Class: Opal::Rewriters::DeduplicateArgName

Inherits:

Base

Object
Parser::AST::Processor
Base
Opal::Rewriters::DeduplicateArgName

Defined in:: opal/lib/opal/rewriters/deduplicate_arg_name.rb

Overview

Ruby allows for args with the same name, if the arg starts with a '', like: def funny_method_name(, ) puts _ end but JavaScript in strict mode does not allow for args with the same name Ruby assigns the value of the first arg given funny_method_name(1, 2) => 1 leave the first appearance as it is and rename the other ones compiler result: function $$funny_method_name(, __2ドル)

Constant Summary

Constants inherited from Base

Base::DUMMY_LOCATION

Instance Attribute Summary

Attributes inherited from Base

#current_node

Methods inherited from Base

#append_to_body , #begin_with_stmts , #dynamic! , #error , #on_top , #prepend_to_body , #process , s , #s , #stmts_of

Instance Method Details

#on_args(node) ⇒ `Object`

# File 'opal/lib/opal/rewriters/deduplicate_arg_name.rb', line 16
def on_args(node)
 @arg_name_count = Hash.new(0)
 children = node.children.map do |arg|
 rename_arg(arg)
 end
 super(node.updated(nil, children))
end

#rename_arg(arg) ⇒ `Object`

# File 'opal/lib/opal/rewriters/deduplicate_arg_name.rb', line 26
def rename_arg(arg)
 case arg.type
 when :arg, :restarg, :kwarg, :kwrestarg, :blockarg
 name = arg.children[0]
 name ? arg.updated(nil, [unique_name(name)]) : arg
 when :optarg, :kwoptarg
 name, value = arg.children
 arg.updated(nil, [unique_name(name), value])
 when :mlhs
 new_children = arg.children.map { |child| rename_arg(child) }
 arg.updated(nil, new_children)
 else
 arg
 end
end

#unique_name(name) ⇒ `Object`

# File 'opal/lib/opal/rewriters/deduplicate_arg_name.rb', line 42
def unique_name(name)
 count = (@arg_name_count[name] += 1)
 count > 1 ? :"#{name}_$#{count}" : name
end