Module: Opal::Nodes::Helpers

Included in:
Base
Defined in:
opal/lib/opal/nodes/helpers.rb

Instance Method Summary collapse

Instance Method Details

#conditional_send(recvr) {|receiver_temp| ... } ⇒ Object

Usefule for safe-operator calls: foo&.bar / foo&.bar ||= baz / ...

Parameters:

  • recvr (sexp_pushable) —

    The receiver of the call that will be stored in a temporary variable

Yields:

  • (receiver_temp) 


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# File 'opal/lib/opal/nodes/helpers.rb', line 126

def conditional_send(recvr)
  # temporary variable that stores method receiver
  receiver_temp = scope.new_temp
  push "#{receiver_temp} = ", recvr

  # execute the sexp only if the receiver isn't nil
  push ", (#{receiver_temp} === nil || #{receiver_temp} == null) ? nil : "
  yield receiver_temp
  wrap '(', ')'
end

#current_indent ⇒ Object 



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# File 'opal/lib/opal/nodes/helpers.rb', line 33

def current_indent
  compiler.parser_indent
end

#empty_line ⇒ Object 



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# File 'opal/lib/opal/nodes/helpers.rb', line 42

def empty_line
  push fragment("\n", loc: false)
end

#indent(&block) ⇒ Object 



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# File 'opal/lib/opal/nodes/helpers.rb', line 29

def indent(&block)
  compiler.indent(&block)
end

#js_truthy(sexp) ⇒ Object 



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# File 'opal/lib/opal/nodes/helpers.rb', line 46

def js_truthy(sexp)
  if optimize = js_truthy_optimize(sexp)
    return optimize
  end

  helper :truthy
  [fragment('$truthy('), expr(sexp), fragment(')')]
end

#js_truthy_optimize(sexp) ⇒ Object 



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# File 'opal/lib/opal/nodes/helpers.rb', line 55

def js_truthy_optimize(sexp)
  case sexp.type
  when :send
    receiver, mid, *args = *sexp
    receiver_handler_class = receiver && compiler.handlers[receiver.type]

    # Only operator calls on the truthy_optimize? node classes should be optimized.
    # Monkey patch method calls might return 'self'/aka a bridged instance and need
    # the nil check - see discussion at https://github.com/opal/opal/pull/1097
    allow_optimization_on_type = Compiler::COMPARE.include?(mid.to_s) &&
                                 receiver_handler_class &&
                                 receiver_handler_class.truthy_optimize?

    if allow_optimization_on_type ||
       mid == :block_given?
      expr(sexp)
    elsif args.count == 1
      case mid
      when :==
        helper :eqeq
        compiler.method_calls << mid
        [fragment('$eqeq('), expr(receiver), fragment(', '), expr(args.first), fragment(')')]
      when :===
        helper :eqeqeq
        compiler.method_calls << mid
        [fragment('$eqeqeq('), expr(receiver), fragment(', '), expr(args.first), fragment(')')]
      when :!=
        helper :neqeq
        compiler.method_calls << mid
        [fragment('$neqeq('), expr(receiver), fragment(', '), expr(args.first), fragment(')')]
      end
    elsif args.count == 0
      case mid
      when :!
        helper :not
        compiler.method_calls << mid
        [fragment('$not('), expr(receiver), fragment(')')]
      end
    end
  when :begin
    if sexp.children.count == 1
      js_truthy_optimize(sexp.children.first)
    end
  when :if
    _test, true_body, false_body = *sexp
    if true_body == s(:true)
      # Ensure we recurse the js_truthy call on the `false_body` of the if `expr`.
      # This transforms an expression like:
      #
      # $truthy($truthy(a) || b)
      #
      # Into:
      #
      # $truthy(a) || $truthy(b)
      sexp.meta[:do_js_truthy_on_false_body] = true
      expr(sexp)
    elsif false_body == s(:false)
      sexp.meta[:do_js_truthy_on_true_body] = true
      expr(sexp)
    end
  end
end

#line(*strs) ⇒ Object 



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# File 'opal/lib/opal/nodes/helpers.rb', line 37

def line(*strs)
  push fragment("\n#{current_indent}", loc: false)
  push(*strs)
end

#mid_to_jsid(mid) ⇒ Object

Converts a ruby method name into its javascript equivalent for a method/function call. All ruby method names get prefixed with a '$', and if the name is a valid javascript identifier, it will have a '.' prefix (for dot-calling), otherwise it will be wrapped in brackets to use reference notation calling.



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

def mid_to_jsid(mid)
  if %r{\=|\+|\-|\*|\/|\!|\?|<|\>|\&|\||\^|\%|\~|\[|`} =~ mid.to_s
    "['$#{mid}']"
  else
    '.$' + mid
  end
end

#property(name) ⇒ Object 



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# File 'opal/lib/opal/nodes/helpers.rb', line 8

def property(name)
  valid_name?(name) ? ".#{name}" : "[#{name.inspect}]"
end

#valid_name?(name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'opal/lib/opal/nodes/helpers.rb', line 12

def valid_name?(name)
  Opal::Rewriters::JsReservedWords.valid_name?(name)
end