Module: Opal::Nodes::Helpers

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

Constant Summary

RESERVED =

Reserved javascript keywords - we cannot create variables with the same name

%w[
  arguments break case catch char class const continue debugger default
  delete do else enum export extends false finally for function if import
  in instanceof let native new return static switch super this throw try
  true typeof var void while with undefined
]

Instance Method Summary collapse

Instance Method Details

#current_indent ⇒ Object 



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

def current_indent
  compiler.parser_indent
end

#empty_line ⇒ Object 



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

def empty_line
  push "\n"
end

#indent(&block) ⇒ Object 



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# File 'opal/lib/opal/nodes/helpers.rb', line 47

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

#js_falsy(sexp) ⇒ Object 



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# File 'opal/lib/opal/nodes/helpers.rb', line 74

def js_falsy(sexp)
  if sexp.type == :call
    mid = sexp[2]
    if mid == :block_given?
      scope.uses_block!
      return "#{scope.block_name} === nil"
    end
  end

  with_temp do |tmp|
    [fragment("(#{tmp} = "), expr(sexp), fragment(") === false || #{tmp} === nil")]
  end
end

#js_truthy(sexp) ⇒ Object 



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# File 'opal/lib/opal/nodes/helpers.rb', line 64

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

  with_temp do |tmp|
    [fragment("(#{tmp} = "), expr(sexp), fragment(") !== false && #{tmp} !== nil")]
  end
end

#js_truthy_optimize(sexp) ⇒ Object 



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# File 'opal/lib/opal/nodes/helpers.rb', line 88

def js_truthy_optimize(sexp)
  if sexp.type == :call
    mid = sexp[2]

    if mid == :block_given?
      expr(sexp)
    elsif Compiler::COMPARE.include? mid.to_s
      expr(sexp)
    elsif mid == :=="
      expr(sexp)
    end
  elsif [:lvar, :self].include? sexp.type
    [expr(sexp.dup), fragment(" !== false && "), expr(sexp.dup), fragment(" !== nil")]
  end
end

#line(*strs) ⇒ Object 



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

def line(*strs)
  push "\n#{current_indent}"
  push(*strs)
end

#lvar_to_js(var) ⇒ Object

Converts a ruby lvar/arg name to a js identifier. Not all ruby names are valid in javascript. A $ suffix is added to non-valid names. varibales



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

def lvar_to_js(var)
  var = "#{var}$" if RESERVED.include? var.to_s
  var.to_sym
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 39

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

#property(name) ⇒ Object 



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# File 'opal/lib/opal/nodes/helpers.rb', line 14

def property(name)
  reserved?(name) ? "['#{name}']" : ".#{name}"
end

#reserved?(name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'opal/lib/opal/nodes/helpers.rb', line 18

def reserved?(name)
  RESERVED.include? name
end

#variable(name) ⇒ Object 



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# File 'opal/lib/opal/nodes/helpers.rb', line 22

def variable(name)
  reserved?(name.to_s) ? "#{name}$" : name
end