floby/node-disect

Bisection helper for Javascript

node-disect

Bisection helper for javascript

Installation

npm install --save disect

Usage

Disect helps you find the first item in a list to satisfy a predicate, nothing more.

disect(0, 100, function (index) {
  return index >= 56;
})
// returns 56


// or with an array
disect([10, 20, 30], function(element, index) {
  return element > 11;
})
// returns 20;

// if you're into that...
Array.prototype.disect = function(predicate) {
  return disect(this, predicate);
}

It can also be used in an asynchronous fashion

disect(0, 100, function (index) {
  return index >= 56;
}, function (res) {
  // res === 56
})


// or with an array
disect([10, 20, 30], function(element, index, callback) {
  process.nextTick(function () {
    callback(element > 11)
  })
}, function (res) {
  // res === 20
})

Reference

disect(min, max, predicate)

Process a bisection on indexes ranging from min to max (max not included) returning the first that satisfies the predicate. This means that all indices superior to the one returned MUST validate the predicate as well. If no index validates the predicate, then max is returned

• min - Number: the minimum index against which to test
• max - Number: no indices will be tested that are equal or greater than this
• predicate - Function(index): A callback to call to test the index. Needless to say, the predicate callback should be stateless

disect(array, predicate)

Same as above, except min and max are mapped to 0 and array.length. The predicates' signature differs.

• array - Array: The array containing the elements to iterate on
• predicate - Function(element, index): A callback to call to test the element of the array at the given index

disect(min, max, predicate, callback)

Async version of the previously mention variant

• min - Number: the minimum index against which to test
• max - Number: no indices will be tested that are equal or greater than this
• predicate - Function(index, callback): A callback to call to test the index. The result of the test should be passed to the given callback
• callback - Function(result): A callback that will be called once the result is found

disect(array, predicate, callback)

You should be able to figure out what this one does

Possible evolutions

• async predicates -> async result
• accept iterator instead of range of indices

License

MIT

Copyright (c) 2013 Florent Jaby

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

node-disect's Issues

Expose an asynchronous API

The user should be able to write asynchronous predicates if the predicate function accepts a callback arguments.

Use preficate.length to use it asynchronously.