model: treat 'user defined' tokens as special tokens (#11077)

model/vocabulary.go

@@ -87,7 +87,7 @@ func (v *Vocabulary) Decode(id int32) string {
 func (v *Vocabulary) SpecialVocabulary() []string {
 	v.specialOnce.Do(func() {
 		for i := range v.Values {
-			if v.Types[i] == TOKEN_TYPE_CONTROL {
+			if v.Types[i] == TOKEN_TYPE_CONTROL || v.Types[i] == TOKEN_TYPE_USER_DEFINED {
 				v.special = append(v.special, v.Values[i])
 			}
 		}

model/vocabulary_test.go

+package model
+
+import "testing"
+
+func TestVocabulary_SpecialVocabulary(t *testing.T) {
+	vocab := &Vocabulary{
+		Values: []string{"<|startoftext|>", "<|endoftext|>", "<|tool_call_start|>", "<|tool_call_end|>", "hi"},
+		Types:  []int32{TOKEN_TYPE_CONTROL, TOKEN_TYPE_CONTROL, TOKEN_TYPE_USER_DEFINED, TOKEN_TYPE_USER_DEFINED, TOKEN_TYPE_NORMAL},
+	}
+
+	specialVocab := vocab.SpecialVocabulary()
+
+	if len(specialVocab) != 4 {
+		t.Errorf("expected 4 special tokens, got %d", len(specialVocab))
+	}
+}