From 47092488288de0bf1ce4d70b82f633f03c22fe6a Mon Sep 17 00:00:00 2001
From: Celestino Amoroso <celestino.amoroso@gmail.com>
Date: Thu, 13 Nov 2025 20:53:07 +0100
Subject: [PATCH] string builtin: strUpper() and strLower() added

---
 builtin-string.go        | 26 ++++++++++++++++++++++++++
 t_builtin-string_test.go |  2 ++
 2 files changed, 28 insertions(+)

diff --git a/builtin-string.go b/builtin-string.go
index 6a9df5c..a139452 100644
--- a/builtin-string.go
+++ b/builtin-string.go
@@ -200,6 +200,24 @@ func splitStrFunc(ctx ExprContext, name string, args map[string]any) (result any
 	return
 }
 
+func upperStrFunc(ctx ExprContext, name string, args map[string]any) (result any, err error) {
+	if source, ok := args[ParamSource].(string); ok {
+		result = strings.ToUpper(source)
+	} else {
+		err = ErrWrongParamType(name, ParamSource, TypeString, args[ParamSource])
+	}
+	return
+}
+
+func lowerStrFunc(ctx ExprContext, name string, args map[string]any) (result any, err error) {
+	if source, ok := args[ParamSource].(string); ok {
+		result = strings.ToLower(source)
+	} else {
+		err = ErrWrongParamType(name, ParamSource, TypeString, args[ParamSource])
+	}
+	return
+}
+
 // --- End of function definitions
 
 // Import above functions in the context
@@ -236,6 +254,14 @@ func ImportStringFuncs(ctx ExprContext) {
 		NewFuncParam(ParamSuffix),
 		NewFuncParamFlag(strParamOther, PfRepeat),
 	})
+
+	ctx.RegisterFunc("strUpper", NewGolangFunctor(upperStrFunc), TypeBoolean, []ExprFuncParam{
+		NewFuncParam(ParamSource),
+	})
+
+	ctx.RegisterFunc("strLower", NewGolangFunctor(lowerStrFunc), TypeBoolean, []ExprFuncParam{
+		NewFuncParam(ParamSource),
+	})
 }
 
 // Register the import function in the import-register.
diff --git a/t_builtin-string_test.go b/t_builtin-string_test.go
index 99e0a47..46500c0 100644
--- a/t_builtin-string_test.go
+++ b/t_builtin-string_test.go
@@ -31,6 +31,8 @@ func TestFuncString(t *testing.T) {
 		/*  17 */ {`builtin "string"; strSplit("one-two-three", "-")`, newListA("one", "two", "three"), nil},
 		/*  18 */ {`builtin "string"; strJoin("-", [1, "two", "three"])`, nil, `strJoin(): expected string, got integer (1)`},
 		/*  19 */ {`builtin "string"; strJoin()`, nil, `strJoin(): too few params -- expected 1 or more, got 0`},
+		/*  20 */ {`builtin "string"; strUpper("StOp")`, "STOP", nil},
+		/*  21 */ {`builtin "string"; strLower("StOp")`, "stop", nil},
 
 		/*  69 */ /*{`builtin "string"; $$global`, `vars: {
 		}