From f3f6c0a930c155f43ca7a3ce8ebb428dfc4116ed Mon Sep 17 00:00:00 2001
From: jaime-m-p <>
Date: Mon, 27 May 2024 20:17:01 +0200
Subject: [PATCH] Discard all tokens when no matching found

---
 llama.cpp | 28 +++++++++++++---------------
 1 file changed, 13 insertions(+), 15 deletions(-)

diff --git a/llama.cpp b/llama.cpp
index 502ef5972..b2a67a99b 100644
--- a/llama.cpp
+++ b/llama.cpp
@@ -12660,7 +12660,7 @@ struct llm_tokenizer_wpm {
     llm_tokenizer_wpm(const llama_vocab & vocab): vocab(vocab) {}
 
     void tokenize(const std::string & text, std::vector<llama_vocab::id> & output) {
-        auto * token_map = &vocab.token_to_id;
+        const auto & token_map = vocab.token_to_id;
 
         // normalize and split by whitespace
         std::vector<std::string> words = preprocess(text);
@@ -12675,36 +12675,34 @@ struct llm_tokenizer_wpm {
             }
 
             // prepend phantom space
-            std::string word1 = "\xe2\x96\x81" + word;
-            int n = word1.size();
+            const std::string word1 = "\xe2\x96\x81" + word;
+            const int n = word1.size();
+
+            const size_t current_tokens = output.size();
 
             // we're at the start of a new word
-            int i = 0;
-            bool match_any = false;
-
             // move through character position in word
-            while (i < n) {
+            for (int i = 0; i < n; ++i) {
                 // loop through possible match length
                 bool match = false;
                 for (int j = n; j > i; j--) {
-                    auto it = token_map->find(word1.substr(i, j - i));
-                    if (it != token_map->end()) {
+                    auto it = token_map.find(word1.substr(i, j - i));
+                    if (it != token_map.end()) {
                         output.push_back(it->second);
                         match = true;
-                        match_any = true;
-                        i = j;
+                        i = j - 1;
                         break;
                     }
                 }
 
-                // must be an unknown character
-                if (!match) {
-                    i++;
+                if (!match) { // discard all
+                    output.resize(current_tokens);
+                    break;  // and discard next tokens
                 }
             }
 
             // we didn't find any matches for this word
-            if (!match_any) {
+            if (current_tokens == output.size()) {
                 output.push_back(vocab.special_unk_id);
             }
         }