';

let foo = range(0, 5);
let bar = new range.Range(5, 0, -1);

new Range(end) -> Range

Creates a range starting at 0 and ending at end using a step of 1.

new Range(start, end, [step]) -> Range

Creates a range from start to end using a step that defaults to 1,

range( ... ) -> Range

Shortcut method to return a new instance of a range.

Methods

Range.prototype.toArray() -> Array

Evaluates the range into an array.

let arr = range(5).toArray();
// [0, 1, 2, 3, 4]

Range.prototype.map(callback) -> Array

Maps the range to an array.

var arr = range(5).map((value, index) => Math.pow(value, 2));
// [0, 1, 4, 9, 16]

Range.prototype.reduce(callback, memo) -> *

Reduces the range to a value.

var val = range(5).reduce((memo, value, index) => memo + value, 0);
// 10

Range.prototype.each(callback) | Range.prototype.forEach(callback)

Iterates over each value in the range.

range(5).each(function(value, index) {
    console.log(value);
});

for-of

Lazily iterate over each value in the range.

for (let i of range(5)) {

}