change iteration more ideomatic (#156)

src/bindings/java/omega_edit_wrap.cxx

@@ -1782,6 +1782,34 @@ SWIGEXPORT jlong JNICALL Java_omega_1editJNI_omega_1visit_1change_1create_1conte
 }
 
 
+SWIGEXPORT jint JNICALL Java_omega_1editJNI_omega_1visit_1change_1at_1end(JNIEnv *jenv, jclass jcls, jlong jarg1) {
+  jint jresult = 0 ;
+  omega_visit_change_context_t *arg1 = (omega_visit_change_context_t *) 0 ;
+  int result;
+
+  (void)jenv;
+  (void)jcls;
+  arg1 = *(omega_visit_change_context_t **)&jarg1; 
+  result = (int)omega_visit_change_at_end((omega_visit_change_context_struct const *)arg1);
+  jresult = (jint)result; 
+  return jresult;
+}
+
+
+SWIGEXPORT jint JNICALL Java_omega_1editJNI_omega_1visit_1change_1begin(JNIEnv *jenv, jclass jcls, jlong jarg1) {
+  jint jresult = 0 ;
+  omega_visit_change_context_t *arg1 = (omega_visit_change_context_t *) 0 ;
+  int result;
+
+  (void)jenv;
+  (void)jcls;
+  arg1 = *(omega_visit_change_context_t **)&jarg1; 
+  result = (int)omega_visit_change_begin(arg1);
+  jresult = (jint)result; 
+  return jresult;
+}
+
+
 SWIGEXPORT jint JNICALL Java_omega_1editJNI_omega_1visit_1change_1next(JNIEnv *jenv, jclass jcls, jlong jarg1) {
   jint jresult = 0 ;
   omega_visit_change_context_t *arg1 = (omega_visit_change_context_t *) 0 ;

src/bindings/node/omega_edit_wrap.cxx

@@ -4967,6 +4967,62 @@ static SwigV8ReturnValue _wrap_omega_visit_change_create_context(const SwigV8Arg
 }
 
 
+static SwigV8ReturnValue _wrap_omega_visit_change_at_end(const SwigV8Arguments &args) {
+  SWIGV8_HANDLESCOPE();
+
+  SWIGV8_VALUE jsresult;
+  omega_visit_change_context_t *arg1 = (omega_visit_change_context_t *) 0 ;
+  void *argp1 = 0 ;
+  int res1 = 0 ;
+  int result;
+
+  if(args.Length() != 1) SWIG_exception_fail(SWIG_ERROR, "Illegal number of arguments for _wrap_omega_visit_change_at_end.");
+
+  res1 = SWIG_ConvertPtr(args[0], &argp1,SWIGTYPE_p_omega_visit_change_context_struct, 0 |  0 );
+  if (!SWIG_IsOK(res1)) {
+    SWIG_exception_fail(SWIG_ArgError(res1), "in method '" "omega_visit_change_at_end" "', argument " "1"" of type '" "omega_visit_change_context_t const *""'"); 
+  }
+  arg1 = reinterpret_cast< omega_visit_change_context_t * >(argp1);
+  result = (int)omega_visit_change_at_end((omega_visit_change_context_struct const *)arg1);
+  jsresult = SWIG_From_int(static_cast< int >(result));
+
+
+  SWIGV8_RETURN(jsresult);
+
+  goto fail;
+fail:
+  SWIGV8_RETURN(SWIGV8_UNDEFINED());
+}
+
+
+static SwigV8ReturnValue _wrap_omega_visit_change_begin(const SwigV8Arguments &args) {
+  SWIGV8_HANDLESCOPE();
+
+  SWIGV8_VALUE jsresult;
+  omega_visit_change_context_t *arg1 = (omega_visit_change_context_t *) 0 ;
+  void *argp1 = 0 ;
+  int res1 = 0 ;
+  int result;
+
+  if(args.Length() != 1) SWIG_exception_fail(SWIG_ERROR, "Illegal number of arguments for _wrap_omega_visit_change_begin.");
+
+  res1 = SWIG_ConvertPtr(args[0], &argp1,SWIGTYPE_p_omega_visit_change_context_struct, 0 |  0 );
+  if (!SWIG_IsOK(res1)) {
+    SWIG_exception_fail(SWIG_ArgError(res1), "in method '" "omega_visit_change_begin" "', argument " "1"" of type '" "omega_visit_change_context_t *""'"); 
+  }
+  arg1 = reinterpret_cast< omega_visit_change_context_t * >(argp1);
+  result = (int)omega_visit_change_begin(arg1);
+  jsresult = SWIG_From_int(static_cast< int >(result));
+
+
+  SWIGV8_RETURN(jsresult);
+
+  goto fail;
+fail:
+  SWIGV8_RETURN(SWIGV8_UNDEFINED());
+}
+
+
 static SwigV8ReturnValue _wrap_omega_visit_change_next(const SwigV8Arguments &args) {
   SWIGV8_HANDLESCOPE();
 
@@ -5561,6 +5617,8 @@ SWIGV8_AddStaticFunction(exports_obj, "omega_viewport_notify", _wrap_omega_viewp
 SWIGV8_AddStaticFunction(exports_obj, "omega_visit_changes", _wrap_omega_visit_changes, context);
 SWIGV8_AddStaticFunction(exports_obj, "omega_visit_changes_reverse", _wrap_omega_visit_changes_reverse, context);
 SWIGV8_AddStaticFunction(exports_obj, "omega_visit_change_create_context", _wrap_omega_visit_change_create_context, context);
+SWIGV8_AddStaticFunction(exports_obj, "omega_visit_change_at_end", _wrap_omega_visit_change_at_end, context);
+SWIGV8_AddStaticFunction(exports_obj, "omega_visit_change_begin", _wrap_omega_visit_change_begin, context);
 SWIGV8_AddStaticFunction(exports_obj, "omega_visit_change_next", _wrap_omega_visit_change_next, context);
 SWIGV8_AddStaticFunction(exports_obj, "omega_visit_change_context_get_change", _wrap_omega_visit_change_context_get_change, context);
 SWIGV8_AddStaticFunction(exports_obj, "omega_visit_change_destroy_context", _wrap_omega_visit_change_destroy_context, context);

src/include/omega_edit/visit.h

@@ -61,6 +61,20 @@ typedef struct omega_visit_change_context_struct omega_visit_change_context_t;
  */
 omega_visit_change_context_t *omega_visit_change_create_context(const omega_session_t *session_ptr, int reverse);
 
+/**
+ * Return non-zero if we are at the end of the change visitations
+ * @param change_context_ptr change visitor context to see if we're at the end of
+ * @return non-zero if we are at the end of the change visitations and zero if there are changes remaining to visit
+ */
+int omega_visit_change_at_end(const omega_visit_change_context_t *change_context_ptr);
+
+/**
+ * Set the change visitor context to the beginning of the changes
+ * @param change_context_ptr change visitor context to set to the beginning
+ * @return non-zero if there are no changes to visit and zero otherwise
+ */
+int omega_visit_change_begin(omega_visit_change_context_t *change_context_ptr);
+
 /**
  * Given a change visitor context, find the next change
  * @param change_context_ptr change visitor context to find the next change in

src/lib/visit.cpp

@@ -40,6 +40,7 @@ int omega_visit_changes_reverse(const omega_session_t *session_ptr, omega_sessio
 struct omega_visit_change_context_struct {
     const omega_session_t *session_ptr{};
     const omega_change_t *change_ptr{};
+    bool at_end;
     bool reverse{};
     union {
         omega_changes_t::const_iterator *iter_ptr;
@@ -56,10 +57,16 @@ omega_visit_change_context_t *omega_visit_change_create_context(const omega_sess
     change_context_ptr->change_ptr = nullptr;
     change_context_ptr->reverse = (0 != reverse);
     change_context_ptr->change_iter.iter_ptr = nullptr;
+    change_context_ptr->at_end = true;
     return change_context_ptr;
 }
 
-int omega_visit_change_next(omega_visit_change_context_t *change_context_ptr) {
+int omega_visit_change_at_end(const omega_visit_change_context_t *change_context_ptr) {
+    assert(change_context_ptr);
+    return (change_context_ptr->at_end) ? 1 : 0;
+}
+
+int omega_visit_change_begin(omega_visit_change_context_t *change_context_ptr) {
     assert(change_context_ptr);
     assert(change_context_ptr->session_ptr);
     assert(change_context_ptr->session_ptr->models_.back());
@@ -68,27 +75,39 @@ int omega_visit_change_next(omega_visit_change_context_t *change_context_ptr) {
         if (!change_context_ptr->change_iter.riter_ptr) {
             change_context_ptr->change_iter.riter_ptr = new omega_changes_t::const_reverse_iterator;
             assert(change_context_ptr->change_iter.riter_ptr);
-            *change_context_ptr->change_iter.riter_ptr =
-                    change_context_ptr->session_ptr->models_.back()->changes.rbegin();
-        } else {
-            ++*change_context_ptr->change_iter.riter_ptr;
         }
-        return (*change_context_ptr->change_iter.riter_ptr ==
-                change_context_ptr->session_ptr->models_.back()->changes.rend())
-                       ? 0
-                       : 1;
-    }
-    if (!change_context_ptr->change_iter.iter_ptr) {
-        change_context_ptr->change_iter.iter_ptr = new omega_changes_t::const_iterator;
-        assert(change_context_ptr->change_iter.iter_ptr);
+        *change_context_ptr->change_iter.riter_ptr = change_context_ptr->session_ptr->models_.back()->changes.rbegin();
+        change_context_ptr->at_end = (*change_context_ptr->change_iter.riter_ptr ==
+                                        change_context_ptr->session_ptr->models_.back()->changes.rend());
+    } else {
+        if (!change_context_ptr->change_iter.iter_ptr) {
+            change_context_ptr->change_iter.iter_ptr = new omega_changes_t::const_iterator;
+            assert(change_context_ptr->change_iter.iter_ptr);
+        }
         *change_context_ptr->change_iter.iter_ptr = change_context_ptr->session_ptr->models_.back()->changes.cbegin();
+        change_context_ptr->at_end = (*change_context_ptr->change_iter.iter_ptr ==
+                                        change_context_ptr->session_ptr->models_.back()->changes.cend());
+    }
+    return omega_visit_change_at_end(change_context_ptr);
+}
+
+int omega_visit_change_next(omega_visit_change_context_t *change_context_ptr) {
+    assert(change_context_ptr);
+    assert(change_context_ptr->session_ptr);
+    assert(change_context_ptr->session_ptr->models_.back());
+    if (change_context_ptr->session_ptr->models_.back()->changes.empty()) { return 0; }
+    if (change_context_ptr->reverse) {
+        assert(change_context_ptr->change_iter.riter_ptr);
+        ++*change_context_ptr->change_iter.riter_ptr;
+        change_context_ptr->at_end = (*change_context_ptr->change_iter.riter_ptr ==
+                                        change_context_ptr->session_ptr->models_.back()->changes.rend());
     } else {
+        assert(change_context_ptr->change_iter.iter_ptr);
         ++*change_context_ptr->change_iter.iter_ptr;
+        change_context_ptr->at_end = (*change_context_ptr->change_iter.iter_ptr ==
+                                        change_context_ptr->session_ptr->models_.back()->changes.cend());
     }
-    return (*change_context_ptr->change_iter.iter_ptr ==
-            change_context_ptr->session_ptr->models_.back()->changes.cend())
-                   ? 0
-                   : 1;
+    return omega_visit_change_at_end(change_context_ptr);
 }
 
 const omega_change_t *omega_visit_change_context_get_change(const omega_visit_change_context_t *change_context_ptr) {

src/tests/omega_test.cpp

@@ -101,7 +101,7 @@ TEST_CASE("File Compare", "[UtilTests]") {
 
 TEST_CASE("End Of Line", "[EOLTests]") {
     omega_byte_t buffer[1024];
-    FILE * in_fp = fopen("data/test1.dat", "rb");
+    FILE *in_fp = fopen("data/test1.dat", "rb");
     REQUIRE(in_fp);
     REQUIRE(0 == fseek(in_fp, 0, SEEK_END));
     auto file_size = ftell(in_fp);
@@ -110,7 +110,7 @@ TEST_CASE("End Of Line", "[EOLTests]") {
     REQUIRE(file_size < sizeof(buffer));
     REQUIRE(file_size == fread(buffer, sizeof(omega_byte_t), file_size, in_fp));
     REQUIRE(0 == fclose(in_fp));
-    FILE * out_fp = fopen("data/test1.actual.eol.1.dat", "wb");
+    FILE *out_fp = fopen("data/test1.actual.eol.1.dat", "wb");
     REQUIRE(out_fp);
     REQUIRE(file_size == fwrite(buffer, sizeof(omega_byte_t), file_size, out_fp));
     REQUIRE(file_size == ftell(out_fp));
@@ -272,14 +272,14 @@ TEST_CASE("Transformer", "[TransformerTest]") {
 }
 
 TEST_CASE("File Transformer", "[TransformerTest]") {
-    REQUIRE(0 == omega_util_apply_byte_transform_to_file("data/test1.dat", "data/test1.actual.transformed.1.dat", to_upper, nullptr, 0,
-                                            0));
+    REQUIRE(0 == omega_util_apply_byte_transform_to_file("data/test1.dat", "data/test1.actual.transformed.1.dat",
+                                                         to_upper, nullptr, 0, 0));
     REQUIRE(0 == compare_files("data/test1.expected.transformed.1.dat", "data/test1.actual.transformed.1.dat"));
-    REQUIRE(0 == omega_util_apply_byte_transform_to_file("data/test1.dat", "data/test1.actual.transformed.2.dat", to_lower, nullptr, 37,
-                                            10));
+    REQUIRE(0 == omega_util_apply_byte_transform_to_file("data/test1.dat", "data/test1.actual.transformed.2.dat",
+                                                         to_lower, nullptr, 37, 10));
     REQUIRE(0 == compare_files("data/test1.expected.transformed.2.dat", "data/test1.actual.transformed.2.dat"));
-    REQUIRE(0 != omega_util_apply_byte_transform_to_file("data/test1.dat", "data/test1.actual.transformed.3.dat", to_lower, nullptr, 37,
-                                            100));
+    REQUIRE(0 != omega_util_apply_byte_transform_to_file("data/test1.dat", "data/test1.actual.transformed.3.dat",
+                                                         to_lower, nullptr, 37, 100));
     REQUIRE(0 == omega_util_file_exists("data/test1.actual.transformed.3.dat"));
 }
 
@@ -300,7 +300,8 @@ typedef struct file_info_struct {
     size_t num_changes{};
 } file_info_t;
 
-static inline void session_change_cbk(const omega_session_t *session_ptr, omega_session_event_t session_event, const omega_change_t *change_ptr) {
+static inline void session_change_cbk(const omega_session_t *session_ptr, omega_session_event_t session_event,
+                                      const omega_change_t *change_ptr) {
     // Not all session changes are the result of a standard change like delete / insert / overwrite
     switch (session_event) {
         case SESSION_EVT_EDIT:
@@ -361,7 +362,7 @@ typedef struct mask_info_struct {
     omega_mask_kind_t mask_kind;
 } mask_info_t;
 
-static inline omega_byte_t byte_mask_transform(omega_byte_t byte, void * user_data_ptr) {
+static inline omega_byte_t byte_mask_transform(omega_byte_t byte, void *user_data_ptr) {
     const auto mask_info_ptr = reinterpret_cast<mask_info_t *>(user_data_ptr);
     return omega_util_mask_byte(byte, mask_info_ptr->mask, mask_info_ptr->mask_kind);
 }
@@ -374,7 +375,8 @@ TEST_CASE("Checkpoint Tests", "[CheckpointTests]") {
     REQUIRE(session_ptr);
     auto file_size = omega_session_get_computed_file_size(session_ptr);
     REQUIRE(file_size > 0);
-    REQUIRE(0 != omega_edit_insert_string(session_ptr, 0, "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+    REQUIRE(0 !=
+            omega_edit_insert_string(session_ptr, 0, "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
     REQUIRE(0 == omega_session_get_num_checkpoints(session_ptr));
     REQUIRE(-1 == omega_edit_destroy_last_checkpoint(session_ptr));
     REQUIRE(0 == omega_edit_apply_transform(session_ptr, to_lower, nullptr, 0, 0, "./data"));
@@ -406,7 +408,8 @@ TEST_CASE("Checkpoint Tests", "[CheckpointTests]") {
     mask_info.mask_kind = MASK_AND;
     REQUIRE(0 == omega_edit_apply_transform(session_ptr, byte_mask_transform, &mask_info, 10, 0, "./data"));
     REQUIRE(6 == omega_session_get_num_checkpoints(session_ptr));
-    REQUIRE(0 != omega_edit_overwrite_string(session_ptr, 0, "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+    REQUIRE(0 != omega_edit_overwrite_string(session_ptr, 0,
+                                             "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
     REQUIRE(0 == omega_edit_save(session_ptr, "data/test1.actual.checkpoint.6.dat", 1, nullptr));
     REQUIRE(0 == compare_files("data/test1.expected.checkpoint.6.dat", "data/test1.actual.checkpoint.6.dat"));
     REQUIRE(0 == omega_edit_destroy_last_checkpoint(session_ptr));
@@ -617,7 +620,8 @@ TEST_CASE("Check initialization", "[InitTests]") {
             auto visit_change_context = omega_visit_change_create_context(session_ptr, 0);
             REQUIRE(visit_change_context);
             string forward_change_sequence;
-            while (omega_visit_change_next(visit_change_context)) {
+            for (omega_visit_change_begin(visit_change_context); !omega_visit_change_at_end(visit_change_context);
+                 omega_visit_change_next(visit_change_context)) {
                 change_ptr = omega_visit_change_context_get_change(visit_change_context);
                 forward_change_sequence += omega_change_get_kind_as_char(change_ptr);
             }
@@ -628,7 +632,8 @@ TEST_CASE("Check initialization", "[InitTests]") {
             auto reverse_change_sequence = forward_change_sequence;
             std::reverse(reverse_change_sequence.begin(), reverse_change_sequence.end());
             string change_sequence;
-            while (omega_visit_change_next(visit_change_context)) {
+            for (omega_visit_change_begin(visit_change_context); !omega_visit_change_at_end(visit_change_context);
+                 omega_visit_change_next(visit_change_context)) {
                 change_ptr = omega_visit_change_context_get_change(visit_change_context);
                 change_sequence += omega_change_get_kind_as_char(change_ptr);
             }
@@ -662,7 +667,8 @@ struct view_mode_t {
     display_mode_t display_mode = display_mode_t::CHAR_MODE;
 };
 
-static inline void vpt_change_cbk(const omega_viewport_t *viewport_ptr, omega_viewport_event_t viewport_event, const omega_change_t *change_ptr) {
+static inline void vpt_change_cbk(const omega_viewport_t *viewport_ptr, omega_viewport_event_t viewport_event,
+                                  const omega_change_t *change_ptr) {
     if (change_ptr) { clog << "Change serial: " << omega_change_get_serial(change_ptr) << endl; }
     clog << dec << "capacity: " << omega_viewport_get_capacity(viewport_ptr)
          << " length: " << omega_viewport_get_length(viewport_ptr)