3 files changed, 116 insertions, 12 deletions

diff --git a/source/kit/input_buffer.c b/source/kit/input_buffer.c
index b9f280b..8ac7755 100644
--- a/source/kit/input_buffer.c
+++ b/source/kit/input_buffer.c
@@ -98,23 +98,72 @@ kit_ib_handle_t kit_ib_wrap(kit_is_handle_t upstream,
 kit_ib_handle_t kit_ib_read(kit_ib_handle_t buf, ptrdiff_t size) {
   kit_ib_handle_t next;
   memset(&next, 0, sizeof next);
+
   if (buf.status != KIT_OK) {
     next.status = buf.status;
-  } else {
-    buf_acquire(buf.internal);
-    buf_adjust(buf.internal, buf.offset + size);
-    DA_INIT(next.data, size, buf_alloc(buf.internal));
-    if (next.data.size != size)
-      next.status = KIT_ERROR_BAD_ALLOC;
-    kit_out_str_t destination = { .size   = next.data.size,
+    return next;
+  }
+
+  buf_acquire(buf.internal);
+  buf_adjust(buf.internal, buf.offset + size);
+
+  DA_INIT(next.data, size, buf_alloc(buf.internal));
+  if (next.data.size != size)
+    next.status = KIT_ERROR_BAD_ALLOC;
+
+  kit_out_str_t   destination = { .size   = next.data.size,
                                   .values = next.data.values };
-    ptrdiff_t     n = buf_read(buf.internal, buf.offset, destination);
-    next.offset     = buf.offset + n;
-    next.internal   = buf.internal;
-    DA_RESIZE(next.data, n);
-    if (next.data.size != n)
+  ptrdiff_t const n = buf_read(buf.internal, buf.offset, destination);
+  next.offset       = buf.offset + n;
+  next.internal     = buf.internal;
+
+  DA_RESIZE(next.data, n);
+  if (next.data.size != n)
+    next.status = KIT_ERROR_BAD_ALLOC;
+
+  return next;
+}
+
+kit_ib_handle_t kit_ib_read_while(
+    kit_ib_handle_t buf, kit_ib_read_condition_fn condition) {
+  kit_ib_handle_t next;
+  memset(&next, 0, sizeof next);
+
+  if (buf.status != KIT_OK) {
+    next.status = buf.status;
+    return next;
+  }
+
+  buf_acquire(buf.internal);
+
+  DA_INIT(next.data, 0, buf_alloc(buf.internal));
+
+  ptrdiff_t size = 0;
+
+  for (;; ++size) {
+    buf_adjust(buf.internal, buf.offset + size + 1);
+
+    DA_RESIZE(next.data, size + 1);
+    if (next.data.size != size + 1)
       next.status = KIT_ERROR_BAD_ALLOC;
+
+    kit_out_str_t   destination = { .size   = 1,
+                                    .values = next.data.values + size };
+    ptrdiff_t const n = buf_read(buf.internal, buf.offset + size,
+                                 destination);
+
+    kit_str_t data = { .size = size + 1, .values = next.data.values };
+    if (n != 1 || condition == NULL || condition(data) == 0)
+      break;
   }
+
+  next.offset   = buf.offset + size;
+  next.internal = buf.internal;
+
+  DA_RESIZE(next.data, size);
+  if (next.data.size != size)
+    next.status = KIT_ERROR_BAD_ALLOC;
+
   return next;
 }
 
diff --git a/source/kit/input_buffer.h b/source/kit/input_buffer.h
index 1b4329f..60b4872 100644
--- a/source/kit/input_buffer.h
+++ b/source/kit/input_buffer.h
@@ -21,6 +21,11 @@ kit_ib_handle_t kit_ib_wrap(kit_is_handle_t upstream,
 
 kit_ib_handle_t kit_ib_read(kit_ib_handle_t buf, ptrdiff_t size);
 
+typedef int (*kit_ib_read_condition_fn)(kit_str_t data);
+
+kit_ib_handle_t kit_ib_read_while(kit_ib_handle_t          buf,
+                                  kit_ib_read_condition_fn condition);
+
 void kit_ib_destroy(kit_ib_handle_t buf);
 
 #define KIT_IB_WRAP(upstream) \
@@ -28,8 +33,10 @@ void kit_ib_destroy(kit_ib_handle_t buf);
 
 #ifndef KIT_DISABLE_SHORT_NAMES
 #  define ib_handle_t kit_ib_handle_t
+#  define ib_read_condition_fn kit_ib_read_condition_fn
 #  define ib_wrap kit_ib_wrap
 #  define ib_read kit_ib_read
+#  define ib_read_while kit_ib_read_while
 #  define ib_destroy kit_ib_destroy
 
 #  define IB_WRAP KIT_IB_WRAP
diff --git a/source/test/unittests/input_buffer.test.c b/source/test/unittests/input_buffer.test.c
index f1b3738..c062052 100644
--- a/source/test/unittests/input_buffer.test.c
+++ b/source/test/unittests/input_buffer.test.c
@@ -55,3 +55,51 @@ TEST("input buffer read twice") {
   ib_destroy(first);
   is_destroy(in);
 }
+
+static int is_integer_(str_t const data) {
+  for (ptrdiff_t i = 0; i < data.size; i++)
+    if (data.values[i] < '0' || data.values[i] > '9')
+      return 0;
+  return 1;
+}
+
+TEST("input buffer read integer once") {
+  str_t       text  = { .size = 9, .values = "31415 foo" };
+  str_t       num   = { .size = 5, .values = "31415" };
+  is_handle_t in    = IS_WRAP_STRING(text);
+  ib_handle_t first = IB_WRAP(in);
+
+  ib_handle_t second = ib_read_while(first, is_integer_);
+
+  REQUIRE(second.status == KIT_OK);
+  REQUIRE(second.data.size == 5);
+  REQUIRE(AR_EQUAL(num, second.data));
+
+  ib_destroy(second);
+  ib_destroy(first);
+  is_destroy(in);
+}
+
+TEST("input buffer read integer twice") {
+  str_t       text  = { .size = 6, .values = "314 15" };
+  str_t       num_0 = { .size = 3, .values = "314" };
+  str_t       num_1 = { .size = 2, .values = "15" };
+  is_handle_t in    = IS_WRAP_STRING(text);
+  ib_handle_t first = IB_WRAP(in);
+
+  ib_handle_t second = ib_read_while(first, is_integer_);
+  ib_handle_t third  = ib_read(second, 1);
+  ib_handle_t fourth = ib_read_while(third, is_integer_);
+
+  REQUIRE(fourth.status == KIT_OK);
+  REQUIRE(second.data.size == 3);
+  REQUIRE(fourth.data.size == 2);
+  REQUIRE(AR_EQUAL(num_0, second.data));
+  REQUIRE(AR_EQUAL(num_1, fourth.data));
+
+  ib_destroy(first);
+  ib_destroy(second);
+  ib_destroy(third);
+  ib_destroy(fourth);
+  is_destroy(in);
+}