Class: StyleScript::AssignNode

Inherits:
Node
  • Object
show all
Defined in:
lib/style_script/nodes.rb

Overview

Setting the value of a local variable, or the value of an object property.

Constant Summary collapse

PROTO_ASSIGN = 
/\A(\S+)\.prototype/
LEADING_DOT = 
/\A\.(prototype\.)?/

Constants inherited from Node

Node::TAB

Instance Method Summary collapse

Methods inherited from Node

#children, children, #compile, #compile_closure, #contains?, #idt, statement, statement_only, #statement_only?, top_sensitive, #top_sensitive?, #unwrap, #write

Constructor Details

#initialize(variable, value, context = nil) ⇒ AssignNode

Returns a new instance of AssignNode.



512
513
514
 
# File 'lib/style_script/nodes.rb', line 512

def initialize(variable, value, context=nil)
  @variable, @value, @context = variable, value, context
end

Instance Method Details

#compile_node(o) ⇒ Object 



516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
 
# File 'lib/style_script/nodes.rb', line 516

def compile_node(o)
  top = o.delete(:top)
  return compile_pattern_match(o) if statement?
  return compile_splice(o) if value? && @variable.splice?
  stmt        = o.delete(:as_statement)
  name        = @variable.compile(o)
  last        = value? ? @variable.last.to_s.sub(LEADING_DOT, '') : name
  proto       = name[PROTO_ASSIGN, 1]
  if @value.is_a?(CodeNode)
    @value.name  = last  if last.match(Lexer::IDENTIFIER)
    @value.proto = proto if proto
  end
  return write("#{name}: #{@value.compile(o)}") if @context == :object
  o[:scope].find(name) unless value? && @variable.properties?
  val = "#{name} = #{@value.compile(o)}"
  return write("#{idt}#{val};") if stmt
  val = "(#{val})" if !top || o[:return]
  val = "#{idt}return #{val}" if o[:return]
  write(val)
end

#compile_pattern_match(o) ⇒ Object

Implementation of recursive pattern matching, when assigning array or object literals to a value. Peeks at their properties to assign inner names. See: wiki.ecmascript.org/doku.php?id=harmony:destructuring



548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
 
# File 'lib/style_script/nodes.rb', line 548

def compile_pattern_match(o)
  val_var = o[:scope].free_variable
  assigns = ["#{idt}#{val_var} = #{@value.compile(o)};"]
  o.merge!(:top => true, :as_statement => true)
  @variable.base.objects.each_with_index do |obj, i|
    obj, i = obj.value, obj.variable.base if @variable.object?
    access_class = @variable.array? ? IndexNode : AccessorNode
    if obj.is_a?(SplatNode)
      val = LiteralNode.wrap(obj.compile_value(o, val_var, @variable.base.objects.index(obj)))
    else
      val = ValueNode.new(val_var, [access_class.new(Value.new(i.to_s))])
    end
    assigns << AssignNode.new(obj, val).compile(o)
  end
  write(assigns.join("\n"))
end

#compile_splice(o) ⇒ Object 



565
566
567
568
569
570
571
572
 
# File 'lib/style_script/nodes.rb', line 565

def compile_splice(o)
  var   = @variable.compile(o.merge(:only_first => true))
  range = @variable.properties.last.range
  plus  = range.exclusive? ? '' : ' + 1'
  from  = range.from.compile(o)
  to    = "#{range.to.compile(o)} - #{from}#{plus}"
  write("#{var}.splice.apply(#{var}, [#{from}, #{to}].concat(#{@value.compile(o)}))")
end

#statement? ⇒ Boolean

Returns:

  • (Boolean) 


541
542
543
 
# File 'lib/style_script/nodes.rb', line 541

def statement?
  value? && (@variable.array? || @variable.object?)
end

#value? ⇒ Boolean

Returns:

  • (Boolean) 


537
538
539
 
# File 'lib/style_script/nodes.rb', line 537

def value?
  @variable.is_a?(ValueNode)
end