Class: Preval::Visitors::Loops

Inherits:
Preval::Visitor show all
Defined in:
lib/preval/visitors/loops.rb

Instance Method Summary collapse

Methods inherited from Preval::Visitor

enable!

Instance Method Details

#on_for(node) ⇒ Object 



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# File 'lib/preval/visitors/loops.rb', line 6

def on_for(node)
  ast = Parser.parse(<<~CODE)
    #{node.source(1)}.each do |#{node.source(0)}|
      #{node.source(2)}
    end
  CODE

  node.update(:stmts_add, ast[0].body)
end

#on_until(node) ⇒ Object 



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# File 'lib/preval/visitors/loops.rb', line 46

def on_until(node)
  # auto replace `until false` with `loop do`
  if node[0].is?(:var_ref) &&
     # the predicate to the while is a variable reference
     node[0, 0].is?(:@kw) &&
     # the variable reference is a keyword
     node[0, 0].body == 'false'
     # the keyword is "false"

    ast = Parser.parse(<<~CODE)
      loop do
        #{node.source(1)}
      end
    CODE

    node.update(:stmts_add, ast[0].body)
  end

  # ignore `until true`
  if node[0].is?(:var_ref) &&
     # the predicate to the until is a variable reference
     node[0, 0].is?(:@kw) &&
     # the variable reference is a keyword
     node[0, 0].body == 'true'
     # the kwyword is "true"

    node.update(:void_stmt, [])
  end
end

#on_while(node) ⇒ Object 



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# File 'lib/preval/visitors/loops.rb', line 16

def on_while(node)
  # auto replace `while true` with `loop do`
  if node[0].is?(:var_ref) &&
     # the predicate to the while is a variable reference
     node[0, 0].is?(:@kw) &&
     # the variable reference is a keyword
     node[0, 0].body == 'true'
     # the keyword is "true"

    ast = Parser.parse(<<~CODE)
      loop do
        #{node.source(1)}
      end
    CODE

    node.update(:stmts_add, ast[0].body)
  end

  # ignore `while false`
  if node[0].is?(:var_ref) &&
     # the predicate to the while is a variable reference
     node[0, 0].is?(:@kw) &&
     # the variable reference is a keyword
     node[0, 0].body == 'false'
     # the kwyword is "false"

    node.update(:void_stmt, [])
  end
end