dabbjs/dist/lib/generics.js

general javascript library

/**
 * LINQ select many
 * @template TIn, TOut
 * @param {TIn} input array of input values
 * @param selectListFn extractor function (t: {@link TIn}) => {@link TOut}[]
 * @returns array {@link TOut}[]
 */
export const selectMany = (input, selectListFn) => input.reduce((out, inx) => {
    out.push(...selectListFn(inx));
    return out;
}, new Array());
/**
 * return unique items in array
 * @param x array
 */
export const unique = (x) => x.filter((elem, index) => x.indexOf(elem) === index);
/**
 *
 * @param x
 * @param y
 * @returns
 */
export const union = (x, y) => unique(x.concat(y));
/**
 * groups an array by a function key
 * @param list Array of items of type `T`
 * @param getKey grouping key function
 * @returns a group object with keys and array of same key values
 */
export const groupBy = (list, getKey) => {
    let obj = {};
    obj.length = 0;
    return list.reduce((previous, currentItem) => {
        const key = getKey(currentItem);
        if (!previous[key]) {
            previous[key] = [];
            previous.length++;
        }
        previous[key].push(currentItem);
        return previous;
    }, obj);
};
export function setWritableProperty(obj, key, // <-- restrict to writable keys
value) {
    obj[key] = value;
}
/*
let x = { a: 1, b: 2, c: 3, d: 4 };

getProperty(x, "a");
getProperty(x, "m");
*/
/**
 * gets an existing object property
 * @param obj object
 * @param key a key inside object
 * @returns
 */
export function getProperty(obj, key) {
    return obj[key];
}
/**
 * sets an existing object property value
 * @param obj object
 * @param {Key} key a key inside object
 * @param {Type[Key]} value value
 * @returns object for linking
 */
export function setProperty(obj, key, value) {
    obj[key] = value;
    //
    return obj;
}
// const f: HTMLDialog = <any>void 0;
// setProperty(f, 'header', "The Header");
// const setPropertyAttr = (dialog: HTMLDialog, prop: keyof HTMLDialog, value: any) => {
// 	if (dialog.hasAttribute("non-cancellable")) {
// 		setProperty(dialog, prop, false);
// 		dialog[prop] = false;
// 		dialog.removeAttribute("non-cancellable")
// 	}
// }