utils.go: new function toInt() converts any(int64) to int

utils.go

@@ -5,6 +5,7 @@
 package expr
 
 import (
+	"fmt"
 	"reflect"
 )
 
@@ -168,3 +169,12 @@ func CloneFilteredMap[K comparable, V any](source map[K]V, filter func(key K) (a
 	dest := make(map[K]V, len(source))
 	return CopyFilteredMap(dest, source, filter)
 }
+
+func toInt(value any, description string) (i int, err error) {
+	if valueInt64, ok := value.(int64); ok {
+		i = int(valueInt64)
+	} else {
+		err = fmt.Errorf("%s expected integer, got %T (%v)", description, value, value)
+	}
+	return
+}