diff options
author | Florian Dold <florian.dold@gmail.com> | 2017-08-14 05:01:11 +0200 |
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committer | Florian Dold <florian.dold@gmail.com> | 2017-08-14 05:02:09 +0200 |
commit | 363723fc84f7b8477592e0105aeb331ec9a017af (patch) | |
tree | 29f92724f34131bac64d6a318dd7e30612e631c7 /node_modules/d/lazy.js | |
parent | 5634e77ad96bfe1818f6b6ee70b7379652e5487f (diff) |
node_modules
Diffstat (limited to 'node_modules/d/lazy.js')
-rw-r--r-- | node_modules/d/lazy.js | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/node_modules/d/lazy.js b/node_modules/d/lazy.js new file mode 100644 index 000000000..d75b34b77 --- /dev/null +++ b/node_modules/d/lazy.js @@ -0,0 +1,117 @@ +'use strict'; + +var map = require('es5-ext/object/map') + , isCallable = require('es5-ext/object/is-callable') + , validValue = require('es5-ext/object/valid-value') + , contains = require('es5-ext/string/#/contains') + + , call = Function.prototype.call + , defineProperty = Object.defineProperty + , getOwnPropertyDescriptor = Object.getOwnPropertyDescriptor + , getPrototypeOf = Object.getPrototypeOf + , hasOwnProperty = Object.prototype.hasOwnProperty + , cacheDesc = { configurable: false, enumerable: false, writable: false, + value: null } + , define; + +define = function (name, options) { + var value, dgs, cacheName, desc, writable = false, resolvable + , flat; + options = Object(validValue(options)); + cacheName = options.cacheName; + flat = options.flat; + if (cacheName == null) cacheName = name; + delete options.cacheName; + value = options.value; + resolvable = isCallable(value); + delete options.value; + dgs = { configurable: Boolean(options.configurable), + enumerable: Boolean(options.enumerable) }; + if (name !== cacheName) { + dgs.get = function () { + if (hasOwnProperty.call(this, cacheName)) return this[cacheName]; + cacheDesc.value = resolvable ? call.call(value, this, options) : value; + cacheDesc.writable = writable; + defineProperty(this, cacheName, cacheDesc); + cacheDesc.value = null; + if (desc) defineProperty(this, name, desc); + return this[cacheName]; + }; + } else if (!flat) { + dgs.get = function self() { + var ownDesc; + if (hasOwnProperty.call(this, name)) { + ownDesc = getOwnPropertyDescriptor(this, name); + // It happens in Safari, that getter is still called after property + // was defined with a value, following workarounds that + // While in IE11 it may happen that here ownDesc is undefined (go figure) + if (ownDesc) { + if (ownDesc.hasOwnProperty('value')) return ownDesc.value; + if ((typeof ownDesc.get === 'function') && (ownDesc.get !== self)) { + return ownDesc.get.call(this); + } + return value; + } + } + desc.value = resolvable ? call.call(value, this, options) : value; + defineProperty(this, name, desc); + desc.value = null; + return this[name]; + }; + } else { + dgs.get = function self() { + var base = this, ownDesc; + if (hasOwnProperty.call(this, name)) { + // It happens in Safari, that getter is still called after property + // was defined with a value, following workarounds that + ownDesc = getOwnPropertyDescriptor(this, name); + if (ownDesc.hasOwnProperty('value')) return ownDesc.value; + if ((typeof ownDesc.get === 'function') && (ownDesc.get !== self)) { + return ownDesc.get.call(this); + } + } + while (!hasOwnProperty.call(base, name)) base = getPrototypeOf(base); + desc.value = resolvable ? call.call(value, base, options) : value; + defineProperty(base, name, desc); + desc.value = null; + return base[name]; + }; + } + dgs.set = function (value) { + if (hasOwnProperty.call(this, name)) { + throw new TypeError("Cannot assign to lazy defined '" + name + "' property of " + this); + } + dgs.get.call(this); + this[cacheName] = value; + }; + if (options.desc) { + desc = { + configurable: contains.call(options.desc, 'c'), + enumerable: contains.call(options.desc, 'e') + }; + if (cacheName === name) { + desc.writable = contains.call(options.desc, 'w'); + desc.value = null; + } else { + writable = contains.call(options.desc, 'w'); + desc.get = dgs.get; + desc.set = dgs.set; + } + delete options.desc; + } else if (cacheName === name) { + desc = { + configurable: Boolean(options.configurable), + enumerable: Boolean(options.enumerable), + writable: Boolean(options.writable), + value: null + }; + } + delete options.configurable; + delete options.enumerable; + delete options.writable; + return dgs; +}; + +module.exports = function (props) { + return map(props, function (desc, name) { return define(name, desc); }); +}; |