Transducer to transform and convert native JS iterable data types

transducer.js

// MAIN iterator

function isInstanceOf(output, input, instanceOfType) {
    return output ? output instanceof instanceOfType : input instanceof instanceOfType
}


function asSet(data) {
    return new Set(data.values())
}


function asArray(data) {
    return Array.from(data.values());
}


function asIterable(func, convertor) {
    return function(...args) {
        response = func(...args)
        return convertor(response);
    }
}


function reduce(input, transformator) {

    let response = new Map();

    for (kv of input.entries()) {
        response = transformator((result, [key, value]) => {
            return result.set(key, value);
        })(response, kv)
    }

    return response;

}


const reduceToSet = asIterable(reduce, asSet);
const reduceToArray = asIterable(reduce, asArray);


// REDUCERS

const mapReducer = (f) => (reducing) => (result, input) => reducing(result, f(input));

const filterReducer = (predicate) => (reducing) => (result, input) => predicate(input) ? reducing(result, input) : result;


// TRANSFORMATORS

// Mappers
const stringifyMapper = mapReducer(([key, value]) => {
    return [key, `${value}`];
})

const addMapper = (count) => mapReducer(([key, value]) => {
    return [key, value + count];
});

const convertToJSXComponentExample = mapReducer(([key, value]) => {
    return [
        key,
        `<div id=${key}>${value}</div>`
    ]
})

// Filters
const evenFilter = filterReducer(([key, value]) => (value % 2 === 0));


// Transformators are composable

const addStringifyFilterTransformator = R.compose(
    addMapper(1),
    stringifyMapper,
    evenFilter
);

const evenToJSXTransformator = R.compose(
    addMapper(1),
    evenFilter,
    convertToJSXComponentExample
)


// PLAYGROUND

const arr = [ 1, 2, 3 ];
const map = new Map([ ['id1', 1], ['id2', 2], ['id3', 3] ]);
const set = new Set([1, 2, 3]);


console.group('United data transformation across native JS iterable data types')

// convert to set
asSet(reduce( arr, addStringifyFilterTransformator))
reduceToSet( arr, addStringifyFilterTransformator)

// convert to Array
asArray(reduce( arr, addStringifyFilterTransformator))
reduceToArray( arr, addStringifyFilterTransformator)

// plain data
reduce( arr, addStringifyFilterTransformator)


console.log(
    reduce( map, addStringifyFilterTransformator, [] )
);

console.log(
    reduce( set, addStringifyFilterTransformator, [] )
);

console.log(
    reduce( arr, addStringifyFilterTransformator, new Map() )
);

console.log(
    reduce( map, addStringifyFilterTransformator, new Map() )
);

console.log(
    reduce( set, addStringifyFilterTransformator, new Map() )
);

console.log(
    reduce( arr, addStringifyFilterTransformator, new Set() )
);

console.log(
    reduce( map, addStringifyFilterTransformator, new Set() )
);

console.log(
    reduce( set, addStringifyFilterTransformator, new Set() )
);

console.groupEnd()


console.group('Output argument is optional')

console.log(
    reduce(arr, addStringifyFilterTransformator)
);

console.log(
    reduce(map, addStringifyFilterTransformator)
);

console.log(
    reduce(set, addStringifyFilterTransformator)
);

console.groupEnd()


console.group('Filter and convert')

console.log(
    reduce(arr, evenToJSXTransformator)
);

console.log(
    reduce(map, evenToJSXTransformator)
);

console.log(
    reduce(set, evenToJSXTransformator)
);

console.groupEnd()