ok getting closer, and manually verified correctness of the schema matching python. still some weirdness in the printing to chase down, and also have to tune the buffer lengths and make them sensible and such

run.c

@@ -839,7 +839,7 @@ void chat(Transformer *transformer, Tokenizer *tokenizer, Sampler *sampler,
                 strcpy(user_prompt, cli_user_prompt);
             } else {
                 // otherwise get user prompt from stdin
-                read_stdin("Enter user prompt: ", user_prompt, sizeof(user_prompt));
+                read_stdin("User: ", user_prompt, sizeof(user_prompt));
             }
             // render user/system prompts into the Llama 2 Chat schema
             if (pos == 0 && system_prompt[0] != '\0') {
@@ -853,10 +853,10 @@ void chat(Transformer *transformer, Tokenizer *tokenizer, Sampler *sampler,
             encode(tokenizer, rendered_prompt, 1, 0, prompt_tokens, &num_prompt_tokens);
             user_idx = 0; // reset the user index
             user_turn = 0;
+            printf("Assistant: ");
         }
 
         // determine the token to pass into the transformer next
-        prev_token = token;
         if (user_idx < num_prompt_tokens) {
             // if we are still processing the input prompt, force the next prompt token
             token = prompt_tokens[user_idx++];
@@ -872,11 +872,14 @@ void chat(Transformer *transformer, Tokenizer *tokenizer, Sampler *sampler,
         next = sample(sampler, logits);
         pos++;
 
-        // print the token as string, decode it with the Tokenizer object
+        if (user_idx >= num_prompt_tokens && next != 2) {
-        char* piece = decode(tokenizer, prev_token, token);
+            // the Assistant is responding, so print its output
+            char* piece = decode(tokenizer, token, next);
             safe_printf(piece); // same as printf("%s", piece), but skips "unsafe" bytes
             fflush(stdout);
         }
+        if (next == 2) { printf("\n"); }
+    }
     printf("\n");
     free(prompt_tokens);
 }