Class: Opal::Nodes::PostArgsNode

Inherits:
Base
  • Object
show all
Defined in:
opal/lib/opal/nodes/args/post_args.rb

Overview

Node responsible for extracting post-splat args

  1. There can be some arguments after the splat, this is why this node exist. In this case if: a. JS arguments length > args sexp length - then our splat has some items and we know how many of them should come to splat b. JS arguments length < args sexp length - then our splat is blank

  2. Super important: a) optional arg always goes BEFORE the rest arg b) optional args always appear in the sequence (i.e. you can't have def m(a=1,b,c=1)) c) precedence order: 1. required arg (norm arg, mlhs arg) 2. optional argument (optarg) 3. splat/rest argument (restarg) These statements simplify everything, keep them in mind.

  3. post_args here always have the same structure:

    1. list of required arguments (only for mlhs, can be blank)
    2. list of optargs (only for post-args, can be blank)
    3. restarg (for both mlhs/post-args, can be nil)
    4. list of required args (for both mlhs/post-args, can be blank)

Instance Attribute Summary collapse

Attributes inherited from Base

#compiler, #type

Instance Method Summary collapse

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?, #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

#initialize ⇒ PostArgsNode

Returns a new instance of PostArgsNode



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

def initialize(*)
  super

  @kwargs = []
  @required_left_args = []
  @optargs = []
  @restarg = nil
  @required_right_args = []
end

Instance Attribute Details

#kwargs ⇒ Object (readonly)

kwargs contains the list of all post-kw* arguments all of them can be processed in the first oder



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# File 'opal/lib/opal/nodes/args/post_args.rb', line 32

def kwargs
  @kwargs
end

#optargs ⇒ Object (readonly)

optargs contains the list of optarg arguments all of them must be populated depending on the "arguments.length" if we have enough arguments - we fill them, if not - we populate it with its default value For post-args: can be provided from def m(a=1, *b) post-args = [(:optarg, :a, (:int, 1)), (:restarg, :b)] optargs = [(:optarg, :a, (:int, 1))] For mlhs: always blank



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# File 'opal/lib/opal/nodes/args/post_args.rb', line 51

def optargs
  @optargs
end

#required_left_args ⇒ Object (readonly)

required_left_args contains the list of required post args like normarg or mlhs For post-args: always blank (post args always start with optarg/restarg) For mlhs: can be provided from mlhs = (a, b, c) required_left_args = [(:arg, :a), (:arg, :b)]



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# File 'opal/lib/opal/nodes/args/post_args.rb', line 40

def required_left_args
  @required_left_args
end

#required_right_args ⇒ Object (readonly)

required_right_args contains the list of required post args like normarg and mlhs arg For post-args: can be provided from def m(a=1,*b,c) post-args = [(:optarg, :a, (:int, 1)), (:restarg, :b), (:arg, :c)] required_right_args = [(:arg, :c)] For mlhs: can be provided from (*a, b) required_right_args = [(:arg, :b)]



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# File 'opal/lib/opal/nodes/args/post_args.rb', line 71

def required_right_args
  @required_right_args
end

#restarg ⇒ Object (readonly)

returns a restarg sexp if we have enough "arguments" - we fill it if not - we populate it with "[]" For post-args: can be provided from def m(a=1, *b) post-args = [(:optarg, :a, (:int, 1)), (:restarg, :b)] restarg (:restarg, :b)



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# File 'opal/lib/opal/nodes/args/post_args.rb', line 60

def restarg
  @restarg
end

Instance Method Details

#compile ⇒ Object 



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# File 'opal/lib/opal/nodes/args/post_args.rb', line 108

def compile
  return if children.empty?

  old_working_arguments = scope.working_arguments

  if @sexp.meta[:js_source]
    js_source = @sexp.meta[:js_source]
    scope.working_arguments = "#{js_source}_args"
  else
    js_source = "arguments"
    scope.working_arguments = "$post_args"
  end

  add_temp "#{scope.working_arguments}"
  line "#{scope.working_arguments} = Opal.slice.call(#{js_source}, #{scope.inline_args.size}, #{js_source}.length);"

  extract_arguments

  push process(kwargs_sexp)

  required_left_args.each do |arg|
    compile_required_arg(arg)
  end

  optargs.each do |optarg|
    compile_optarg(optarg)
  end

  compile_restarg

  required_right_args.each do |arg|
    compile_required_arg(arg)
  end

  scope.working_arguments = old_working_arguments
end

#compile_optarg(optarg) ⇒ Object 



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# File 'opal/lib/opal/nodes/args/post_args.rb', line 145

def compile_optarg(optarg)
  var_name, _ = *optarg
  add_temp var_name

  line "if (#{required_right_args.size} < #{scope.working_arguments}.length) {"
  indent do
    line "#{var_name} = #{scope.working_arguments}.splice(0,1)[0];"
  end
  line "}"
  push process(optarg)
end

#compile_required_arg(arg) ⇒ Object 



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# File 'opal/lib/opal/nodes/args/post_args.rb', line 157

def compile_required_arg(arg)
  push process(arg)
end

#compile_restarg ⇒ Object 



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# File 'opal/lib/opal/nodes/args/post_args.rb', line 161

def compile_restarg
  return unless restarg

  line "if (#{required_right_args.size} < #{scope.working_arguments}.length) {"
    indent do
      # there are some items coming to the splat, extracting them
      extract_restarg
    end
  line "} else {"
    indent do
      # splat is empty
      extract_blank_restarg
    end
  line "}"
end

#extract_arguments ⇒ Object 



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# File 'opal/lib/opal/nodes/args/post_args.rb', line 83

def extract_arguments
  found_opt_or_rest = false

  children.each do |arg|
    arg.meta[:post] = true

    case arg.type
    when :kwarg, :kwoptarg, :kwrestarg
      @kwargs << arg
    when :restarg
      @restarg = arg
      found_opt_or_rest = true
    when :optarg
      @optargs << arg
      found_opt_or_rest = true
    when :arg, :mlhs
      if found_opt_or_rest
        @required_right_args << arg
      else
        @required_left_args << arg
      end
    end
  end
end

#extract_blank_restarg ⇒ Object 



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# File 'opal/lib/opal/nodes/args/post_args.rb', line 188

def extract_blank_restarg
  var_name, _ = *restarg
  if var_name
    add_temp var_name
    line "#{var_name} = [];"
  end
end

#extract_restarg ⇒ Object 



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# File 'opal/lib/opal/nodes/args/post_args.rb', line 177

def extract_restarg
  extract_code = "#{scope.working_arguments}.splice(0, #{scope.working_arguments}.length - #{required_right_args.size});"
  var_name, _ = *restarg
  if var_name
    add_temp var_name
    line "#{var_name} = #{extract_code}"
  else
    line extract_code
  end
end

#kwargs_sexp ⇒ Object 



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# File 'opal/lib/opal/nodes/args/post_args.rb', line 196

def kwargs_sexp
  s(:post_kwargs, *kwargs)
end