Class: Minjs::ECMA262::StIf

Inherits:
Statement show all
Defined in:
lib/minjs/ecma262/statement.rb

Overview

Base class of ECMA262 IfStatement element.

See Also:

Instance Attribute Summary collapse

Attributes inherited from Base

#parent

Instance Method Summary collapse

Methods inherited from Statement

#empty?, #priority

Methods inherited from Base

#add_remove_paren, #concat

Constructor Details

#initialize(cond, then_st, else_st) ⇒ StIf

Returns a new instance of StIf.



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# File 'lib/minjs/ecma262/statement.rb', line 354

def initialize(cond, then_st, else_st)
  @cond = cond
  @then_st = then_st
  @else_st = else_st
end

Instance Attribute Details

#cond ⇒ Object (readonly)

Returns the value of attribute cond.



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# File 'lib/minjs/ecma262/statement.rb', line 352

def cond
  @cond
end

#else_st ⇒ Object (readonly)

Returns the value of attribute else_st.



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# File 'lib/minjs/ecma262/statement.rb', line 352

def else_st
  @else_st
end

#then_st ⇒ Object (readonly)

Returns the value of attribute then_st.



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# File 'lib/minjs/ecma262/statement.rb', line 352

def then_st
  @then_st
end

Instance Method Details

#==(obj) ⇒ Object

compare object



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# File 'lib/minjs/ecma262/statement.rb', line 389

def ==(obj)
  self.class == obj.class and
    @cond == obj.cond and
    @then_st == obj.then_st and
    @else_st == obj.else_st
end

#add_paren ⇒ Object

add parenthesis if need



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# File 'lib/minjs/ecma262/statement.rb', line 486

def add_paren
  self
end

#deep_dup ⇒ Object

duplicate object

See Also:



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# File 'lib/minjs/ecma262/statement.rb', line 384

def deep_dup
  self.class.new(@cond.deep_dup, @then_st.deep_dup, @else_st ? @else_st.deep_dup : nil)
end

#remove_empty_statement ⇒ Object

Removes empty statement in this then-clause or else-clause



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# File 'lib/minjs/ecma262/statement.rb', line 491

def remove_empty_statement
  if @then_st.kind_of? StBlock
    @then_st.remove_empty_statement
  end
  if @else_st.kind_of? StBlock
    @else_st.remove_empty_statement
  end
end

#remove_paren ⇒ Object

remove parenthesis if possible



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# File 'lib/minjs/ecma262/statement.rb', line 478

def remove_paren
  if @cond.kind_of? ExpParen
    @cond = @cond.val
  end
  self
end

#replace(from, to) ⇒ Object

Replaces children object.

See Also:



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# File 'lib/minjs/ecma262/statement.rb', line 362

def replace(from, to)
  if from .eql? @cond
    @cond = to
  elsif from .eql? @then_st
    @then_st = to
  elsif from .eql? @else_st
    @else_st = to
  end
end

#to_exp(options = {}) ⇒ Object

Converts statement to expression and returns it.



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# File 'lib/minjs/ecma262/statement.rb', line 448

def to_exp(options = {})
  cond = @cond.deep_dup
  if !@else_st
    then_exp = @then_st.to_exp(options)
    if(options[:cond])
      if cond.kind_of? ExpLogicalNot
        add_remove_paren ExpCond.new(cond.val, ECMA262Numeric.new(0), then_exp)
      else
        add_remove_paren ExpCond.new(cond, then_exp, ECMA262Numeric.new(0))
      end
    else
      if cond.kind_of? ExpLogicalNot
        add_remove_paren ExpLogicalOr.new(cond.val, then_exp)
      else
        add_remove_paren ExpLogicalAnd.new(cond, then_exp)
      end
    end
  else
    then_exp = @then_st.to_exp(options)
    else_exp = @else_st.to_exp(options)

    if cond.kind_of? ExpLogicalNot
      add_remove_paren ExpCond.new(cond.val, else_exp, then_exp)
    else
      add_remove_paren ExpCond.new(cond, then_exp, else_exp)
    end
  end
end

#to_exp? ⇒ Boolean

true if statement can convert to expression

Returns:



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# File 'lib/minjs/ecma262/statement.rb', line 437

def to_exp?
  if !@else_st
    return false if @then_st.to_exp? == false
  else
    return false if @then_st.to_exp? == false
    return false if @else_st.to_exp? == false
  end
  return true
end

#to_js(options = {}) ⇒ Object

Returns a ECMAScript string containg the representation of element.

See Also:



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# File 'lib/minjs/ecma262/statement.rb', line 398

def to_js(options = {})
  if @else_st
    concat options, :if, "(", @cond, ")", @then_st, :else, @else_st
  else
    concat options, :if, "(", @cond, ")", @then_st
  end
end

#to_return ⇒ Object

Converts block to ‘return statement’ and returns it



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# File 'lib/minjs/ecma262/statement.rb', line 416

def to_return
  then_exp = then_st.exp;
  if @else_st
    else_exp = else_st.exp;
  end

  if then_exp.nil?
    then_exp = ExpVoid.new(ECMA262Numeric.new(0))
  end
  if @else_st and else_exp.nil?
    else_exp = ExpVoid.new(ECMA262Numeric.new(0))
  end
  if @else_st
    ret = add_remove_paren StReturn.new(ExpCond.new(@cond, then_exp, else_exp))
  else
    ret = add_remove_paren StReturn.new(ExpLogicalAnd.new(@cond, then_exp))
  end
  ret
end

#to_return? ⇒ Boolean

return true if statement can convert to return statement.

Returns:



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# File 'lib/minjs/ecma262/statement.rb', line 407

def to_return?
  if !@else_st
    return false
  else
    return true if @then_st.class == StReturn and @else_st.class == StReturn
  end
end

#traverse(parent) {|parent, _self| ... } ⇒ Object

Traverses this children and itself with given block.

Yields:

Yield Parameters:



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# File 'lib/minjs/ecma262/statement.rb', line 373

def traverse(parent, &block)
  @cond.traverse(self, &block)
  @then_st.traverse(self, &block)
  if @else_st
    @else_st.traverse(self, &block)
  end
  yield parent, self
end