Class: SyntaxTree::YARV::GetInstanceVariable

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

Overview

### Summary

getinstancevariable pushes the value of an instance variable onto the stack. It uses an inline cache to avoid having to look up the instance variable in the class hierarchy every time.

This instruction has two forms, but both have the same structure. Before Ruby 3.2, the inline cache corresponded to both the get and set instructions and could be shared. Since Ruby 3.2, it uses object shapes instead so the caches are unique per instruction.

### Usage

~~~ruby ~~~

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, cache) ⇒ GetInstanceVariable 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1665

def initialize(name, cache)
  @name = name
  @cache = cache
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 1663

def cache
  @cache
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1663

def name
  @name
end

Instance Method Details

#call(vm) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1697

def call(vm)
  method = Object.instance_method(:instance_variable_get)
  vm.push(method.bind(vm.frame._self).call(name))
end

#canonical ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1693

def canonical
  self
end

#disasm(fmt) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1670

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

#length ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1681

def length
  3
end

#pops ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1685

def pops
  0
end

#pushes ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1689

def pushes
  1
end

#to_a(_iseq) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1677

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