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author | Florian Dold <florian.dold@gmail.com> | 2017-05-28 00:38:50 +0200 |
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committer | Florian Dold <florian.dold@gmail.com> | 2017-05-28 00:40:43 +0200 |
commit | 7fff4499fd915bcea3fa93b1aa8b35f4fe7a6027 (patch) | |
tree | 6de9a1aebd150a23b7f8c273ec657a5d0a18fe3e /node_modules/slide/lib/async-map.js | |
parent | 963b7a41feb29cc4be090a2446bdfe0c1f1bcd81 (diff) |
add linting (and some initial fixes)
Diffstat (limited to 'node_modules/slide/lib/async-map.js')
-rw-r--r-- | node_modules/slide/lib/async-map.js | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/node_modules/slide/lib/async-map.js b/node_modules/slide/lib/async-map.js new file mode 100644 index 000000000..ccf345f3c --- /dev/null +++ b/node_modules/slide/lib/async-map.js @@ -0,0 +1,54 @@ + +/* +usage: + +// do something to a list of things +asyncMap(myListOfStuff, function (thing, cb) { doSomething(thing.foo, cb) }, cb) +// do more than one thing to each item +asyncMap(list, fooFn, barFn, cb) + +*/ + +module.exports = asyncMap + +function asyncMap () { + var steps = Array.prototype.slice.call(arguments) + , list = steps.shift() || [] + , cb_ = steps.pop() + if (typeof cb_ !== "function") throw new Error( + "No callback provided to asyncMap") + if (!list) return cb_(null, []) + if (!Array.isArray(list)) list = [list] + var n = steps.length + , data = [] // 2d array + , errState = null + , l = list.length + , a = l * n + if (!a) return cb_(null, []) + function cb (er) { + if (er && !errState) errState = er + + var argLen = arguments.length + for (var i = 1; i < argLen; i ++) if (arguments[i] !== undefined) { + data[i - 1] = (data[i - 1] || []).concat(arguments[i]) + } + // see if any new things have been added. + if (list.length > l) { + var newList = list.slice(l) + a += (list.length - l) * n + l = list.length + process.nextTick(function () { + newList.forEach(function (ar) { + steps.forEach(function (fn) { fn(ar, cb) }) + }) + }) + } + + if (--a === 0) cb_.apply(null, [errState].concat(data)) + } + // expect the supplied cb function to be called + // "n" times for each thing in the array. + list.forEach(function (ar) { + steps.forEach(function (fn) { fn(ar, cb) }) + }) +} |