Class: SyntaxTree::YARV::CheckType

Inherits:

Instruction

• Object
• Instruction
• SyntaxTree::YARV::CheckType

Defined in:

lib/syntax_tree/yarv/instructions.rb

Overview

### Summary

‘checktype` checks if the value on top of the stack is of a certain type. The type is the only argument. It pops the value off the stack and pushes a boolean onto the stack indicating whether or not the value is of the given type.

### Usage

~~~ruby foo in [bar] ~~~

Constant Summary

TYPE_OBJECT =

0x01

TYPE_CLASS =

0x02

TYPE_MODULE =

0x03

TYPE_FLOAT =

0x04

TYPE_STRING =

0x05

TYPE_REGEXP =

0x06

TYPE_ARRAY =

0x07

TYPE_HASH =

0x08

TYPE_STRUCT =

0x09

TYPE_BIGNUM =

0x0a

TYPE_FILE =

0x0b

TYPE_DATA =

0x0c

TYPE_MATCH =

0x0d

TYPE_COMPLEX =

0x0e

TYPE_RATIONAL =

0x0f

TYPE_NIL =

0x11

TYPE_TRUE =

0x12

TYPE_FALSE =

0x13

TYPE_SYMBOL =

0x14

TYPE_FIXNUM =

0x15

TYPE_UNDEF =

0x16

Instance Attribute Summary

• #type ⇒ Object readonly

  Returns the value of attribute type.

Instance Method Summary

• #==(other) ⇒ Object
• #call(vm) ⇒ Object
• #deconstruct_keys(_keys) ⇒ Object
• #disasm(fmt) ⇒ Object
• #initialize(type) ⇒ CheckType constructor

  A new instance of CheckType.

• #length ⇒ Object
• #pops ⇒ Object
• #pushes ⇒ Object
• #to_a(_iseq) ⇒ Object

Methods inherited from Instruction

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

Constructor Details

#initialize(type) ⇒ CheckType

Returns a new instance of CheckType.

# File 'lib/syntax_tree/yarv/instructions.rb', line 526

def initialize(type)
  @type = type
end

Instance Attribute Details

#type ⇒ Object (readonly)

Returns the value of attribute type.

# File 'lib/syntax_tree/yarv/instructions.rb', line 524

def type
  @type
end

Instance Method Details

#==(other) ⇒ Object

# File 'lib/syntax_tree/yarv/instructions.rb', line 588

def ==(other)
  other.is_a?(CheckType) && other.type == type
end

#call(vm) ⇒ Object

# File 'lib/syntax_tree/yarv/instructions.rb', line 608

def call(vm)
  object = vm.pop
  result =
    case type
    when TYPE_OBJECT
      raise NotImplementedError, "checktype TYPE_OBJECT"
    when TYPE_CLASS
      object.is_a?(Class)
    when TYPE_MODULE
      object.is_a?(Module)
    when TYPE_FLOAT
      object.is_a?(Float)
    when TYPE_STRING
      object.is_a?(String)
    when TYPE_REGEXP
      object.is_a?(Regexp)
    when TYPE_ARRAY
      object.is_a?(Array)
    when TYPE_HASH
      object.is_a?(Hash)
    when TYPE_STRUCT
      object.is_a?(Struct)
    when TYPE_BIGNUM
      raise NotImplementedError, "checktype TYPE_BIGNUM"
    when TYPE_FILE
      object.is_a?(File)
    when TYPE_DATA
      raise NotImplementedError, "checktype TYPE_DATA"
    when TYPE_MATCH
      raise NotImplementedError, "checktype TYPE_MATCH"
    when TYPE_COMPLEX
      object.is_a?(Complex)
    when TYPE_RATIONAL
      object.is_a?(Rational)
    when TYPE_NIL
      object.nil?
    when TYPE_TRUE
      object == true
    when TYPE_FALSE
      object == false
    when TYPE_SYMBOL
      object.is_a?(Symbol)
    when TYPE_FIXNUM
      object.is_a?(Integer)
    when TYPE_UNDEF
      raise NotImplementedError, "checktype TYPE_UNDEF"
    end

  vm.push(result)
end

#deconstruct_keys(_keys) ⇒ Object

# File 'lib/syntax_tree/yarv/instructions.rb', line 584

def deconstruct_keys(_keys)
  { type: type }
end

#disasm(fmt) ⇒ Object

# File 'lib/syntax_tree/yarv/instructions.rb', line 530

def disasm(fmt)
  name =
    case type
    when TYPE_OBJECT
      "T_OBJECT"
    when TYPE_CLASS
      "T_CLASS"
    when TYPE_MODULE
      "T_MODULE"
    when TYPE_FLOAT
      "T_FLOAT"
    when TYPE_STRING
      "T_STRING"
    when TYPE_REGEXP
      "T_REGEXP"
    when TYPE_ARRAY
      "T_ARRAY"
    when TYPE_HASH
      "T_HASH"
    when TYPE_STRUCT
      "T_STRUCT"
    when TYPE_BIGNUM
      "T_BIGNUM"
    when TYPE_FILE
      "T_FILE"
    when TYPE_DATA
      "T_DATA"
    when TYPE_MATCH
      "T_MATCH"
    when TYPE_COMPLEX
      "T_COMPLEX"
    when TYPE_RATIONAL
      "T_RATIONAL"
    when TYPE_NIL
      "T_NIL"
    when TYPE_TRUE
      "T_TRUE"
    when TYPE_FALSE
      "T_FALSE"
    when TYPE_SYMBOL
      "T_SYMBOL"
    when TYPE_FIXNUM
      "T_FIXNUM"
    when TYPE_UNDEF
      "T_UNDEF"
    end

  fmt.instruction("checktype", [name])
end

#length ⇒ Object

# File 'lib/syntax_tree/yarv/instructions.rb', line 592

def length
  2
end

#pops ⇒ Object

# File 'lib/syntax_tree/yarv/instructions.rb', line 596

def pops
  1
end

#pushes ⇒ Object

# File 'lib/syntax_tree/yarv/instructions.rb', line 600

def pushes
  # TODO: This is incorrect. The instruction only pushes a single value
  # onto the stack. However, if this is set to 1, we no longer match the
  # output of RubyVM::InstructionSequence. So leaving this here until we
  # can investigate further.
  2
end

#to_a(_iseq) ⇒ Object

# File 'lib/syntax_tree/yarv/instructions.rb', line 580

def to_a(_iseq)
  [:checktype, type]
end