Class: SyntaxTree::YARV::Defined

Inherits:
Instruction show all
Defined in:
lib/syntax_tree/yarv/instructions.rb

Overview

### Summary

‘defined` checks if the top value of the stack is defined. If it is, it pushes its value onto the stack. Otherwise it pushes `nil`.

### Usage

~~~ruby defined?(x) ~~~

Constant Summary collapse

TYPE_NIL = 
1
TYPE_IVAR = 
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TYPE_LVAR = 
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TYPE_GVAR = 
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TYPE_CVAR = 
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TYPE_CONST = 
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TYPE_METHOD = 
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TYPE_YIELD = 
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TYPE_ZSUPER = 
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TYPE_SELF = 
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TYPE_TRUE = 
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TYPE_FALSE = 
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TYPE_ASGN = 
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TYPE_EXPR = 
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TYPE_REF = 
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TYPE_FUNC = 
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TYPE_CONST_FROM = 
17

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from Instruction

#branch_targets, #canonical, #falls_through?, #leaves?, #side_effects?

Constructor Details

#initialize(type, name, message) ⇒ Defined

Returns a new instance of Defined.



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# File 'lib/syntax_tree/yarv/instructions.rb', line 880

def initialize(type, name, message)
  @type = type
  @name = name
  @message = message
end

Instance Attribute Details

#message ⇒ Object (readonly)

Returns the value of attribute message.



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# File 'lib/syntax_tree/yarv/instructions.rb', line 878

def message
  @message
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/syntax_tree/yarv/instructions.rb', line 878

def name
  @name
end

#type ⇒ Object (readonly)

Returns the value of attribute type.



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# File 'lib/syntax_tree/yarv/instructions.rb', line 878

def type
  @type
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 939

def ==(other)
  other.is_a?(Defined) && other.type == type && other.name == name &&
    other.message == message
end

#call(vm) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 956

def call(vm)
  object = vm.pop

  result =
    case type
    when TYPE_NIL, TYPE_SELF, TYPE_TRUE, TYPE_FALSE, TYPE_ASGN, TYPE_EXPR
      message
    when TYPE_IVAR
      message if vm.frame._self.instance_variable_defined?(name)
    when TYPE_LVAR
      raise NotImplementedError, "defined TYPE_LVAR"
    when TYPE_GVAR
      message if global_variables.include?(name)
    when TYPE_CVAR
      clazz = vm.frame._self
      clazz = clazz.singleton_class unless clazz.is_a?(Module)
      message if clazz.class_variable_defined?(name)
    when TYPE_CONST
      clazz = vm.frame._self
      clazz = clazz.singleton_class unless clazz.is_a?(Module)
      message if clazz.const_defined?(name)
    when TYPE_METHOD
      raise NotImplementedError, "defined TYPE_METHOD"
    when TYPE_YIELD
      raise NotImplementedError, "defined TYPE_YIELD"
    when TYPE_ZSUPER
      raise NotImplementedError, "defined TYPE_ZSUPER"
    when TYPE_REF
      raise NotImplementedError, "defined TYPE_REF"
    when TYPE_FUNC
      message if object.respond_to?(name, true)
    when TYPE_CONST_FROM
      defined =
        vm.frame.nesting.any? { |scope| scope.const_defined?(name, true) }
      message if defined
    end

  vm.push(result)
end

#deconstruct_keys(_keys) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 935

def deconstruct_keys(_keys)
  { type: type, name: name, message: message }
end

#disasm(fmt) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 886

def disasm(fmt)
  type_name =
    case type
    when TYPE_NIL
      "nil"
    when TYPE_IVAR
      "ivar"
    when TYPE_LVAR
      "lvar"
    when TYPE_GVAR
      "gvar"
    when TYPE_CVAR
      "cvar"
    when TYPE_CONST
      "const"
    when TYPE_METHOD
      "method"
    when TYPE_YIELD
      "yield"
    when TYPE_ZSUPER
      "zsuper"
    when TYPE_SELF
      "self"
    when TYPE_TRUE
      "true"
    when TYPE_FALSE
      "false"
    when TYPE_ASGN
      "asgn"
    when TYPE_EXPR
      "expr"
    when TYPE_REF
      "ref"
    when TYPE_FUNC
      "func"
    when TYPE_CONST_FROM
      "constant-from"
    end

  fmt.instruction(
    "defined",
    [type_name, fmt.object(name), fmt.object(message)]
  )
end

#length ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 944

def length
  4
end

#pops ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 948

def pops
  1
end

#pushes ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 952

def pushes
  1
end

#to_a(_iseq) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 931

def to_a(_iseq)
  [:defined, type, name, message]
end