Generalize histogram printing to accept a predicate function

[mnemon] / mnemon.c

diff --git a/mnemon.c b/mnemon.c
index 52a77d02ff82a430108748b76d5714aa6a057e30..446d449b736d1bb2a1743688aa7bc6d86d19a4dc 100644 (file)
--- a/mnemon.c
+++ b/mnemon.c
@@ -323,6 +323,27 @@ bin_item_index (bin_t      *bin,
     assert (0);
 }
 
+typedef int (item_match_predicate_t) (void *closure, item_t *item);
+
+/* Return the number of items in the bin from the given category (or
+ * from all categories if category == NULL) */
+static int
+bin_num_items_matching (bin_t                  *bin,
+                       item_match_predicate_t  *predicate,
+                       void                    *closure)
+{
+    int i, num_items = 0;
+
+    if (predicate == NULL)
+       return bin->num_items;
+
+    for (i = 0; i < bin->num_items; i++)
+       if ((predicate) (closure, bin->items[i]))
+           num_items++;
+
+    return num_items;
+}
+
 static void
 mnemon_init (mnemon_t *mnemon)
 {
@@ -760,23 +781,20 @@ mnemon_item_category (mnemon_t    *mnemon,
     assert (0);
 }
 
-/* Return the number of items in the bin from the given category (or
- * from all categories if category == NULL) */
-static int
-mnemon_bin_num_items_in_category (mnemon_t     *mnemon,
-                                 bin_t         *bin,
-                                 category_t    *category)
+typedef struct _item_in_category_closure
 {
-    int i, num_items = 0;
-
-    if (category == NULL)
-       return bin->num_items;
+    mnemon_t *mnemon;
+    category_t *category;
+} item_in_category_closure_t;
 
-    for (i = 0; i < bin->num_items; i++)
-       if (mnemon_item_category (mnemon, bin->items[i]) == category)
-           num_items++;
+static int
+mnemon_item_in_category (void *closure, item_t *item)
+{
+    item_in_category_closure_t *iicc = closure;
+    mnemon_t *mnemon = iicc->mnemon;
+    category_t *category = iicc->category;
 
-    return num_items;
+    return (mnemon_item_category (mnemon, item) == category);
 }
 
 static void
@@ -861,17 +879,26 @@ mnemon_print_histogram (mnemon_t    *mnemon,
     category_t *category = NULL;
     bin_t *bin;
     int num_items;
+    item_match_predicate_t *predicate = NULL;
+    void *closure = NULL;
+    item_in_category_closure_t item_in_category;
 
     if (mnemon->num_bins == 0)
        return;
 
-    if (category_name)
+    if (category_name) {
        category = mnemon_get_category_if_exists (mnemon, category_name);
+       if (category) {
+           predicate = mnemon_item_in_category;
+           item_in_category.mnemon = mnemon;
+           item_in_category.category = category;
+           closure = &item_in_category;
+       }
+    }
 
     for (i = 0; i < mnemon->num_bins; i++) {
-       num_items = mnemon_bin_num_items_in_category (mnemon,
-                                                     &mnemon->bins[i],
-                                                     category);
+       num_items = bin_num_items_matching (&mnemon->bins[i],
+                                           predicate, closure);
        if (i == 0 || num_items > max)
            max = num_items;
     }
@@ -881,8 +908,8 @@ mnemon_print_histogram (mnemon_t    *mnemon,
        if (i != 0)
            while (bin->score - last_score > 1)
                printf (HISTOGRAM_ROW_FORMAT "\n", ++last_score, 0);
-       num_items = mnemon_bin_num_items_in_category (mnemon,
-                                                     bin, category);
+       num_items = bin_num_items_matching (bin,
+                                           predicate, closure);
        printf (HISTOGRAM_ROW_FORMAT " ", bin->score, num_items);
        print_histogram_bar (num_items, max);
        last_score = bin->score;