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Diffstat (limited to 'node_modules/array-uniq/index.js')
-rw-r--r-- | node_modules/array-uniq/index.js | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/node_modules/array-uniq/index.js b/node_modules/array-uniq/index.js new file mode 100644 index 000000000..edd09f811 --- /dev/null +++ b/node_modules/array-uniq/index.js @@ -0,0 +1,62 @@ +'use strict'; + +// there's 3 implementations written in increasing order of efficiency + +// 1 - no Set type is defined +function uniqNoSet(arr) { + var ret = []; + + for (var i = 0; i < arr.length; i++) { + if (ret.indexOf(arr[i]) === -1) { + ret.push(arr[i]); + } + } + + return ret; +} + +// 2 - a simple Set type is defined +function uniqSet(arr) { + var seen = new Set(); + return arr.filter(function (el) { + if (!seen.has(el)) { + seen.add(el); + return true; + } + + return false; + }); +} + +// 3 - a standard Set type is defined and it has a forEach method +function uniqSetWithForEach(arr) { + var ret = []; + + (new Set(arr)).forEach(function (el) { + ret.push(el); + }); + + return ret; +} + +// V8 currently has a broken implementation +// https://github.com/joyent/node/issues/8449 +function doesForEachActuallyWork() { + var ret = false; + + (new Set([true])).forEach(function (el) { + ret = el; + }); + + return ret === true; +} + +if ('Set' in global) { + if (typeof Set.prototype.forEach === 'function' && doesForEachActuallyWork()) { + module.exports = uniqSetWithForEach; + } else { + module.exports = uniqSet; + } +} else { + module.exports = uniqNoSet; +} |