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 1773

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 1771

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 1771

def level
  @level
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1792

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 1804

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 1788

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

#disasm(fmt) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1778

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 1796

def length
  3
end

#pushes ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1800

def pushes
  1
end

#to_a(iseq) ⇒ Object 



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# File 'lib/syntax_tree/yarv/instructions.rb', line 1782

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