merge v0.23.0-rc changes

core/validators/string.go

@@ -0,0 +1,29 @@
+package validators
+
+import (
+	"regexp"
+
+	validation "github.com/go-ozzo/ozzo-validation/v4"
+)
+
+// IsRegex checks whether the validated value is a valid regular expression pattern.
+//
+// Example:
+//
+//	validation.Field(&form.Pattern, validation.By(validators.IsRegex))
+func IsRegex(value any) error {
+	v, ok := value.(string)
+	if !ok {
+		return ErrUnsupportedValueType
+	}
+
+	if v == "" {
+		return nil // nothing to check
+	}
+
+	if _, err := regexp.Compile(v); err != nil {
+		return validation.NewError("validation_invalid_regex", err.Error())
+	}
+
+	return nil
+}