Add iter index functions

src/guf_dbuf.h

@@ -3,7 +3,7 @@
     #include "guf_common.h"
     #include "guf_assert.h"
     #include "guf_alloc.h"
-    #define GUF_DBUF_FOREACH(DBUF, ELEM_TYPE, ELEM_PTR_NAME) for (ELEM_TYPE *ELEM_PTR_NAME = (DBUF).data, *end = (DBUF).data ? (DBUF).data + (DBUF).size : NULL; ELEM_PTR_NAME != end; ++ELEM_PTR_NAME)
+    #define GUF_DBUF_FOREACH(DBUF, ELEM_TYPE, ELEM_PTR_NAME) for (ELEM_TYPE *ELEM_PTR_NAME = (DBUF).data, *guf_foreach_end = (DBUF).data ? (DBUF).data + (DBUF).size : NULL; ELEM_PTR_NAME != guf_foreach_end; ++ELEM_PTR_NAME)
 #endif
 
 /*
@@ -124,11 +124,14 @@ GUF_FN_KEYWORDS GUF_CAT(GUF_CNT_NAME, _iter) GUF_CAT(GUF_CNT_NAME, _end)(const G
 GUF_FN_KEYWORDS GUF_CAT(GUF_CNT_NAME, _iter) GUF_CAT(GUF_CNT_NAME, _rbegin)(const GUF_CNT_NAME* dbuf);
 GUF_FN_KEYWORDS GUF_CAT(GUF_CNT_NAME, _iter) GUF_CAT(GUF_CNT_NAME, _rend)(const GUF_CNT_NAME* dbuf);
 GUF_FN_KEYWORDS GUF_CAT(GUF_CNT_NAME, _iter) GUF_CAT(GUF_CNT_NAME, _iter_next)(const GUF_CNT_NAME *dbuf, GUF_CAT(GUF_CNT_NAME, _iter) it, ptrdiff_t step);
+GUF_FN_KEYWORDS  GUF_CAT(GUF_CNT_NAME, _iter) GUF_CAT(GUF_CNT_NAME, _iter_at_idx)(const GUF_CNT_NAME* dbuf, ptrdiff_t idx);
+GUF_FN_KEYWORDS  GUF_CAT(GUF_CNT_NAME, _iter) GUF_CAT(GUF_CNT_NAME, _reverse_iter_at_idx)(const GUF_CNT_NAME* dbuf, ptrdiff_t idx);
+GUF_FN_KEYWORDS ptrdiff_t GUF_CAT(GUF_CNT_NAME, _iter_to_idx)(const GUF_CNT_NAME* dbuf, GUF_CAT(GUF_CNT_NAME, _iter) it);
 
 #if defined(GUF_T_IS_INTEGRAL_TYPE) || defined(GUF_T_EQ)
 GUF_FN_KEYWORDS GUF_CAT(GUF_CNT_NAME, _iter) GUF_CAT(GUF_CNT_NAME, _find)(GUF_CNT_NAME *dbuf, GUF_CAT(GUF_CNT_NAME, _iter) begin, GUF_CAT(GUF_CNT_NAME, _iter) end, const GUF_T *needle);
 GUF_FN_KEYWORDS GUF_CAT(GUF_CNT_NAME, _iter) GUF_CAT(GUF_CNT_NAME, _find_val)(GUF_CNT_NAME *dbuf, GUF_CAT(GUF_CNT_NAME, _iter) begin, GUF_CAT(GUF_CNT_NAME, _iter) end, GUF_T needle_val);
-GUF_FN_KEYWORDS GUF_CAT(GUF_CNT_NAME, _iter) GUF_CAT(GUF_CNT_NAME, _find_if)(GUF_CNT_NAME *dbuf, GUF_CAT(GUF_CNT_NAME, _iter) *begin, GUF_CAT(GUF_CNT_NAME, _iter) *end, bool (*predicate)(const GUF_T *));
+GUF_FN_KEYWORDS GUF_CAT(GUF_CNT_NAME, _iter) GUF_CAT(GUF_CNT_NAME, _find_if)(GUF_CNT_NAME *dbuf, GUF_CAT(GUF_CNT_NAME, _iter) begin, GUF_CAT(GUF_CNT_NAME, _iter) end, bool (*predicate)(const GUF_T *));
 #endif
 
 #if defined(GUF_IMPL) || defined(GUF_IMPL_STATIC)
@@ -756,6 +759,8 @@ GUF_FN_KEYWORDS void GUF_CAT(GUF_CNT_NAME, _try_shrink_to_fit)(GUF_CNT_NAME *dbu
 }
 
 
+/* Iterator functions */
+
 GUF_FN_KEYWORDS GUF_CAT(GUF_CNT_NAME, _iter) GUF_CAT(GUF_CNT_NAME, _begin)(const GUF_CNT_NAME* dbuf)
 {
     GUF_ASSERT_RELEASE(GUF_CAT(GUF_CNT_NAME, _valid)(dbuf));
@@ -792,6 +797,47 @@ GUF_FN_KEYWORDS GUF_CAT(GUF_CNT_NAME, _iter) GUF_CAT(GUF_CNT_NAME, _rend)(const
     };
 }
 
+GUF_FN_KEYWORDS  GUF_CAT(GUF_CNT_NAME, _iter) GUF_CAT(GUF_CNT_NAME, _iter_at_idx)(const GUF_CNT_NAME* dbuf, ptrdiff_t idx)
+{
+    GUF_ASSERT(GUF_CAT(GUF_CNT_NAME, _valid)(dbuf));
+
+    GUF_CAT(GUF_CNT_NAME, _iter) it;
+    it.reverse = false;
+    if (idx < 0 || idx >= dbuf->size || !dbuf->data) {
+        it.ptr = GUF_CAT(GUF_CNT_NAME, _end)(dbuf).ptr;
+    } else {
+        it.ptr = dbuf->data + idx;
+    }
+    return it;
+}
+
+GUF_FN_KEYWORDS  GUF_CAT(GUF_CNT_NAME, _iter) GUF_CAT(GUF_CNT_NAME, _reverse_iter_at_idx)(const GUF_CNT_NAME* dbuf, ptrdiff_t idx)
+{
+    GUF_CAT(GUF_CNT_NAME, _iter) it = GUF_CAT(GUF_CNT_NAME, _iter_at_idx)(dbuf, idx);
+    it.reverse = true;
+    return it;
+}
+
+static const ptrdiff_t GUF_CAT(GUF_CNT_NAME, _npos) = -1;
+
+GUF_FN_KEYWORDS ptrdiff_t GUF_CAT(GUF_CNT_NAME, _iter_to_idx)(const GUF_CNT_NAME* dbuf, GUF_CAT(GUF_CNT_NAME, _iter) it)
+{
+    GUF_ASSERT(GUF_CAT(GUF_CNT_NAME, _valid)(dbuf));
+
+    GUF_CAT(GUF_CNT_NAME, _iter) begin = GUF_CAT(GUF_CNT_NAME, _begin)(dbuf);
+    GUF_CAT(GUF_CNT_NAME, _iter) end = GUF_CAT(GUF_CNT_NAME, _end)(dbuf);
+
+    if (it.ptr == NULL || begin.ptr == NULL || end.ptr == NULL || it.ptr < begin.ptr || it.ptr > end.ptr || !dbuf->data) {
+        return GUF_CAT(GUF_CNT_NAME, _npos);
+    } else if (it.ptr == end.ptr) {
+        return it.reverse ? -1 : dbuf->size;
+    } else {
+        ptrdiff_t idx = it.ptr - begin.ptr;
+        GUF_ASSERT(idx >= 0 && idx <= dbuf->size);
+        return idx;
+    }
+}
+
 GUF_FN_KEYWORDS GUF_CAT(GUF_CNT_NAME, _iter) GUF_CAT(GUF_CNT_NAME, _iter_next)(const GUF_CNT_NAME *dbuf, GUF_CAT(GUF_CNT_NAME, _iter) it, ptrdiff_t step)
 {
     GUF_ASSERT(GUF_CAT(GUF_CNT_NAME, _valid)(dbuf));
@@ -816,18 +862,14 @@ GUF_FN_KEYWORDS GUF_CAT(GUF_CNT_NAME, _iter) GUF_CAT(GUF_CNT_NAME, _iter_next)(c
     } else if (it.ptr == end_ptr && !it.reverse) { // Handle end()
         it_idx = dbuf->size + step;
     } else {
-        GUF_ASSERT_RELEASE(it.ptr >= dbuf->data && it.ptr < end_ptr && (ptrdiff_t)it.ptr - (ptrdiff_t)dbuf->data >= 0)
+        GUF_ASSERT_RELEASE(it.ptr >= dbuf->data && it.ptr < end_ptr)
-        it_idx = (ptrdiff_t)(it.ptr - dbuf->data) + step; // TODO: is this legal?
+        it_idx = (ptrdiff_t)(it.ptr - dbuf->data) + step;
     }
    
-    const ptrdiff_t len = end_ptr && dbuf->data ? end_ptr - dbuf->data : 0;
+    const ptrdiff_t len = (end_ptr && dbuf->data) ? end_ptr - dbuf->data : 0;
     GUF_ASSERT_RELEASE(len >= 0);
 
-    if (len == 0) {
+   if (len == 0 || it_idx >= len || it_idx < 0) {
-        it.ptr = end_ptr;
-    } else if (it_idx >= len) {
-        it.ptr = end_ptr;
-    } else if (it_idx < 0) {
         it.ptr = end_ptr;
     } else {
         GUF_ASSERT(dbuf->data && it.ptr);
@@ -842,8 +884,20 @@ GUF_FN_KEYWORDS GUF_CAT(GUF_CNT_NAME, _iter) GUF_CAT(GUF_CNT_NAME, _find)(GUF_CN
 {
     GUF_ASSERT_RELEASE(GUF_CAT(GUF_CNT_NAME, _valid)(dbuf));
     GUF_ASSERT_RELEASE(needle);
+    GUF_CAT(GUF_CNT_NAME, _iter) dbuf_end = GUF_CAT(GUF_CNT_NAME, _end)(dbuf);
+    dbuf_end.reverse = begin.reverse;
 
-    for (GUF_CAT(GUF_CNT_NAME, _iter) it = begin; it.ptr != end.ptr; it = GUF_CAT(GUF_CNT_NAME, _iter_next)(dbuf, it, 1)) {
+    ptrdiff_t begin_idx = GUF_CAT(GUF_CNT_NAME, _iter_to_idx)(dbuf, begin);
+    ptrdiff_t end_idx = GUF_CAT(GUF_CNT_NAME, _iter_to_idx)(dbuf, end);
+    if (!begin.ptr || !end.ptr || !dbuf->data || begin.ptr == dbuf_end.ptr) {
+        return dbuf_end;
+    } else if (!begin.reverse && begin_idx >= end_idx) {
+        return dbuf_end;
+    } else if (begin.reverse && begin_idx <= end_idx) {
+        return dbuf_end;
+    }
+
+    for (GUF_CAT(GUF_CNT_NAME, _iter) it = begin; it.ptr != end.ptr && it.ptr != dbuf_end.ptr; it = GUF_CAT(GUF_CNT_NAME, _iter_next)(dbuf, it, 1)) {
         #ifdef GUF_T_EQ
             if (GUF_T_EQ(it.ptr, needle)) {
                 return it;
@@ -862,12 +916,22 @@ GUF_FN_KEYWORDS GUF_CAT(GUF_CNT_NAME, _iter) GUF_CAT(GUF_CNT_NAME, _find_val)(GU
     return GUF_CAT(GUF_CNT_NAME, _find)(dbuf, begin, end, &needle_val);
 }
 
-GUF_FN_KEYWORDS GUF_CAT(GUF_CNT_NAME, _iter) GUF_CAT(GUF_CNT_NAME, _find_if)(GUF_CNT_NAME *dbuf, GUF_CAT(GUF_CNT_NAME, _iter) *begin, GUF_CAT(GUF_CNT_NAME, _iter) *end, bool (*predicate)(const GUF_T *)) 
+GUF_FN_KEYWORDS GUF_CAT(GUF_CNT_NAME, _iter) GUF_CAT(GUF_CNT_NAME, _find_if)(GUF_CNT_NAME *dbuf, GUF_CAT(GUF_CNT_NAME, _iter) begin, GUF_CAT(GUF_CNT_NAME, _iter) end, bool (*predicate)(const GUF_T *)) 
 {
     GUF_ASSERT_RELEASE(GUF_CAT(GUF_CNT_NAME, _valid)(dbuf));
-    GUF_ASSERT_RELEASE(begin && end && predicate);
+    GUF_ASSERT_RELEASE(predicate);
 
-    for (GUF_CAT(GUF_CNT_NAME, _iter) it = *begin; it.ptr != end->ptr; GUF_CAT(GUF_CNT_NAME, _iter_next)(dbuf, it, 1)) {
+    GUF_CAT(GUF_CNT_NAME, _iter) dbuf_end = GUF_CAT(GUF_CNT_NAME, _end)(dbuf);
+    dbuf_end.reverse = begin.reverse;
+    if (!begin.ptr || !end.ptr || !dbuf->data) {
+        return dbuf_end;
+    } else if (!begin.reverse && begin.ptr >= end.ptr) {
+        return dbuf_end;
+    } else if (begin.reverse && begin.ptr <= end.ptr) {
+        return dbuf_end;
+    }
+
+    for (GUF_CAT(GUF_CNT_NAME, _iter) it = begin; it.ptr != end.ptr; GUF_CAT(GUF_CNT_NAME, _iter_next)(dbuf, it, 1)) {
         if (predicate(it.ptr)) {
             return it;
         }

src/guf_test.c

@@ -72,12 +72,16 @@ int main(void)
     dbuf_heap_cstr_push(&strings, &move_me, GUF_CPY_MOVE);
     GUF_ASSERT_RELEASE(move_me == NULL);
 
-    char *findme = "Baz 3";
+    dbuf_heap_cstr_push_val_cpy(&strings, "Boz 4");
 
-    dbuf_heap_cstr_iter fnd_it = dbuf_heap_cstr_find(&strings, dbuf_heap_cstr_begin(&strings), dbuf_heap_cstr_end(&strings), &findme);
+    char *findme = "Baz 3";
+    dbuf_heap_cstr_iter beg = dbuf_heap_cstr_rbegin(&strings);
+    dbuf_heap_cstr_iter end = dbuf_heap_cstr_rend(&strings);
+    dbuf_heap_cstr_iter fnd_it = dbuf_heap_cstr_find(&strings, beg, end, &findme);
     if (fnd_it.ptr != dbuf_heap_cstr_end(&strings).ptr) {
-        guf_cstr_heap_free(fnd_it.ptr, NULL);
+        printf("%s found in range [%td, %td) at idx %td\n", findme, dbuf_heap_cstr_iter_to_idx(&strings, beg), dbuf_heap_cstr_iter_to_idx(&strings, end), dbuf_heap_cstr_iter_to_idx(&strings, fnd_it));
-        *fnd_it.ptr = strdup("Found!");
+    } else {
+        printf("%s not found in range [%td, %td) at idx %td\n", findme, dbuf_heap_cstr_iter_to_idx(&strings, beg), dbuf_heap_cstr_iter_to_idx(&strings, end), dbuf_heap_cstr_iter_to_idx(&strings, fnd_it));
     }
 
     GUF_CNT_FOREACH(&strings, dbuf_heap_cstr, it) {
@@ -140,7 +144,7 @@ int main(void)
     }
 
     for (dbuf_int_iter it = dbuf_int_rbegin(&integers); it.ptr != dbuf_int_rend(&integers).ptr; it = dbuf_int_iter_next(&integers, it, 2)) {
-        printf("every other reverse: %d\n", *it.ptr);
+        printf("every other reverse: %d (idx %td)\n", *it.ptr, dbuf_int_iter_to_idx(&integers, it));
     }
 
     dbuf_int_free(&integers, NULL);