add better error messages on invalid input

terdle.c

@@ -121,46 +121,41 @@ result_set_t guess_match(word_t answer_word, word_t guess_word) {
 /* returns whether or not the game was won */
 typedef struct wordle_game {
   word_t target;
-  uint32_t turn_limit;
+  uint32_t turn_number, turn_limit;
   int (*guess_fn)(word_t *, void *);
   void *guess_fn_data;
   void (*display_fn)(result_set_t, void *);
   void *display_fn_data;
 } wordle_game_t;
 
-bool play_game(wordle_game_t *game) {
-  for (uint32_t turn = 1; turn <= game->turn_limit; ++turn) {
-    word_t guess = 0;
-    if (game->guess_fn(&guess, game->guess_fn_data) != 0) {
-      printf("guesser failure\n");
-    }
-    result_set_t result_set = guess_match(game->target, guess);
-    game->display_fn(result_set, game->display_fn_data);
-    if (guess == game->target) {
-      return true;
-    }
-  }
-  return false;
-}
-
 struct linebuf {
   char *buffer;
   size_t capacity;
 };
 
+/* the guess function returns 0 on success and something else on failure */
 int term_guess(word_t *word, void *data) {
   struct linebuf *linebuf = data;
   while (true) {
+    fputs("guess> ", stdout);
     ssize_t bytes_read = getline(&(linebuf->buffer), &(linebuf->capacity), stdin);
+    /* if the input is closed, there's no way to recover. fail out */
     if (bytes_read == -1) {
       return -1;
     }
     char *buf_end = linebuf->buffer;
     strsep(&buf_end, "\n");
-    if (strchr(linebuf->buffer, '\0') - linebuf->buffer == WORD_LENGTH) {
+    size_t length = strchr(linebuf->buffer, '\0') - linebuf->buffer;
+    /* some basic error checking around length */
+    if (length == WORD_LENGTH) {
       *word = strtoword(linebuf->buffer);
       return 0;
     } else {
+      if (length > WORD_LENGTH) {
+        fprintf(stderr, "error: too long\n");
+      } else {
+        fprintf(stderr, "error: too short\n");
+      }
       continue;
     }
   }
@@ -168,6 +163,7 @@ int term_guess(word_t *word, void *data) {
 
 void term_display(result_set_t result_set, void *ignored) {
   (void) ignored;
+  fputs("result ", stdout);
   for (size_t i = 0; i < WORD_LENGTH; ++i) {
     switch (rs_get(result_set, i)) {
       case RES_BLACK:
@@ -184,10 +180,25 @@ void term_display(result_set_t result_set, void *ignored) {
         break;
     }
   }
-  fputs(" result", stdout);
   fputc('\n', stdout);
 }
 
+bool play_game(wordle_game_t *game) {
+  for (game->turn_number = 1; game->turn_number <= game->turn_limit; ++game->turn_number) {
+    word_t guess = 0;
+    if (game->guess_fn(&guess, game->guess_fn_data) != 0) {
+      printf("guesser failure\n");
+      break;
+    }
+    result_set_t result_set = guess_match(game->target, guess);
+    game->display_fn(result_set, game->display_fn_data);
+    if (guess == game->target) {
+      return true;
+    }
+  }
+  return false;
+}
+
 int main(int argc, char *argv[]) {
   struct linebuf lb = {
     .capacity = 6,
@@ -195,13 +206,18 @@ int main(int argc, char *argv[]) {
   };
   wordle_game_t game = {
     .target = strtoword("total"),
+    .turn_number = 0,
     .turn_limit = 6,
     .guess_fn = term_guess,
     .guess_fn_data = &lb,
     .display_fn = term_display,
     .display_fn_data = NULL,
   };
-  int x = play_game(&game);
-  printf("endgame %d\n", x);
+  bool won = play_game(&game);
+  if (won) {
+    fprintf(stdout, "YOU WIN %d/%d\n", game.turn_number, game.turn_limit);
+  } else {
+    fprintf(stdout, "YOU LOSE\n");
+  }
   return 0;
 }