feat: better error messages

pkg/saccharine/tokenizer.go

@@ -7,6 +7,7 @@ import (
 
 	"git.maximhutz.com/max/lambda/pkg/iterator"
 	"git.maximhutz.com/max/lambda/pkg/saccharine/token"
+	"git.maximhutz.com/max/lambda/pkg/trace"
 )
 
 // isVariables determines whether a rune can be a valid variable.
@@ -38,7 +39,7 @@ func getToken(i *iterator.Iterator[rune]) (*token.Token, error) {
 
 	letter, err := i.Next()
 	if err != nil {
-		return nil, fmt.Errorf("cannot produce next token: %w", err)
+		return nil, trace.WrapError(fmt.Errorf("cannot produce next token"), err)
 	}
 
 	switch {
@@ -50,6 +51,8 @@ func getToken(i *iterator.Iterator[rune]) (*token.Token, error) {
 		return token.NewDot(index), nil
 	case letter == '\\':
 		return token.NewSlash(index), nil
+	case letter == '\n':
+		return token.NewNewline(index), nil
 	case unicode.IsSpace(letter):
 		return nil, nil
 	case isVariable(letter):