Remove ill-advised code

webutil/formscanner.go

@@ -8,17 +8,9 @@ import (
 
 var ErrUnsupportedType = errors.New("unsupported type")
 
-// FormScanFunc is a custom form scanner that can be used to scan custom
-// types using the form scanner.
-//
-// It returns true if it recognizes the type of val, and an error if scanning
-// fails.
-type FormScanFunc func(name string, val any) (bool, error)
-
 type FormScanner struct {
-	form     url.Values
-	err      error
-	ScanFunc FormScanFunc
+	form url.Values
+	err  error
 }
 
 func NewFormScanner(form url.Values) *FormScanner {
@@ -30,13 +22,6 @@ func (s *FormScanner) Scan(name string, val any) *FormScanner {
 		return s
 	}
 
-	if s.ScanFunc != nil {
-		if ok, err := s.ScanFunc(name, val); ok {
-			s.err = err
-			return s
-		}
-	}
-
 	switch v := val.(type) {
 	case *bool:
 		*v = s.form.Has(name)
@@ -52,3 +37,7 @@ func (s *FormScanner) Scan(name string, val any) *FormScanner {
 func (s *FormScanner) Error() error {
 	return s.err
 }
+
+func (s *FormScanner) SetError(err error) {
+	s.err = err
+}