Table of contents

• Table of contents
• Introduction
• API
  • PyRange
  • pyRange()
  • map()
  • mapAsync()
  • forEach()
  • forEachAsync()
  • toIterator()
  • toArray()
  • fill()
  • toObject()

Introduction

• PyRange creates an object that stores only 3 values (start, stop, step) and corresponding methods (map, forEach, fill, toArray, toIterator, ...).
• Inspired by range function for Python.

API

PyRange

const r = new PyRange(5, 10, 2);

console.log(r);
// PyRange { _start: 5, _stop: 10, _step: 2 }

console.log(r.toArray());
// [ 5, 7, 9 ]

pyRange()

• pyRange(stop:number)

console.log(pyRange(10));
// PyRange { _start: 0, _stop: 10, _step: 1 }

console.log(pyRange(-50));
// PyRange { _start: 0, _stop: -50, _step: -1 }

• pyRange(start:number, stop:number)

console.log(pyRange(0, 20));
// PyRange { _start: 0, _stop: 20, _step: 1 }

console.log(pyRange(3, -5));
// PyRange { _start: 3, _stop: -5, _step: -1 }

• pyRange(start:number, stop:number, step:number)

console.log(pyRange(0, 12, 3));
// PyRange { _start: 0, _stop: 12, _step: 3 }

console.log(pyRange(0, -12, -3));
//PyRange { _start: 0, _stop: -12, _step: -3 }

map()

It works similar to Array.prototype.map();

const elements: string[] = pyRange(0, -12, -3).map((value, index) => {
    return `index= ${index}, value= ${value}`;
});

console.log('[map]', elements);
// [map] [
//     'index= 0, value= 0',
//     'index= 1, value= -3',
//     'index= 2, value= -6',
//     'index= 3, value= -9'
// ]

mapAsync()

const elements = await pyRange(0, 12, 4).mapAsync(async (value, index) => {
    return { index, value };
});

console.log('[elements]', elements);
// [elements] [
//     { index: 0, value: 0 },
//     { index: 1, value: 4 },
//     { index: 2, value: 8 }
// ]

forEach()

It works similar to Array.prototype.forEach().

pyRange(3).forEach((value, index) => {
    console.log('[forEach]', `value= ${value} ; index= ${index}`);
});
// [forEach] value= 0 ; index= 0
// [forEach] value= 1 ; index= 1
// [forEach] value= 2 ; index= 2

forEachAsync()

await pyRange(3, 6).forEachAsync(async (value, index) => {
    console.log('[forEachAsync]', `value= ${value} ; index= ${index}`);
});
// [forEachAsync] value= 3 ; index= 0
// [forEachAsync] value= 4 ; index= 1
// [forEachAsync] value= 5 ; index= 2

toIterator()

for (const value of pyRange(5, 8).toIterator()) {
    console.log('[for-of]', `value= ${value}`);
}
// [for-of] value= 5
// [for-of] value= 6
// [for-of] value= 7

console.log('[toArray]', pyRange(0, 12, 3).toArray());
// [toArray] [ 0, 3, 6, 9 ]

console.log('[fill]', pyRange(5).fill(0));
// [fill] [ 0, 0, 0, 0, 0 ]

toArray()

console.log('[toArray]', pyRange(0, 12, 3).toArray());
// [toArray] [ 0, 3, 6, 9 ]

fill()

console.log('[fill]', pyRange(5).fill(0));
// [fill] [ 0, 0, 0, 0, 0 ]


console.log(
    '[fill]',
    pyRange(5).fill({
        type: 'Object',
        value: 'Some values',
    }),
);
// [fill] [
//     { type: 'Object', value: 'Some values' },
//     { type: 'Object', value: 'Some values' },
//     { type: 'Object', value: 'Some values' },
//     { type: 'Object', value: 'Some values' },
//     { type: 'Object', value: 'Some values' }
// ]

toObject()

console.log(pyRange(5, 10).toObject());
// { start: 5, stop: 10, step: 1 }