Artifact 94485181e809cc7b0fcf748b3ee57855399df9a0

• File sample/ast.pmy
  • 2010-11-23 10:37:54 - part of checkin [5e924caac9] on branch trunk - added AST-rewriting macro sample. (user: kinaba) [annotate]

def reverse(lst, acc)
{
	case(lst)
		when( {car:a, cdr: d} ) { reverse(d, {car:a, cdr:acc}) }
		when( {} ) { acc }
};

@macro reverseArgs(e) {@value(
	var ev = @macro(e);
	case(ev)
		when( {is:"app", fun:f, args:a} )
		{
			ev {args: reverse(a, {})}
		}
		when( _ ) 
		{
			ev
		}
)};

def main()
{
	print( reverseArgs(1 + 2) );
	print( reverseArgs(1 - 2) );
};

main()