Cagen

Number of Case Generator for TypeScript.

Symbol	Class
A x B x ... x Z	CartesianProduct
n!	Factorial
nPr	Permutation
n∏r	RepeatedPermutation
nHr	RepeatedCombination
nCr	Combination

• API Documents
• Guide Documents

Usage

Installation

npm install --save cagen

Common Features

namespace cagen.base
{
    export interface IForwardGenerator
    {
        // FREQUENCE ACCESSORS
        size(): number;
        begin(): Iterator;
        end(): Iterator;

        // ES2015, THEN FOR-OF ITERATION IS ALSO POSSIBLE
        [Symbol.iterator]: IterableIterator<number[]>;
    }

    export interface Iterator
    {
        readonly value: number[];

        next(): Iterator;
        equals(obj: Iterator): boolean;
    }
}

import { CartesianProduct } from "cagen";

function main(): void
{
    let generator = new CartesianProduct(5, 4); // 5C4
    console.log("n(5C4) =", generator.size());

    for (let it = generator.begin(); !it.equals(generator.end()); it = it.next())
    {
        let aCase: number[] = it.value;
        console.log("  -", aCase);
    }
}
main();

for (let aCase of generator)
    console.log("  -", aCase);

Random Accessor

namespace cagen.base
{
    export abstract class ArrayGenerator
        implements IForwardGenerator<Iterator>
    {
        at(index: number): Array<number>;
    }
}

Most of Case Generator classes, except combination classes, provide a random accessor at(). By that method at(), you can access to a specific case through not full iteration, but the special index number.

• Permutation
• Factorial
• RepeatedPermutation
• CartesianProduct
• Combination
• RepeatedCombination

import { Permutation } from "cagen";

function main(): void
{
    let generator = new Permutation(7, 3);

    console.log( generator.at(13) );
    console.log( generator.at(31) );
    console.log( generator.at(9999) ); // throw an std.OutOfRange error.
}
main();