Class: Opal::Nodes::MlhsArgNode

Inherits:

Base

• Object
• Base
• Opal::Nodes::MlhsArgNode

Defined in:

opal/lib/opal/nodes/args/mlhsarg.rb

Overview

A node responsible for extracting a single MLHS argument

MLHS argument is the left hand side of a multiple assignment (Multiple Left Hand Side)

def m((a, b)) def m((a, *b))

MLHS can include simple arguments (see NormargNode) and rest arguments (see RestargNode)

Instance Attribute Summary

Attributes inherited from Base

#compiler, #type

Instance Method Summary

• #compile ⇒ Object
• #inline_args ⇒ Object
• #mlhs_name ⇒ Object

Methods inherited from Base

#add_gvar, #add_ivar, #add_local, #add_temp, #children, children, #class_variable_owner, #closest_module_node, #comments, #compile_to_fragments, #error, #expr, #expr?, #expr_or_nil, #fragment, handle, handlers, #has_rescue_else?, #helper, #in_ensure, #in_ensure?, #in_while?, #initialize, #process, #push, #recv, #recv?, #s, #scope, #stmt, #stmt?, truthy_optimize?, #unshift, #while_loop, #with_temp, #wrap

Methods included from Helpers

#conditional_send, #current_indent, #empty_line, #indent, #js_falsy, #js_truthy, #js_truthy_optimize, #line, #mid_to_jsid, #property, #valid_name?

Constructor Details

This class inherits a constructor from Opal::Nodes::Base

Instance Method Details

#compile ⇒ Object

# File 'opal/lib/opal/nodes/args/mlhsarg.rb', line 21

def compile
  args_sexp = s(:post_args, *children)

  if @sexp.meta[:post]
    # In this case source is an item in the current scope.working_arguments
    # First we should extract mlhs as a simple argument
    mlhs_sexp = s(:arg, mlhs_name)
    mlhs_sexp.meta[:post] = true
    scope.with_inline_args([]) do
      push process(mlhs_sexp)
    end
    var_name = args_sexp.meta[:js_source] = mlhs_name
  else
    # Otherwise we already have it in our scope.working_arguments
    # (of course, in this case scope.working_arguments = 'arguments')
    var_name = args_sexp.meta[:js_source] = scope.mlhs_mapping[@sexp]
  end

  line "if (#{var_name} == null) {"
  line "  #{var_name} = nil;"
  line "}"

  line "#{var_name} = Opal.to_ary(#{var_name});"

  scope.with_inline_args([]) do
    scope.in_mlhs do
      push process(args_sexp)
    end
  end
end

#inline_args ⇒ Object

# File 'opal/lib/opal/nodes/args/mlhsarg.rb', line 73

def inline_args
  @inline_args ||= children.take_while { |arg| arg.type != :restarg && arg.type != :optarg }
end

#mlhs_name ⇒ Object

# File 'opal/lib/opal/nodes/args/mlhsarg.rb', line 52

def mlhs_name
  @mlhs_name ||= begin
    if @sexp.meta[:post]
      result = ["$mlhs_of"]

      children.each do |child|
        case child.type
        when :arg
          result << child.children[0]
        when :mlhs
          result << 'mlhs'
        end
      end

      result.join("_")
    else
      @sexp.children[0].to_s
    end
  end
end