Class: SyntaxTree::YARV::DefinedIVar

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

Overview

### Summary

‘definedivar` checks if an instance variable is defined. It is a specialization of the `defined` instruction. It accepts three arguments: the name of the instance variable, an inline cache, and the string that should be pushed onto the stack in the event that the instance variable is defined.

### Usage

~~~ruby defined?(@value) ~~~

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from Instruction

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

Constructor Details

#initialize(name, cache, message) ⇒ DefinedIVar

Returns a new instance of DefinedIVar.



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1067

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

Instance Attribute Details

#cache ⇒ Object (readonly)

Returns the value of attribute cache.



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1065

def cache
  @cache
end

#message ⇒ Object (readonly)

Returns the value of attribute message.



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1065

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 1065

def name
  @name
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1088

def ==(other)
  other.is_a?(DefinedIVar) && other.name == name &&
    other.cache == cache && other.message == message
end

#call(vm) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1101

def call(vm)
  result = (message if vm.frame._self.instance_variable_defined?(name))

  vm.push(result)
end

#deconstruct_keys(_keys) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1084

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

#disasm(fmt) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1073

def disasm(fmt)
  fmt.instruction(
    "definedivar",
    [fmt.object(name), fmt.inline_storage(cache), fmt.object(message)]
  )
end

#length ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1093

def length
  4
end

#pushes ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1097

def pushes
  1
end

#to_a(_iseq) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1080

def to_a(_iseq)
  [:definedivar, name, cache, message]
end