Method: RubyRunJs::JsArrayMethods.prototype_splice

Defined in:

lib/ruby_run_js/object_methods/js_array.rb

.prototype_splice(builtin, this, start, deleteCount, *args) ⇒ Object

# File 'lib/ruby_run_js/object_methods/js_array.rb', line 216

def prototype_splice(builtin, this, start, deleteCount, *args)
  obj, len = _to_array(this, builtin)
  relativeStart = to_integer(start)
  actualStart = relativeStart < 0 ? [0, len + relativeStart].max : [len, relativeStart].min
  actualDeleteCount = [[to_integer(deleteCount), 0].max, len - actualStart].min
  
  k = 0
  new_array = builtin.new_array
  while k < actualDeleteCount
    from = (actualStart + k).to_s
    if obj.has_property(from)
      new_array.put(k.to_s, obj.get(from))
    end
    k += 1
  end

  if args.length < actualDeleteCount
    k = actualStart
    while k < len - actualDeleteCount
      _move_item(obj, k + actualDeleteCount, k + args.length)
      k += 1
    end
  elsif args.length > actualDeleteCount
    k = len - actualDeleteCount
    while k > actualStart
      _move_item(obj, k + actualDeleteCount - 1, k + args.length - 1)
      k -= 1
    end
  end
  k = actualStart
  args.each do |item|
    obj.put(k.to_s, item, true)
    k += 1
  end
  obj.put('length', (len - actualDeleteCount + args.length).to_f, true)
  new_array
end