Class: SyntaxTree::YARV::GetLocal

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

Overview

### Summary

‘getlocal` fetches the value of a local variable from a frame determined by the level and index arguments. The level is the number of frames back to look and the index is the index in the local table. It pushes the value it finds onto the stack.

### Usage

~~~ruby value = 5 tap { tap { 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(index, level) ⇒ GetLocal

Returns a new instance of GetLocal.



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1831

def initialize(index, level)
  @index = index
  @level = level
end

Instance Attribute Details

#index ⇒ Object (readonly)

Returns the value of attribute index.



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1829

def index
  @index
end

#level ⇒ Object (readonly)

Returns the value of attribute level.



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1829

def level
  @level
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1850

def ==(other)
  other.is_a?(GetLocal) && other.index == index && other.level == level
end

#call(vm) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1862

def call(vm)
  vm.push(vm.local_get(index, level))
end

#deconstruct_keys(_keys) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1846

def deconstruct_keys(_keys)
  { index: index, level: level }
end

#disasm(fmt) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1836

def disasm(fmt)
  fmt.instruction("getlocal", [fmt.local(index, explicit: level)])
end

#length ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1854

def length
  3
end

#pushes ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1858

def pushes
  1
end

#to_a(iseq) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1840

def to_a(iseq)
  current = iseq
  level.times { current = current.parent_iseq }
  [:getlocal, current.local_table.offset(index), level]
end