"define without value",
		"#define A",
		"",
	},
	{
		"macro without arguments",
		"#define A() 1234\n" + "A()\n",
		"1234.\n",
	},
	{
		"macro with just parens as body",
		"#define A () \n" + "A\n",
		"(.).\n",
	},
	{
		"macro with parens but no arguments",
		"#define A (x) \n" + "A\n",
		"(.x.).\n",
	},
	{
		"macro with arguments",
		"#define A(x, y, z) x+z+y\n" + "A(1, 2, 3)\n",
		"1.+.3.+.2.\n",

	}
	in.macros[name] = &Macro{
		name:   name,
		args:   args,
		tokens: tokens,
	}
}

// macroDefinition returns the list of formals and the tokens of the definition.
// The argument list is nil for no parens on the definition; otherwise a list of
// formal argument names.
func (in *Input) macroDefinition(name string) ([]string, []Token) {
	prevCol := in.Stack.Col()
	tok := in.Stack.Next()