in.peek = true
		in.Push(NewSlice(in.Base(), in.Line(), []Token{Make(macroName, macro.name)}))
		return
	}
	actuals := in.argsFor(macro)
	var tokens []Token
	for _, tok := range macro.tokens {
		if tok.ScanToken != scanner.Ident {
			tokens = append(tokens, tok)
			continue
		}
		substitution := actuals[tok.text]
		if substitution == nil {
			tokens = append(tokens, tok)
			continue
		}