Module: Ruby2JS::Filter::Underscore

Includes:
SEXP
Defined in:
lib/ruby2js/filter/underscore.rb

Instance Method Summary collapse

Methods included from SEXP

#S, #s

Instance Method Details

#on_block(node) ⇒ Object 



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# File 'lib/ruby2js/filter/underscore.rb', line 112

def on_block(node)
  call = node.children.first
  method = call.children[1]
  return super if excluded?(method)

  if [:sort_by, :group_by, :index_by, :count_by].include? method
    # input: a.sort_by {}
    # output: _.sortBy {return expression}
    method = method.to_s.sub(/\_by$/,'By').to_sym
    process S(:block, s(:send, s(:lvar, :_), method,
      call.children.first), node.children[1],
      s(:autoreturn, node.children[2]))
  elsif [:find, :reject].include? method
    if call.children.length == 2
      # input: a.find {|item| item > 0}
      # output: _.find(a) {|item| return item > 0}
      process S(:block, s(:send, s(:lvar, :_), method,
        call.children.first), node.children[1],
        s(:autoreturn, node.children[2]))
    else
      super
    end

  elsif method == :times and call.children.length == 2
    # input: 5.times {|i| console.log i}
    # output: _.find(5) {|i| console.log(i)}
    process S(:block, s(:send, s(:lvar, :_), method,
      call.children.first), node.children[1], node.children[2])

  elsif method == :reduce
    if call.children.length == 2
      # input: a.reduce {|memo, item| memo+item}
      # output: _.reduce(_.rest(a),
      #                  proc {|memo, item| return memo+item},
      #                  a[0])
      process S(:call, s(:lvar, :_), :reduce,
        s(:send, s(:lvar, :_), :rest, call.children.first),
        s(:block, s(:send, nil, :proc),
          node.children[1], s(:autoreturn, node.children[2])),
          s(:send, call.children.first, :[], s(:int, 0)))
    elsif call.children.length == 3
      # input: a.reduce(n) {|memo, item| memo+item}
      # output: _.reduce(a, proc {|memo, item| return memo+item}, n)
      process S(:call, s(:lvar, :_), :reduce, call.children.first,
        s(:block, s(:send, nil, :proc),
          node.children[1], s(:autoreturn, node.children[2])),
          call.children[2])
    end

  elsif [:map!, :reject!, :select!, :sort_by!].include? method
    # input: a.map! {expression}
    # output: a.splice(0, a.length, *a.map {expression})
    method = :"#{method.to_s[0..-2]}"
    target = call.children.first
    process S(:call, target, :splice, s(:splat, s(:send, s(:array,
      s(:int, 0), s(:attr, target, :length)), :concat,
      s(:block, s(:send, target, method, *call.children[2..-1]),
      *node.children[1..-1]))))

  else
    super
  end
end

#on_erange(node) ⇒ Object 



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# File 'lib/ruby2js/filter/underscore.rb', line 176

def on_erange(node)
  process s(:send, s(:lvar, :_), :range, *node.children)
end

#on_for(node) ⇒ Object 



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# File 'lib/ruby2js/filter/underscore.rb', line 190

def on_for(node)
  # pass through irange, erange unprocessed
  return super unless [:irange, :erange].include? node.children[1].type
  s(:for, process(node.children[0]), s(node.children[1].type,
    *process_all(node.children[1].children)), process(node.children[2]))
end

#on_irange(node) ⇒ Object 



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# File 'lib/ruby2js/filter/underscore.rb', line 180

def on_irange(node)
  if node.children.last.type == :int
    process S(:call, s(:lvar, :_), :range, node.children.first,
      s(:int, node.children.last.children.last+1))
  else
    process S(:call, s(:lvar, :_), :range, node.children.first,
      s(:send, node.children.last, :+, s(:int, 1)))
  end
end

#on_send(node) ⇒ Object 



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# File 'lib/ruby2js/filter/underscore.rb', line 10

def on_send(node)
  return super if node.children.first and node.children.first.children.last == :_

  method = node.children[1]
  return super if excluded?(method)

  if [:clone, :shuffle, :size, :compact, :flatten, :invert, :values,
    :uniq].include? method
    if node.is_method?  and node.children.length == 2
      process S(:send, s(:lvar, :_), method, node.children[0])
    else
      super
    end
  elsif [:take, :drop].include? method and node.is_method?
    process S(:send, s(:lvar, :_), method, node.children[0], node.children[2])
  elsif method == :each_slice and node.is_method?
    process S(:send, s(:lvar, :_), :chunk, node.children[0], node.children[2])
  elsif [:min, :max].include? method and node.children.length == 2
    process S(:send, s(:lvar, :_), method, node.children[0])
  elsif method == :sample and  node.children.length <= 3
    process S(:send, s(:lvar, :_), :sample, node.children[0],
      *node.children[2..-1])
  elsif method == :has_key? and  node.children.length == 3
    process S(:send, s(:lvar, :_), :has, node.children[0],
      node.children[2])
  elsif method == :sort and  node.children.length == 2
    if node.is_method?
      process S(:send, s(:lvar, :_), :sortBy, node.children[0],
        s(:attr, s(:lvar, :_), :identity))
    else
      super
    end
  elsif method == :map
    if node.children.length == 3 and node.children[2].type == :block_pass
      process S(:send, s(:lvar, :_), :pluck, node.children[0],
        node.children[2].children.first)
    else
      super
    end
  elsif method == :merge and node.children.length >= 3
    process S(:send, s(:lvar, :_), :extend, s(:hash), node.children[0],
      *node.children[2..-1])
  elsif method == :merge! and node.children.length >= 3
    process S(:send, s(:lvar, :_), :extend, node.children[0],
      *node.children[2..-1])
  elsif method == :zip and node.children.length >= 3
    process S(:send, s(:lvar, :_), :zip, node.children[0],
      *node.children[2..-1])
  elsif method == :invoke
    if node.children.length >= 3 and node.children.last.type==:block_pass
      process S(:send, s(:lvar, :_), :invoke, node.children[0],
        node.children.last.children.first,
        *node.children[2..-2])
    else
      super
    end
  elsif [:where, :find_by].include? method
    method = (method == :where ? :where : :findWhere)
    process S(:send, s(:lvar, :_), method, node.children[0],
      *node.children[2..-1])
  elsif method == :reduce
    if node.children.length == 3 and node.children[2].type == :sym
      # input: a.reduce(:+)
      # output: _.reduce(_.rest(a),
      #                  proc {|memo, item| return memo+item},
      #                  a[0])
      process S(:send, s(:lvar, :_), :reduce,
        s(:send, s(:lvar, :_), :rest, node.children.first),
        s(:block, s(:send, nil, :proc),
          s(:args, s(:arg, :memo), s(:arg, :item)),
          s(:autoreturn, s(:send, s(:lvar, :memo),
            node.children[2].children.first, s(:lvar, :item)))),
          s(:send, node.children.first, :[], s(:int, 0)))
    elsif node.children.last.type == :block_pass
      on_send node.updated(nil, [*node.children[0..1],
        node.children[2].children.first])
    elsif node.children.length == 4 and node.children[3].type == :sym
      # input: a.reduce(n, :+)
      # output: _.reduce(a, proc {|memo, item| return memo+item}, n)
      process S(:send, s(:lvar, :_), :reduce, node.children.first,
        s(:block, s(:send, nil, :proc),
          s(:args, s(:arg, :memo), s(:arg, :item)),
          s(:autoreturn, s(:send, s(:lvar, :memo),
          node.children[3].children.first, s(:lvar, :item)))),
          node.children[2])
    else
      super
    end

  elsif [:compact!, :flatten!, :shuffle!, :uniq!].
    include? method and node.is_method?
    # input: a.compact!
    # output: a.splice(0, a.length, *a.compact)
    target = node.children.first
    process S(:send, target, :splice, s(:int, 0),
      s(:attr, target, :length), s(:splat, s(:send, target,
      :"#{method.to_s[0..-2]}", *node.children[2..-1])))
  else
    super
  end
end