Class: Ruby2JS::Converter

Inherits:
Serializer show all
Defined in:
lib/ruby2js/converter.rb,
lib/ruby2js/converter/if.rb,
lib/ruby2js/converter/in.rb,
lib/ruby2js/converter/arg.rb,
lib/ruby2js/converter/def.rb,
lib/ruby2js/converter/for.rb,
lib/ruby2js/converter/nil.rb,
lib/ruby2js/converter/sym.rb,
lib/ruby2js/converter/var.rb,
lib/ruby2js/converter/args.rb,
lib/ruby2js/converter/case.rb,
lib/ruby2js/converter/cvar.rb,
lib/ruby2js/converter/defs.rb,
lib/ruby2js/converter/dstr.rb,
lib/ruby2js/converter/hash.rb,
lib/ruby2js/converter/ivar.rb,
lib/ruby2js/converter/next.rb,
lib/ruby2js/converter/self.rb,
lib/ruby2js/converter/send.rb,
lib/ruby2js/converter/xstr.rb,
lib/ruby2js/converter/array.rb,
lib/ruby2js/converter/begin.rb,
lib/ruby2js/converter/block.rb,
lib/ruby2js/converter/break.rb,
lib/ruby2js/converter/casgn.rb,
lib/ruby2js/converter/class.rb,
lib/ruby2js/converter/const.rb,
lib/ruby2js/converter/masgn.rb,
lib/ruby2js/converter/super.rb,
lib/ruby2js/converter/undef.rb,
lib/ruby2js/converter/until.rb,
lib/ruby2js/converter/vasgn.rb,
lib/ruby2js/converter/while.rb,
lib/ruby2js/converter/xnode.rb,
lib/ruby2js/converter/yield.rb,
lib/ruby2js/converter/class2.rb,
lib/ruby2js/converter/cvasgn.rb,
lib/ruby2js/converter/import.rb,
lib/ruby2js/converter/ivasgn.rb,
lib/ruby2js/converter/module.rb,
lib/ruby2js/converter/nthref.rb,
lib/ruby2js/converter/opasgn.rb,
lib/ruby2js/converter/regexp.rb,
lib/ruby2js/converter/return.rb,
lib/ruby2js/converter/taglit.rb,
lib/ruby2js/converter/boolean.rb,
lib/ruby2js/converter/defined.rb,
lib/ruby2js/converter/kwbegin.rb,
lib/ruby2js/converter/literal.rb,
lib/ruby2js/converter/logical.rb,
lib/ruby2js/converter/fileline.rb,
lib/ruby2js/converter/blockpass.rb,
lib/ruby2js/converter/prototype.rb,
lib/ruby2js/converter/untilpost.rb,
lib/ruby2js/converter/whilepost.rb

Constant Summary collapse

LOGICAL = 
:and, :not, :or
OPERATORS = 
[:[], :[]=], [:not, :!], [:**], [:*, :/, :%], [:+, :-], 
[:>>, :<<], [:&], [:^, :|], [:<=, :<, :>, :>=], [:==, :!=, :===, :"!=="],
[:and, :or]
INVERT_OP = 
{
  :<  => :>=,
  :<= => :>,
  :== => :!=,
  :!= => :==,
  :>  => :<=,
  :>= => :<,
  :=== => :'!=='
}
GROUP_OPERATORS = 
[:begin, :dstr, :dsym, :and, :or, :casgn, :if]
VASGN = 
[:cvasgn, :ivasgn, :gvasgn, :lvasgn]
EXPRESSIONS = 
[ :array, :float, :hash, :int, :lvar, :nil, :send, :attr,
:str, :sym, :dstr, :dsym, :cvar, :ivar, :zsuper, :super, :or, :and,
:block, :const, :true, :false, :xnode, :taglit, :self ]
@@handlers = 
[]

Constants inherited from Serializer

Serializer::BASE64

Instance Attribute Summary collapse

Attributes inherited from Serializer

#timestamps

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Serializer

#+, #capture, #compact, #enable_vertical_whitespace, #insert, #mtime, #output_location, #put, #put!, #puts, #reindent, #respace, #sourcemap, #sput, #to_s, #to_str, #uptodate?, #vlq, #wrap

Constructor Details

#initialize(ast, comments, vars = {}) ⇒ Converter

Returns a new instance of Converter.



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# File 'lib/ruby2js/converter.rb', line 39

def initialize( ast, comments, vars = {} )
  super()

  @ast, @comments, @vars = ast, comments, vars.dup
  @varstack = []
  @scope = ast
  @inner = nil
  @rbstack = []
  @next_token = :return

  @handlers = {}
  @@handlers.each do |name|
    @handlers[name] = method("on_#{name}")
  end

  @state = nil
  @block_this = nil
  @block_depth = nil
  @prop = nil
  @instance_method = nil
  @prototype = nil
  @class_parent = nil
  @class_name = nil
  @jsx = false

  @eslevel = :es5
  @strict = false
  @comparison = :equality
  @or = :logical
  @underscored_private = true
end

Instance Attribute Details

#ast ⇒ Object

Returns the value of attribute ast.



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# File 'lib/ruby2js/converter.rb', line 16

def ast
  @ast
end

#binding ⇒ Object

Returns the value of attribute binding.



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# File 'lib/ruby2js/converter.rb', line 37

def binding
  @binding
end

#comparison ⇒ Object

Returns the value of attribute comparison.



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# File 'lib/ruby2js/converter.rb', line 133

def comparison
  @comparison
end

#eslevel ⇒ Object

Returns the value of attribute eslevel.



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# File 'lib/ruby2js/converter.rb', line 133

def eslevel
  @eslevel
end

#ivars ⇒ Object

Returns the value of attribute ivars.



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# File 'lib/ruby2js/converter.rb', line 37

def ivars
  @ivars
end

#module_type ⇒ Object

Returns the value of attribute module_type.



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# File 'lib/ruby2js/converter.rb', line 133

def module_type
  @module_type
end

#or ⇒ Object

Returns the value of attribute or.



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# File 'lib/ruby2js/converter.rb', line 133

def or
  @or
end

#strict ⇒ Object

Returns the value of attribute strict.



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# File 'lib/ruby2js/converter.rb', line 133

def strict
  @strict
end

#underscored_private ⇒ Object

Returns the value of attribute underscored_private.



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# File 'lib/ruby2js/converter.rb', line 133

def underscored_private
  @underscored_private
end

Class Method Details

.handle(*types, &block) ⇒ Object 



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# File 'lib/ruby2js/converter.rb', line 164

def self.handle(*types, &block)
  types.each do |type| 
    define_method("on_#{type}", block)
    @@handlers << type
  end
end

Instance Method Details

#collapse_strings(node) ⇒ Object

do string concatenation when possible



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# File 'lib/ruby2js/converter/send.rb', line 357

def collapse_strings(node)
  left = node.children[0]
  return node unless left
  right = node.children[2]

  # recursively evaluate left hand side
  if \
    left.type == :send and left.children.length == 3 and
    left.children[1] == :+
  then
    left = collapse_strings(left)
  end

  # recursively evaluate right hand side
  if \
    right.type == :send and right.children.length == 3 and
    right.children[1] == :+
  then
    right = collapse_strings(right)
  end

  # if left and right are both strings, perform concatenation
  if [:dstr, :str].include? left.type and [:dstr, :str].include? right.type
    if left.type == :str and right.type == :str
      return left.updated nil,
        [left.children.first + right.children.first]
    else
      left = s(:dstr, left) if left.type == :str
      right = s(:dstr, right) if right.type == :str
      return left.updated(nil, left.children + right.children)
    end
  end

  # if left and right are unchanged, return original node; otherwise
  # return node modified to include new left and/or right hand sides.
  if left == node.children[0] and right == node.children[2]
    return node
  else
    return node.updated(nil, [left, :+, right])
  end
end

#combine_properties(body) ⇒ Object 



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# File 'lib/ruby2js/converter/begin.rb', line 34

def combine_properties(body)
  for i in 0...body.length-1
    next unless body[i] and body[i].type == :prop
    for j in i+1...body.length
      break unless body[j] and body[j].type == :prop

      if body[i].children[0] == body[j].children[0]
        # relocate property comment to first method
        [body[i], body[j]].each do |node|
          unless @comments[node].empty?
            node.children[1].values.first.each do |key, value| 
              if [:get, :set].include? key and Parser::AST::Node === value
                @comments[value] = @comments[node]
                break
              end
            end
          end
        end

        # merge properties
        merge = Hash[(body[i].children[1].to_a+body[j].children[1].to_a).
          group_by {|name, value| name.to_s}.map {|name, values|
          [name, values.map(&:last).reduce(:merge)]}]
        body[j] = s(:prop, body[j].children[0], merge)
        body[i] = nil
        break
      end
    end
  end
end

#comments(ast) ⇒ Object

extract comments that either precede or are included in the node. remove from the list this node may appear later in the tree.



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# File 'lib/ruby2js/converter.rb', line 173

def comments(ast)
  if ast.loc and ast.loc.respond_to? :expression
    expression = ast.loc.expression

    list = @comments[ast].select do |comment|
      expression.source_buffer == comment.loc.expression.source_buffer and
      comment.loc.expression.begin_pos < expression.end_pos
    end
  else
    list = @comments[ast]
  end

  @comments[ast] -= list

  list.map do |comment|
    if comment.text.start_with? '=begin'
      if comment.text.include? '*/'
        comment.text.sub(/\A=begin/, '').sub(/^=end\Z/, '').gsub(/^/, '//')
      else
        comment.text.sub(/\A=begin/, '/*').sub(/^=end\Z/, '*/')
      end
    else
      comment.text.sub(/^#/, '//') + "\n"
    end
  end
end

#conditionally_equals(left, right) ⇒ Object

determine if two trees are identical, modulo conditionalilties in other words a.b == a&.b



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# File 'lib/ruby2js/converter/logical.rb', line 89

def conditionally_equals(left, right)
  if left == right
    true
  elsif !left.respond_to?(:type) or !left or !right or left.type != :csend or right.type != :send
    false
  else
    conditionally_equals(left.children.first, right.children.first) &&
      conditionally_equals(left.children.last, right.children.last)
  end
end

#convert ⇒ Object 



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# File 'lib/ruby2js/converter.rb', line 75

def convert
  scope @ast 

  if @strict
    if @sep == '; '
      @lines.first.unshift "\"use strict\"#@sep"
    else
      @lines.unshift Line.new('"use strict";')
    end
  end
end

#es2015 ⇒ Object 



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# File 'lib/ruby2js/converter.rb', line 135

def es2015
  @eslevel >= 2015
end

#es2016 ⇒ Object 



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# File 'lib/ruby2js/converter.rb', line 139

def es2016
  @eslevel >= 2016
end

#es2017 ⇒ Object 



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# File 'lib/ruby2js/converter.rb', line 143

def es2017
  @eslevel >= 2017
end

#es2018 ⇒ Object 



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# File 'lib/ruby2js/converter.rb', line 147

def es2018
  @eslevel >= 2018
end

#es2019 ⇒ Object 



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# File 'lib/ruby2js/converter.rb', line 151

def es2019
  @eslevel >= 2019
end

#es2020 ⇒ Object 



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# File 'lib/ruby2js/converter.rb', line 155

def es2020
  @eslevel >= 2020
end

#es2021 ⇒ Object 



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# File 'lib/ruby2js/converter.rb', line 159

def es2021
  @eslevel >= 2021
end

#group(ast) ⇒ Object 



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# File 'lib/ruby2js/converter.rb', line 234

def group( ast )
  if [:dstr, :dsym].include? ast.type and es2015
    parse ast
  else
    put '('; parse ast; put ')'
  end
end

#hoist?(outer, inner, name) ⇒ Boolean

is ‘name’ referenced outside of inner scope?

Returns:

  • (Boolean) 


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# File 'lib/ruby2js/converter/vasgn.rb', line 63

def hoist?(outer, inner, name)
  outer.children.each do |var|
    next if var == inner
    return true if var == name and [:lvar, :gvar].include? outer.type
    return true if Parser::AST::Node === var and hoist?(var, inner, name)
  end
  return false
end

#jscope(ast, args = nil) ⇒ Object

handle the oddity where javascript considers there to be a scope (e.g. the body of an if statement), whereas Ruby does not.



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# File 'lib/ruby2js/converter.rb', line 117

def jscope( ast, args=nil )
  @varstack.push @vars
  @vars = args if args
  @vars = Hash[@vars.map {|key, value| [key, true]}]

  parse( ast, :statement )
ensure
  pending = @vars.select {|key, value| value == :pending}
  @vars = @varstack.pop
  @vars.merge! pending
end

#multi_assign_declarations ⇒ Object 



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# File 'lib/ruby2js/converter/vasgn.rb', line 72

def multi_assign_declarations
  undecls = []
  child = @ast
  loop do
    if [:send, :casgn].include? child.type
      subchild = child.children[2]
    else
      subchild = child.children[1]
    end

    if subchild.type == :send
      break unless subchild.children[1] =~ /=$/
    else
      break unless [:send, :cvasgn, :ivasgn, :gvasgn, :lvasgn].
        include? subchild.type
    end

    child = subchild

    if child.type == :lvasgn and not @vars.include?(child.children[0]) 
      undecls << child.children[0]
    end
  end

  unless undecls.empty?
    if es2015
      put "let "
    else
      put "var "
    end
    put "#{undecls.map(&:to_s).join(', ')}#@sep"
  end
end

#operator_index(op) ⇒ Object 



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# File 'lib/ruby2js/converter.rb', line 87

def operator_index op
  OPERATORS.index( OPERATORS.find{ |el| el.include? op } ) || -1
end

#parse(ast, state = :expression) ⇒ Object 



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# File 'lib/ruby2js/converter.rb', line 200

def parse(ast, state=:expression)
  oldstate, @state = @state, state
  oldast, @ast = @ast, ast
  return unless ast

  handler = @handlers[ast.type]

  unless handler
    raise Error.new("unknown AST type #{ ast.type }", ast)
  end

  if state == :statement and not @comments[ast].empty?
    comments(ast).each {|comment| puts comment.chomp}
  end

  handler.call(*ast.children)
ensure
  @ast = oldast
  @state = oldstate
end

#parse_all(*args) ⇒ Object 



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# File 'lib/ruby2js/converter.rb', line 221

def parse_all(*args)
  @options = (Hash === args.last) ? args.pop : {}
  sep = @options[:join].to_s
  state = @options[:state] || :expression

  index = 0
  args.each do |arg|
    put sep unless index == 0
    parse arg, state
    index += 1 unless arg == s(:begin)
  end
end

#range_to_array(node) ⇒ Object 



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# File 'lib/ruby2js/converter/send.rb', line 399

def range_to_array(node)
  start, finish = node.children
  if start.type == :int and start.children.first == 0
    # Ranges which start from 0 can be achieved with more simpler code
    if finish.type == :int
      # output cleaner code if we know the value already
      length = finish.children.first + (node.type == :irange ? 1 : 0)
    else
      # If this is variable we need to fix indexing by 1 in js
      length = "#{finish.children.last}" + (node.type == :irange ? "+1" : "")
    end

    if es2015
      return put "[...Array(#{length}).keys()]"
    else
      return put "Array.apply(null, {length: #{length}}).map(Function.call, Number)"
    end
  else
    # Use .compact because the first argument is nil with variables
    # This way the first value is always set
    start_value = start.children.compact.first
    finish_value = finish.children.compact.first
    if start.type == :int and finish.type == :int
      length = finish_value - start_value + (node.type == :irange ? 1 : 0)
    else
      length = "(#{finish_value}-#{start_value}" + (node.type == :irange ? "+1" : "") + ")"
    end

    # Avoid of using same variables in the map as used in the irange or elsewhere in this code
    # Ruby2js only allows dollar sign in beginning of variable so i$ is safe
    if @vars.include? :idx or start_value == :idx or finish_value == :idx
      index_var = 'i$'
    else
      index_var = 'idx'
    end

    if es2015
      # Use _ because it's normal convention in JS for variable which is not used at all
      if @vars.include? :_ or start_value == :_ or finish_value == :_
        blank = '_$'
      else
        blank = '_'
      end

      return put "Array.from({length: #{length}}, (#{blank}, #{index_var}) => #{index_var}+#{start_value})"
    else
      return put "Array.apply(null, {length: #{length}}).map(Function.call, Number).map(function (#{index_var}) { return #{index_var}+#{start_value} })"
    end
  end
end

#rewrite(left, right) ⇒ Object

rewrite a && a.b to a&.b



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# File 'lib/ruby2js/converter/logical.rb', line 67

def rewrite(left, right)
  if left && left.type == :and
    left = rewrite(*left.children)
  end

  if right.type != :send
    s(:and, left, right)
  elsif conditionally_equals(left, right.children.first)
    # a && a.b => a&.b
    right.updated(:csend, [left, right.children.last])
  elsif conditionally_equals(left.children.last, right.children.first)
    # a && b && b.c => a && b&.c
    left.updated(:and, [left.children.first,
      left.children.last.updated(:csend, 
      [left.children.last, right.children.last])])
  else
    s(:and, left, right)
  end
end

#s(type, *args) ⇒ Object 



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# File 'lib/ruby2js/converter.rb', line 129

def s(type, *args)
  Parser::AST::Node.new(type, args)
end

#scope(ast, args = nil) ⇒ Object

define a new scope; primarily determines what variables are visible and deals with hoisting of declarations



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# File 'lib/ruby2js/converter.rb', line 93

def scope( ast, args=nil )
  scope, @scope = @scope, ast
  inner, @inner = @inner, nil 
  mark = output_location
  @varstack.push @vars
  @vars = args if args
  @vars = Hash[@vars.map {|key, value| [key, true]}]

  parse( ast, :statement )

  # retroactively add a declaration for 'pending' variables
  vars = @vars.select {|key, value| value == :pending}.keys
  unless vars.empty?
    insert mark, "#{es2015 ? 'let' : 'var'} #{vars.join(', ')}#{@sep}"
    vars.each {|var| @vars[var] = true}
  end
ensure
  @vars = @varstack.pop
  @scope = scope
  @inner = inner
end

#timestamp(file) ⇒ Object 



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# File 'lib/ruby2js/converter.rb', line 242

def timestamp(file)
  super

  return unless file

  walk = proc do |ast|
    if ast.loc and ast.loc.expression
      filename = ast.loc.expression.source_buffer.name
      if filename and not filename.empty?
        @timestamps[filename] ||= File.mtime(filename)
      end
    end

    ast.children.each do |child|
      walk[child] if child.is_a? Parser::AST::Node
    end
  end

  walk[@ast] if @ast
end

#transform_defs(target, method, args, body) ⇒ Object 



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# File 'lib/ruby2js/converter/defs.rb', line 21

def transform_defs(target, method, args, body)
  if not @ast.is_method? or @ast.type == :defp
    node = s(:prop, target, method.to_s =>
      {enumerable: s(:true), configurable: s(:true),
      get: s(:block, s(:send, nil, :proc), args,
      s(:autoreturn, body))})
  elsif method =~ /=$/
    node = s(:prop, target, method.to_s.sub('=', '') =>
      {enumerable: s(:true), configurable: s(:true),
      set: s(:block, s(:send, nil, :proc), args,
      body)})
  else
    node = s(:send, target, "#{method}=", s(:def, nil, args, body))
  end

  @comments[node] = @comments[@ast] if @comments[@ast]

  node
end

#width=(width) ⇒ Object 



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# File 'lib/ruby2js/converter.rb', line 71

def width=(width)
  @width = width
end