The sky is the limit

Got a little challenge parsing strings like:

Little brown="and yellow" fox=1 jumps over=lazy dog

I wanted to split it into an array with key/value pairs, so the result would be:

var res =
[ [ 'Little', undefined ],
  [ 'brown', 'and yellow' ],
  [ 'fox', '1' ],
  [ 'jumps', undefined ],
  [ 'over', 'lazy' ],
  [ 'dog', undefined ] ]

And here the regexp guy in me popped out and wanted to go for a short version. I ended up with

var text = 'Little brown="and yellow" fox=1 jumps over=lazy dog';

var res = text.match(/([^=\s]+="[^"]+")|\S+/g).map(function (p) {
    return p.match(/^([^=\s]*)(?:="?([^"]*)"?)?$/).splice(1, 2);
})

console.log(res);

The first one (/([^=\s]+=”[^”]+”)|\S+/g) splits the string into an array of param|param=value|param=”value with space”. The second one (/^([^=\s])(?:=”?([^”])”?)?$/) split that array into separate arrays which contains key,value and remove the possible double quote on the value. Since match return all the splits, I splice out the values from the new array, 1 and 2.

And there you go.

You can find the last version at GitHub

PS: This rely on that array.map() exists, which it does in #nodejs

I was coding a scheduler and needed a sorted array of the schedules, so I started to investigate the speed of different sorting variants I could use.

I created a little program (https://gist.github.com/flogvit/c9df93ab37ca4dbd2d7f) to test 4 different variants.

For the test I created an array with 100000 objects { v: num }, where num is 100000 to 1. v is the value I want to sort on. Then I did the sort 10 times for each variant, and then again running this 5 times.

The first variant was standard compare (compare):

function compare(a, b) {
  if (a.v < b.v)
    return -1;
  if (a.v > b.v)
    return 1;
  return 0;
}

sortarray.sort(compare);

The second was a value only version doing the minus variant (compareValue):

function compareValue(a, b) {
  return a.v - b.v;
}

sortarray.sort(compareValue);

Third variant is using async (async):

   async.sortBy(sortarray, function (entry, callback) {
      callback(null, entry.v);
    }, function (err, results) {
      sortarray = results;
    });

And last variant is using underscore (underscore):

sortarray = _.sortBy(sortarray, 'v');

The result where smaller is better:

compare 36.00
compareValue 36.58
underscore 50.84
async 228.48

And the full output from each run:

$ node --expose-gc sort.js
Running compare for average 30.8 ms
Running compareValue for average 38 ms
Running async for average 227 ms
Running underscore for average 51.8 ms
Running compare for average 38.8 ms
Running compareValue for average 36.6 ms
Running async for average 230.7 ms
Running underscore for average 49.5 ms
Running compare for average 37.2 ms
Running compareValue for average 35.2 ms
Running async for average 234.7 ms
Running underscore for average 52.6 ms
Running compare for average 37.4 ms
Running compareValue for average 37.1 ms
Running async for average 224.4 ms
Running underscore for average 49.4 ms
Running compare for average 35.8 ms
Running compareValue for average 36 ms
Running async for average 225.6 ms
Running underscore for average 50.9 ms