types.js/Array.js
Alex A. Naanou 891f332fa2 added sort to most types that have ordered elements...
Signed-off-by: Alex A. Naanou <alex.nanou@gmail.com>
2020-10-07 16:46:59 +03:00

323 lines
8.8 KiB
JavaScript

/**********************************************************************
*
*
*
**********************************************/ /* c8 ignore next 2 */
((typeof define)[0]=='u'?function(f){module.exports=f(require)}:define)
(function(require){ var module={} // make module AMD/node compatible...
/*********************************************************************/
/*********************************************************************/
// Array.prototype.flat polyfill...
//
// NOTE: .flat(..) is not yet supported in IE/Edge...
Array.prototype.flat
|| (Array.prototype.flat = function(depth){
depth = typeof(depth) == typeof(123) ? depth : 1
return this.reduce(function(res, e){
return res.concat(e instanceof Array && depth > 0 ?
e.flat(depth-1)
: [e]) }, []) })
// Array.prototype.includes polyfill...
//
Array.prototype.includes
|| (Array.prototype.includes = function(value){
return this.indexOf(value) >= 0 })
// first/last element access short-hands...
//
// .first()
// .last()
// -> elem
//
// .first(value)
// .last(value)
// -> array
//
// NOTE: setting a value will overwrite an existing first/last value.
// NOTE: for an empty array both .first(..)/.last(..) will return undefined
// when getting a value and set the 0'th value when setting...
Array.prototype.first
|| (Array.prototype.first = function(value){
return arguments.length > 0 ?
((this[0] = value), this)
: this[0]})
Array.prototype.last
|| (Array.prototype.last = function(value){
return arguments.length > 0 ?
((this[this.length - 1 || 0] = value), this)
: this[this.length - 1]})
/*/ XXX not yet sure should these be funcs or props...
'first' in Array.prototype
|| Object.defineProperty(Array.prototype, 'first', {
enumerable: false,
get : function () {
return this[0] },
set : function(value){
this[0] = value
return this }, })
'last' in Array.prototype
|| Object.defineProperty(Array.prototype, 'last', {
enumerable: false,
get : function () {
return this[this.length - 1] },
set : function(value){
this[this.length - 1 || 0] = value
return this }, })
//*/
// Compact a sparse array...
//
// NOTE: this will not compact in-place.
Array.prototype.compact = function(){
return this.filter(function(){ return true }) }
// like .length but for sparse arrays will return the element count...
'len' in Array.prototype
|| Object.defineProperty(Array.prototype, 'len', {
get : function () {
return Object.keys(this).length
},
set : function(val){},
})
// Return an array with duplicate elements removed...
//
// NOTE: order is preserved...
Array.prototype.unique = function(normalize){
return normalize ?
[...new Map(this.map(function(e){ return [normalize(e), e] })).values()]
: [...new Set(this)] }
Array.prototype.tailUnique = function(normalize){
return this
.slice()
.reverse()
.unique(normalize)
.reverse() }
// Compare two arrays...
//
// XXX unify this with ./Object.js (.match(..)) and diff.js
Array.prototype.cmp = function(other){
if(this === other){
return true }
if(this.length != other.length){
return false }
for(var i=0; i<this.length; i++){
if(this[i] != other[i]){
return false } }
return true }
// Compare two Arrays as sets...
//
// NOTE: this will ignore order and repeating elments...
Array.prototype.setCmp = function(other){
return this === other
|| (new Set([...this, ...other])).length == (new Set(this)).length }
// Sort as the other array...
//
// This will sort the intersecting items in the head keeping the rest
// of the items in the same relative order...
//
// NOTE: if an item is in the array multiple times only the first index
// is used...
Array.prototype.sortAs = function(other){
// NOTE: the memory overhead here is better than the time overhead
// when using .indexOf(..)...
other = other.toMap()
var orig = this.toMap()
return this.sort(function(a, b){
var i = other.get(a)
var j = other.get(b)
return i == null && j == null ?
orig.get(a) - orig.get(b)
: i == null ?
1
: j == null ?
-1
: i - j }) }
// Same as .sortAs(..) but will not change indexes of items not in other...
//
// XXX not sure if this is the best way to do this...
Array.prototype.inplaceSortAs = function(other){
// sort only the intersection...
var sorted = this
.filter(function(e){
return other.includes(e) })
.sortAs(other)
// zip the sorted items back into this...
this.forEach(function(e, i, l){
other.includes(e)
&& (l[i] = sorted.shift()) })
return this }
// Equivalent to .map(..) / .filter(..) / .reduce(..) that process the
// contents in chunks asynchronously...
//
// .mapChunks(func)
// .mapChunks(chunk_size, func)
// .mapChunks([item_handler, chunk_handler])
// .mapChunks(chunk_size, [item_handler, chunk_handler])
// -> promise(list)
//
// .filterChunks(func)
// .filterChunks(chunk_size, func)
// .filterChunks([item_handler, chunk_handler])
// .filterChunks(chunk_size, [item_handler, chunk_handler])
// -> promise(list)
//
// .reduceChunks(func, res)
// .reduceChunks(chunk_size, func, res)
// .reduceChunks([item_handler, chunk_handler], res)
// .reduceChunks(chunk_size, [item_handler, chunk_handler], res)
// -> promise(res)
//
//
// chunk_handler(chunk, result, offset)
//
//
// chunk_size can be:
// 20 - chunk size
// '20' - chunk size
// '20C' - number of chunks
//
//
// The main goal of this is to not block the runtime while processing a
// very long array by interrupting the processing with a timeout...
//
var makeChunkIter = function(iter, wrapper){
wrapper = wrapper
|| function(res, func, array, e){
return func.call(this, e[1], e[0], array) }
return function(size, func, ...rest){
var that = this
var args = [...arguments]
size = (args[0] instanceof Function
|| args[0] instanceof Array) ?
(this.CHUNK_SIZE || 50)
: args.shift()
size = typeof(size) == typeof('str') ?
// number of chunks...
(size.trim().endsWith('c') || size.trim().endsWith('C') ?
Math.round(this.length / (parseInt(size) || 1)) || 1
: parseInt(size))
: size
var postChunk
func = args.shift()
;[func, postChunk] = func instanceof Array ? func : [func]
rest = args
var res = []
var _wrapper = wrapper.bind(this, res, func, this)
return new Promise(function(resolve, reject){
var next = function(chunks){
setTimeout(function(){
var chunk, val
res.push(
val = (chunk = chunks.shift())[iter](_wrapper, ...rest))
postChunk
&& postChunk.call(that,
chunk.map(function([i, v]){ return v }),
val,
chunk[0][0])
// stop condition...
chunks.length == 0 ?
resolve(res.flat(2))
: next(chunks) }, 0) }
next(that
// split the array into chunks...
.reduce(function(res, e, i){
var c = res.slice(-1)[0]
c.length >= size ?
// initial element in chunk...
res.push([[i, e]])
// rest...
: c.push([i, e])
return res }, [[]])) }) } }
Array.prototype.CHUNK_SIZE = 50
Array.prototype.mapChunks = makeChunkIter('map')
Array.prototype.filterChunks = makeChunkIter('map',
function(res, func, array, e){
return !!func.call(this, e[1], e[0], array) ? [e[1]] : [] })
Array.prototype.reduceChunks = makeChunkIter('reduce',
function(total, func, array, res, e){
return func.call(this,
total.length > 0 ?
total.pop()
: res,
e[1], e[0], array) })
// Convert an array to object...
//
// Format:
// {
// <item>: <index>,
// ...
// }
//
// NOTE: items should be strings, other types will get converted to
// strings and thus may mess things up.
// NOTE: this will forget repeating items...
// NOTE: normalize will slow things down...
Array.prototype.toKeys = function(normalize){
return normalize ?
this.reduce(function(r, e, i){
r[normalize(e)] = i
return r }, {})
: this.reduce(function(r, e, i){
r[e] = i
return r }, {}) }
// Convert an array to a map...
//
// This is similar to Array.prototype.toKeys(..) but does not restrict
// value type to string.
//
// Format:
// Map([
// [<item>, <index>],
// ...
// ])
//
// NOTE: this will forget repeating items...
// NOTE: normalize will slow things down...
Array.prototype.toMap = function(normalize){
return normalize ?
this
.reduce(function(m, e, i){
m.set(normalize(e), i)
return m }, new Map())
: this
.reduce(function(m, e, i){
m.set(e, i)
return m }, new Map()) }
/**********************************************************************
* vim:set ts=4 sw=4 : */ return module })