A lot of changes. Main ones are:

- fraction type renamed as FractionType and moved from operator-fraction.go to fraction-type.go
- ListType moved from operator-list.go to list-type.go
- all test file were renamed adding the "t_" prefix
- defined a test template in file t_temple_test.go
- new test file t_relational_test.go where relational tests are collected
- lists can now compared as set using operators <, <=, >, and >= (IMPORTANT: here = menas same content, not same list)

t_token_test.go

@@ -0,0 +1,39 @@
+// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
+// All rights reserved.
+
+// t_token_test.go
+package expr
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestDevString(t *testing.T) {
+	type inputType struct {
+		source     string
+		sym        Symbol
+		value      any
+		wantResult string
+	}
+
+	inputs := []inputType{
+		/*   1 */ {"100", SymInteger, 100, fmt.Sprintf(`[%d]"100"{100}`, SymInteger)},
+		/*   2 */ {"+", SymPlus, nil, fmt.Sprintf(`[%d]"+"{}`, SymPlus)},
+	}
+
+	for i, input := range inputs {
+		var tk *Token
+		if input.value == nil {
+			tk = NewToken(0, 0, input.sym, input.source)
+		} else {
+			tk = NewValueToken(0, 0, input.sym, input.source, input.value)
+		}
+
+		t.Logf("Test nr %2d: %q --> %q", i+1, input.source, input.wantResult)
+
+		if s := tk.DevString(); s != input.wantResult {
+			t.Errorf("wrong token from symbol '+': expected %q, got %q", input.wantResult, s)
+		}
+	}
+}