Underscore

The Underscore filter maps relevant Ruby methods to their Underscore.js library equivalents.

List of Transformations

• .clone() _.clone()
• .compact() _.compact()
• .count_by {} _.countBy {}
• .find {} _.find {}
• .find_by() _.findWhere()
• .flatten() _.flatten()
• .group_by {} _.groupBy {}
• .has_key?() _.has()
• .index_by {} _.indexBy {}
• .invert() _.invert()
• .invoke(&:n) _.invoke(, :n)
• .map(&:n) _.pluck(, :n)
• .merge!() _.extend()
• .merge() _.extend({}, )
• .reduce {} _.reduce {}
• .reduce() _.reduce()
• .reject {} _.reject {}
• .sample() _.sample()
• .select {} _.select {}
• .shuffle() _.shuffle()
• .size() _.size()
• .sort() _.sort_by(, _.identity)
• .sort_by {} _.sortBy {}
• .times {} _.times {}
• .values() _.values()
• .where() _.where()
• .zip() _.zip()
• (n...m) _.range(n, m)
• (n..m) _.range(n, m+1)
• n.take(m) _.take(n, m)
• n.drop(m) _.drop(n, m)
• .min _.min()
• .max _.max()
• n.each_slice(m) _.chunk(n, m)

Additional Features

• .compact!, .flatten!, shuffle!, reject!, sort_by!, and .uniq become equivalent .splice(0, .length, *.method()) statements
• for the following methods, if the block consists entirely of a simple expression (or ends with one), a return is added prior to the expression: reduce, sort_by, group_by, index_by, count_by, find, select, reject.
• is_a? and kind_of? map to Object.prototype.toString.call() === "[object #{type}]" for the following types: Arguments, Boolean, Date, Error, Function, Number, Object, RegExp, String; and maps Ruby names to JavaScript equivalents for Exception, Float, Hash, Proc, and Regexp. Additionally, is_a? and kind_of? map to Array.isArray() for Array`.