func-*.go modules renamed as builtin-*.go.

Also changed and exported some identiefier relatet to the builtin feature

builtin-fmt.go

@@ -0,0 +1,36 @@
+// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
+// All rights reserved.
+
+// builtin-fmt.go
+package expr
+
+import "fmt"
+
+func printFunc(ctx ExprContext, name string, args []any) (result any, err error) {
+	var n int
+	if n, err = fmt.Print(args...); err == nil {
+		result = int64(n)
+	}
+	return
+}
+
+func printLnFunc(ctx ExprContext, name string, args []any) (result any, err error) {
+	var n int
+	if n, err = fmt.Println(args...); err == nil {
+		result = int64(n)
+	}
+	return
+}
+
+func ImportFmtFuncs(ctx ExprContext) {
+	ctx.RegisterFunc("print", NewGolangFunctor(printFunc), TypeInt, []ExprFuncParam{
+		NewFuncParamFlag(ParamItem, PfRepeat),
+	})
+	ctx.RegisterFunc("println", NewGolangFunctor(printLnFunc), TypeInt, []ExprFuncParam{
+		NewFuncParamFlag(ParamItem, PfRepeat),
+	})
+}
+
+func init() {
+	RegisterBuiltinModule("fmt", ImportFmtFuncs, "String and console formatting functions")
+}