Tacit

Overview

Tacit/point-free function chains. Like chains in underscore or lo-dash, but with cleaner syntax. To compare:

Underscore:

var countUnique = function(array) {
  return _.chain(array)
    .uniq()
    .size()
    .value();
}

Lo-dash

var countUnique = function(array) {
  return _(array)
    .uniq()
    .size()
    .value();
}

Tacit:

var countUnique = _()
  .uniq()
  .size();

Usage

Install:

npm install tacit

Basic usage:

var tacit = require('tacit');
var _ = require('underscore');
 
var _t = tacit(_);
 
var countUnique = _t()
  .flatten()
  .uniq()
  .size();
 
var size = countUnique([[1,2],[2,3]]);
 
// prints 3
console.log(size);

If no functions are added to the chain, then the tacit function is just the identity function, i.e.:

var _t = tacit(_);
 
var value = _t('Hello World');
 
// prints 'Hello World'
console.log(value);

To support arguments that aren't in the last position, either set the default position:

var _t = tacit(_, 0);
 
var countUnique = _t()
  .map(String.length)
  .sortBy(Math.sin);
 
 
var sizes = countUnique(['the', 'quick', 'jumped', 'over', 'a', 'of]);
 
// prints [5, 4, 6, 3, 1, 2]
console.log(sizes);

A value of -1 for the default position means: "insert in the last position". If a value isn't specified for the default position, -1 is assumed.

Another option is to use the special $ operator:

var $ = tacit.$;
var _t = tacit(_);
 
var countUnique = _t()
  .map($, String.length)
  .sortBy($. Math.sin);

This overrides the default position on a function-by-function basis.