Class: Audition::Rewriters::Memoization::SingletonIvars

Inherits:
Prism::Visitor
  • Object
show all
Defined in:
lib/audition/rewriters.rb

Overview

Collects ivar operations that touch the class object: inside def self.x, inside class << self methods, or directly in the class body (recorded with body: true, which disqualifies the group). Instance-method ivars are ignored.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ SingletonIvars

Returns a new instance of SingletonIvars.



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# File 'lib/audition/rewriters.rb', line 614

def initialize
  @groups = Hash.new { |h, k| h[k] = [] }
  @namespace = []
  @sclass_depth = 0
  @def_stack = []
  @defined_depth = 0
  super
end

Instance Attribute Details

#groups ⇒ Object (readonly)

Returns the value of attribute groups.



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# File 'lib/audition/rewriters.rb', line 612

def groups
  @groups
end

Instance Method Details

#visit_class_node(node) ⇒ Object 



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# File 'lib/audition/rewriters.rb', line 623

def visit_class_node(node)
  scoped(node.constant_path.location.slice, :class) do
    super(node)
  end
end

#visit_def_node(node) ⇒ Object 



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# File 'lib/audition/rewriters.rb', line 648

def visit_def_node(node)
  kind =
    node.receiver.is_a?(Prism::SelfNode) ? :self : :plain
  @def_stack.push(
    {kind: kind, id: node.object_id,
     name: node.name, node: node}
  )
  super
ensure
  @def_stack.pop
end

#visit_defined_node(node) ⇒ Object

A defined?(@x) that is not the recognized guard idiom probes ivar presence; rewriting the read to Ractor storage would make the probe unconditionally true, so every op inside disqualifies its group (recorded as :other).



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# File 'lib/audition/rewriters.rb', line 665

def visit_defined_node(node)
  @defined_depth += 1
  super
ensure
  @defined_depth -= 1
end

#visit_if_node(node) ⇒ Object

Matches the guard statement of the second memoization idiom: return @x if defined?(@x). On a match the inner reads are not visited (they belong to the guard, not to the data flow) and the whole statement is recorded so the planner can delete it.



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# File 'lib/audition/rewriters.rb', line 677

def visit_if_node(node)
  name = guard_name(node)
  if name
    record(node, :guard, name)
  else
    super
  end
end

#visit_module_node(node) ⇒ Object 



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# File 'lib/audition/rewriters.rb', line 629

def visit_module_node(node)
  scoped(node.constant_path.location.slice, :module) do
    super(node)
  end
end

#visit_singleton_class_node(node) ⇒ Object 



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# File 'lib/audition/rewriters.rb', line 635

def visit_singleton_class_node(node)
  if node.expression.is_a?(Prism::SelfNode)
    @sclass_depth += 1
    begin
      super
    ensure
      @sclass_depth -= 1
    end
  else
    super
  end
end