Expanded compiler delegate to include callbacks to clear log and to register optional classes.

src/compiler/gravity_parser.c

@@ -2568,6 +2568,18 @@ static void parser_register_optional_classes (gravity_parser_t *parser) {
     gnode_array_push(decls, decl);
     #endif
 
+    // check if optional classes callback is registered
+    if (parser->delegate && parser->delegate->optional_classes) {
+        const char **list = parser->delegate->optional_classes();
+        uint32_t i = 0;
+        while (list[i]) {
+            const char *identifier = list[i];
+            gnode_t *decl = gnode_variable_create(NO_TOKEN, string_dup(identifier), NULL, 0, NULL, LAST_DECLARATION());
+            gnode_array_push(decls, decl);
+            ++i;
+        }
+    }
+    
     // register a variable declaration node in global statements
     gnode_t *node = gnode_variable_decl_create(NO_TOKEN, TOK_KEY_VAR, 0, TOK_KEY_EXTERN, decls, NULL, LAST_DECLARATION());;
     gnode_array_push(parser->statements, (gnode_t *)node);

src/runtime/gravity_core.c

@@ -1582,6 +1582,7 @@ static bool operator_float_cmp (gravity_vm *vm, gravity_value_t *args, uint16_t
     // from https://stackoverflow.com/questions/30808556/float-vs-double-comparison
     // and http://floating-point-gui.de/errors/comparison/
     // check also https://bitbashing.io/comparing-floats.html
+    // the ref should be https://randomascii.wordpress.com/2012/02/25/comparing-floating-point-numbers-2012-edition/
     if (v1.f == 0 || v2.f == 0 || diff < FLOAT_MIN) {
         if (diff < (FLOAT_EPSILON * FLOAT_MIN)) RETURN_VALUE(VALUE_FROM_INT(0), rindex);
     } else {

src/shared/gravity_delegate.h

@@ -33,6 +33,7 @@ typedef struct {
 #define ERROR_DESC_NONE		(error_desc_t){0,0,0,0,NULL}
 
 typedef void				(*gravity_log_callback)	(const char *message, void *xdata);
+typedef void                (*gravity_log_clear) (void *xdata);
 typedef void				(*gravity_error_callback) (error_type_t error_type, const char *description, error_desc_t error_desc, void *xdata);
 typedef void				(*gravity_unittest_callback) (error_type_t error_type, const char *desc, const char *note, gravity_value_t value, int32_t row, int32_t col, void *xdata);
 typedef void				(*gravity_parser_callback) (void *token, void *xdata);
@@ -40,6 +41,7 @@ typedef void                (*gravity_type_callback) (void *token, const char *t
 typedef const char*			(*gravity_precode_callback) (void *xdata);
 typedef const char*			(*gravity_loadfile_callback) (const char *file, size_t *size, uint32_t *fileid, void *xdata);
 typedef const char*			(*gravity_filename_callback) (uint32_t fileid, void *xdata);
+typedef const char**        (*gravity_optclass_callback) (void);
 
 typedef bool				(*gravity_bridge_initinstance) (gravity_vm *vm, void *xdata, gravity_value_t ctx, gravity_instance_t *instance, gravity_value_t args[], int16_t nargs);
 typedef bool				(*gravity_bridge_setvalue) (gravity_vm *vm, void *xdata, gravity_value_t target, const char *key, gravity_value_t value);
@@ -59,6 +61,7 @@ typedef struct {
 
 	// callbacks
 	gravity_log_callback		log_callback;			// log reporting callback
+    gravity_log_clear           log_clear;              // log reset callback
 	gravity_error_callback		error_callback;			// error reporting callback
 	gravity_unittest_callback	unittest_callback;		// special unit test callback
 	gravity_parser_callback		parser_callback;		// lexer callback used for syntax highlight
@@ -66,6 +69,7 @@ typedef struct {
 	gravity_precode_callback	precode_callback;		// called at parse time in order to give the opportunity to add custom source code
 	gravity_loadfile_callback	loadfile_callback;		// callback to give the opportunity to load a file from an import statement
 	gravity_filename_callback	filename_callback;		// called while reporting an error in order to be able to convert a fileid to a real filename
+    gravity_optclass_callback   optional_classes;       // optional classes to be exposed to the semantic checher as extern (to be later registered)
 
 	// bridge
 	gravity_bridge_initinstance	bridge_initinstance;	// init class