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Diffstat (limited to 'addon-sdk/source/lib/sdk/util/sequence.js')
| -rw-r--r-- | addon-sdk/source/lib/sdk/util/sequence.js | 593 |
1 files changed, 0 insertions, 593 deletions
diff --git a/addon-sdk/source/lib/sdk/util/sequence.js b/addon-sdk/source/lib/sdk/util/sequence.js deleted file mode 100644 index 28e3de255..000000000 --- a/addon-sdk/source/lib/sdk/util/sequence.js +++ /dev/null @@ -1,593 +0,0 @@ -/* This Source Code Form is subject to the terms of the Mozilla Public - * License, v. 2.0. If a copy of the MPL was not distributed with this - * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ -"use strict"; - -module.metadata = { - "stability": "experimental" -}; - -// Disclamer: -// In this module we'll have some common argument / variable names -// to hint their type or behavior. -// -// - `f` stands for "function" that is intended to be side effect -// free. -// - `p` stands for "predicate" that is function which returns logical -// true or false and is intended to be side effect free. -// - `x` / `y` single item of the sequence. -// - `xs` / `ys` sequence of `x` / `y` items where `x` / `y` signifies -// type of the items in sequence, so sequence is not of the same item. -// - `_` used for argument(s) or variable(s) who's values are ignored. - -const { complement, flip, identity } = require("../lang/functional"); -const { isArray, isArguments, isMap, isSet, isGenerator, - isString, isBoolean, isNumber } = require("../lang/type"); - -const Sequence = function Sequence(iterator) { - if (!isGenerator(iterator)) { - throw TypeError("Expected generator argument"); - } - - this[Symbol.iterator] = iterator; -}; -exports.Sequence = Sequence; - -const polymorphic = dispatch => x => - x === null ? dispatch.null(null) : - x === void(0) ? dispatch.void(void(0)) : - isArray(x) ? (dispatch.array || dispatch.indexed)(x) : - isString(x) ? (dispatch.string || dispatch.indexed)(x) : - isArguments(x) ? (dispatch.arguments || dispatch.indexed)(x) : - isMap(x) ? dispatch.map(x) : - isSet(x) ? dispatch.set(x) : - isNumber(x) ? dispatch.number(x) : - isBoolean(x) ? dispatch.boolean(x) : - dispatch.default(x); - -const nogen = function*() {}; -const empty = () => new Sequence(nogen); -exports.empty = empty; - -const seq = polymorphic({ - null: empty, - void: empty, - array: identity, - string: identity, - arguments: identity, - map: identity, - set: identity, - default: x => x instanceof Sequence ? x : new Sequence(x) -}); -exports.seq = seq; - -// Function to cast seq to string. -const string = (...etc) => "".concat(...etc); -exports.string = string; - -// Function for casting seq to plain object. -const object = (...pairs) => { - let result = {}; - for (let [key, value] of pairs) - result[key] = value; - - return result; -}; -exports.object = object; - -// Takes `getEnumerator` function that returns `nsISimpleEnumerator` -// and creates lazy sequence of it's items. Note that function does -// not take `nsISimpleEnumerator` itslef because that would allow -// single iteration, which would not be consistent with rest of the -// lazy sequences. -const fromEnumerator = getEnumerator => seq(function* () { - const enumerator = getEnumerator(); - while (enumerator.hasMoreElements()) - yield enumerator.getNext(); -}); -exports.fromEnumerator = fromEnumerator; - -// Takes `object` and returns lazy sequence of own `[key, value]` -// pairs (does not include inherited and non enumerable keys). -const pairs = polymorphic({ - null: empty, - void: empty, - map: identity, - indexed: indexed => seq(function* () { - const count = indexed.length; - let index = 0; - while (index < count) { - yield [index, indexed[index]]; - index = index + 1; - } - }), - default: object => seq(function* () { - for (let key of Object.keys(object)) - yield [key, object[key]]; - }) -}); -exports.pairs = pairs; - -const names = polymorphic({ - null: empty, - void: empty, - default: object => seq(function*() { - for (let name of Object.getOwnPropertyNames(object)) { - yield name; - } - }) -}); -exports.names = names; - -const symbols = polymorphic({ - null: empty, - void: empty, - default: object => seq(function* () { - for (let symbol of Object.getOwnPropertySymbols(object)) { - yield symbol; - } - }) -}); -exports.symbols = symbols; - -const keys = polymorphic({ - null: empty, - void: empty, - indexed: indexed => seq(function* () { - const count = indexed.length; - let index = 0; - while (index < count) { - yield index; - index = index + 1; - } - }), - map: map => seq(function* () { - for (let [key, _] of map) - yield key; - }), - default: object => seq(function* () { - for (let key of Object.keys(object)) - yield key; - }) -}); -exports.keys = keys; - - -const values = polymorphic({ - null: empty, - void: empty, - set: identity, - indexed: indexed => seq(function* () { - const count = indexed.length; - let index = 0; - while (index < count) { - yield indexed[index]; - index = index + 1; - } - }), - map: map => seq(function* () { - for (let [_, value] of map) yield value; - }), - default: object => seq(function* () { - for (let key of Object.keys(object)) yield object[key]; - }) -}); -exports.values = values; - - - -// Returns a lazy sequence of `x`, `f(x)`, `f(f(x))` etc. -// `f` must be free of side-effects. Note that returned -// sequence is infinite so it must be consumed partially. -// -// Implements clojure iterate: -// http://clojuredocs.org/clojure_core/clojure.core/iterate -const iterate = (f, x) => seq(function* () { - let state = x; - while (true) { - yield state; - state = f(state); - } -}); -exports.iterate = iterate; - -// Returns a lazy sequence of the items in sequence for which `p(item)` -// returns `true`. `p` must be free of side-effects. -// -// Implements clojure filter: -// http://clojuredocs.org/clojure_core/clojure.core/filter -const filter = (p, sequence) => seq(function* () { - if (sequence !== null && sequence !== void(0)) { - for (let item of sequence) { - if (p(item)) - yield item; - } - } -}); -exports.filter = filter; - -// Returns a lazy sequence consisting of the result of applying `f` to the -// set of first items of each sequence, followed by applying f to the set -// of second items in each sequence, until any one of the sequences is -// exhausted. Any remaining items in other sequences are ignored. Function -// `f` should accept number-of-sequences arguments. -// -// Implements clojure map: -// http://clojuredocs.org/clojure_core/clojure.core/map -const map = (f, ...sequences) => seq(function* () { - const count = sequences.length; - // Optimize a single sequence case - if (count === 1) { - let [sequence] = sequences; - if (sequence !== null && sequence !== void(0)) { - for (let item of sequence) - yield f(item); - } - } - else { - // define args array that will be recycled on each - // step to aggregate arguments to be passed to `f`. - let args = []; - // define inputs to contain started generators. - let inputs = []; - - let index = 0; - while (index < count) { - inputs[index] = sequences[index][Symbol.iterator](); - index = index + 1; - } - - // Run loop yielding of applying `f` to the set of - // items at each step until one of the `inputs` is - // exhausted. - let done = false; - while (!done) { - let index = 0; - let value = void(0); - while (index < count && !done) { - ({ done, value } = inputs[index].next()); - - // If input is not exhausted yet store value in args. - if (!done) { - args[index] = value; - index = index + 1; - } - } - - // If none of the inputs is exhasted yet, `args` contain items - // from each input so we yield application of `f` over them. - if (!done) - yield f(...args); - } - } -}); -exports.map = map; - -// Returns a lazy sequence of the intermediate values of the reduction (as -// per reduce) of sequence by `f`, starting with `initial` value if provided. -// -// Implements clojure reductions: -// http://clojuredocs.org/clojure_core/clojure.core/reductions -const reductions = (...params) => { - const count = params.length; - let hasInitial = false; - let f, initial, source; - if (count === 2) { - [f, source] = params; - } - else if (count === 3) { - [f, initial, source] = params; - hasInitial = true; - } - else { - throw Error("Invoked with wrong number of arguments: " + count); - } - - const sequence = seq(source); - - return seq(function* () { - let started = hasInitial; - let result = void(0); - - // If initial is present yield it. - if (hasInitial) - yield (result = initial); - - // For each item of the sequence accumulate new result. - for (let item of sequence) { - // If nothing has being yield yet set result to first - // item and yield it. - if (!started) { - started = true; - yield (result = item); - } - // Otherwise accumulate new result and yield it. - else { - yield (result = f(result, item)); - } - } - - // If nothing has being yield yet it's empty sequence and no - // `initial` was provided in which case we need to yield `f()`. - if (!started) - yield f(); - }); -}; -exports.reductions = reductions; - -// `f` should be a function of 2 arguments. If `initial` is not supplied, -// returns the result of applying `f` to the first 2 items in sequence, then -// applying `f` to that result and the 3rd item, etc. If sequence contains no -// items, `f` must accept no arguments as well, and reduce returns the -// result of calling f with no arguments. If sequence has only 1 item, it -// is returned and `f` is not called. If `initial` is supplied, returns the -// result of applying `f` to `initial` and the first item in sequence, then -// applying `f` to that result and the 2nd item, etc. If sequence contains no -// items, returns `initial` and `f` is not called. -// -// Implements clojure reduce: -// http://clojuredocs.org/clojure_core/clojure.core/reduce -const reduce = (...args) => { - const xs = reductions(...args); - let x; - for (x of xs) void(0); - return x; -}; -exports.reduce = reduce; - -const each = (f, sequence) => { - for (let x of seq(sequence)) void(f(x)); -}; -exports.each = each; - - -const inc = x => x + 1; -// Returns the number of items in the sequence. `count(null)` && `count()` -// returns `0`. Also works on strings, arrays, Maps & Sets. - -// Implements clojure count: -// http://clojuredocs.org/clojure_core/clojure.core/count -const count = polymorphic({ - null: _ => 0, - void: _ => 0, - indexed: indexed => indexed.length, - map: map => map.size, - set: set => set.size, - default: xs => reduce(inc, 0, xs) -}); -exports.count = count; - -// Returns `true` if sequence has no items. - -// Implements clojure empty?: -// http://clojuredocs.org/clojure_core/clojure.core/empty_q -const isEmpty = sequence => { - // Treat `null` and `undefined` as empty sequences. - if (sequence === null || sequence === void(0)) - return true; - - // If contains any item non empty so return `false`. - for (let _ of sequence) - return false; - - // If has not returned yet, there was nothing to iterate - // so it's empty. - return true; -}; -exports.isEmpty = isEmpty; - -const and = (a, b) => a && b; - -// Returns true if `p(x)` is logical `true` for every `x` in sequence, else -// `false`. -// -// Implements clojure every?: -// http://clojuredocs.org/clojure_core/clojure.core/every_q -const isEvery = (p, sequence) => { - if (sequence !== null && sequence !== void(0)) { - for (let item of sequence) { - if (!p(item)) - return false; - } - } - return true; -}; -exports.isEvery = isEvery; - -// Returns the first logical true value of (p x) for any x in sequence, -// else `null`. -// -// Implements clojure some: -// http://clojuredocs.org/clojure_core/clojure.core/some -const some = (p, sequence) => { - if (sequence !== null && sequence !== void(0)) { - for (let item of sequence) { - if (p(item)) - return true; - } - } - return null; -}; -exports.some = some; - -// Returns a lazy sequence of the first `n` items in sequence, or all items if -// there are fewer than `n`. -// -// Implements clojure take: -// http://clojuredocs.org/clojure_core/clojure.core/take -const take = (n, sequence) => n <= 0 ? empty() : seq(function* () { - let count = n; - for (let item of sequence) { - yield item; - count = count - 1; - if (count === 0) break; - } -}); -exports.take = take; - -// Returns a lazy sequence of successive items from sequence while -// `p(item)` returns `true`. `p` must be free of side-effects. -// -// Implements clojure take-while: -// http://clojuredocs.org/clojure_core/clojure.core/take-while -const takeWhile = (p, sequence) => seq(function* () { - for (let item of sequence) { - if (!p(item)) - break; - - yield item; - } -}); -exports.takeWhile = takeWhile; - -// Returns a lazy sequence of all but the first `n` items in -// sequence. -// -// Implements clojure drop: -// http://clojuredocs.org/clojure_core/clojure.core/drop -const drop = (n, sequence) => seq(function* () { - if (sequence !== null && sequence !== void(0)) { - let count = n; - for (let item of sequence) { - if (count > 0) - count = count - 1; - else - yield item; - } - } -}); -exports.drop = drop; - -// Returns a lazy sequence of the items in sequence starting from the -// first item for which `p(item)` returns falsy value. -// -// Implements clojure drop-while: -// http://clojuredocs.org/clojure_core/clojure.core/drop-while -const dropWhile = (p, sequence) => seq(function* () { - let keep = false; - for (let item of sequence) { - keep = keep || !p(item); - if (keep) yield item; - } -}); -exports.dropWhile = dropWhile; - -// Returns a lazy sequence representing the concatenation of the -// suplied sequences. -// -// Implements clojure conact: -// http://clojuredocs.org/clojure_core/clojure.core/concat -const concat = (...sequences) => seq(function* () { - for (let sequence of sequences) - for (let item of sequence) - yield item; -}); -exports.concat = concat; - -// Returns the first item in the sequence. -// -// Implements clojure first: -// http://clojuredocs.org/clojure_core/clojure.core/first -const first = sequence => { - if (sequence !== null && sequence !== void(0)) { - for (let item of sequence) - return item; - } - return null; -}; -exports.first = first; - -// Returns a possibly empty sequence of the items after the first. -// -// Implements clojure rest: -// http://clojuredocs.org/clojure_core/clojure.core/rest -const rest = sequence => drop(1, sequence); -exports.rest = rest; - -// Returns the value at the index. Returns `notFound` or `undefined` -// if index is out of bounds. -const nth = (xs, n, notFound) => { - if (n >= 0) { - if (isArray(xs) || isArguments(xs) || isString(xs)) { - return n < xs.length ? xs[n] : notFound; - } - else if (xs !== null && xs !== void(0)) { - let count = n; - for (let x of xs) { - if (count <= 0) - return x; - - count = count - 1; - } - } - } - return notFound; -}; -exports.nth = nth; - -// Return the last item in sequence, in linear time. -// If `sequence` is an array or string or arguments -// returns in constant time. -// Implements clojure last: -// http://clojuredocs.org/clojure_core/clojure.core/last -const last = polymorphic({ - null: _ => null, - void: _ => null, - indexed: indexed => indexed[indexed.length - 1], - map: xs => reduce((_, x) => x, xs), - set: xs => reduce((_, x) => x, xs), - default: xs => reduce((_, x) => x, xs) -}); -exports.last = last; - -// Return a lazy sequence of all but the last `n` (default 1) items -// from the give `xs`. -// -// Implements clojure drop-last: -// http://clojuredocs.org/clojure_core/clojure.core/drop-last -const dropLast = flip((xs, n=1) => seq(function* () { - let ys = []; - for (let x of xs) { - ys.push(x); - if (ys.length > n) - yield ys.shift(); - } -})); -exports.dropLast = dropLast; - -// Returns a lazy sequence of the elements of `xs` with duplicates -// removed -// -// Implements clojure distinct -// http://clojuredocs.org/clojure_core/clojure.core/distinct -const distinct = sequence => seq(function* () { - let items = new Set(); - for (let item of sequence) { - if (!items.has(item)) { - items.add(item); - yield item; - } - } -}); -exports.distinct = distinct; - -// Returns a lazy sequence of the items in `xs` for which -// `p(x)` returns false. `p` must be free of side-effects. -// -// Implements clojure remove -// http://clojuredocs.org/clojure_core/clojure.core/remove -const remove = (p, xs) => filter(complement(p), xs); -exports.remove = remove; - -// Returns the result of applying concat to the result of -// `map(f, xs)`. Thus function `f` should return a sequence. -// -// Implements clojure mapcat -// http://clojuredocs.org/clojure_core/clojure.core/mapcat -const mapcat = (f, sequence) => seq(function* () { - const sequences = map(f, sequence); - for (let sequence of sequences) - for (let item of sequence) - yield item; -}); -exports.mapcat = mapcat; |