moved a subset of source file to the kern package

t_simple-store_test.go

@@ -0,0 +1,19 @@
+// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
+// All rights reserved.
+
+// t_simple-store_test.go
+package expr
+
+import (
+	"testing"
+)
+
+func TestGetVar(t *testing.T) {
+	ctx := NewSimpleStoreWithoutGlobalContext()
+	ctx.SetVar("x", 10)
+	if value, exists := ctx.GetVar("x"); !exists {
+		t.Errorf("missing variable 'x'")
+	} else if value != int64(10) {
+		t.Errorf("expcted 10, got %v", value)
+	}
+}