x@(Syntax LoadVariable traits) swapWith: y@(Syntax LoadVariable traits) &environment: env
"A macro that expands into simple code swapping the values of two variables
in the current scope."
[
  env ifNil: [error: 'Cannot swap variables outside of a method'].
  tmpVar ::= env addVariable.
  {tmpVar store: x variable load.
   x variable store: y variable load.
   y variable store: tmpVar load} parenthesize
].