+added a duplicate sub routine error handling; +added optional argument support for INPUT statement; *fixed a variable multiple freeing bug in sub routine; *polished document.

HISTORY

@@ -1,7 +1,14 @@
+Sep. 11 2015
+Added a duplicate sub routine error handling
+Added optional argument support for INPUT statement
+Fixed a variable multiple freeing bug in sub routine
+Polished document
+
 Sep. 8 2015
 Fixed a type parsing of sub routine bug
 Fixed a scope processing bug
 Fixed a sub routine invoking bug without leading CALL statement or result receiver
+Added a makefile
 
 Sep. 6 2015
 Improved sub routine
@@ -12,7 +19,7 @@ Prompted more friendly dummy function message
 Polished code and document
 
 Sep. 1 2015
-Added support for user customized routine by DEF/ENDDEF
+Added support for user customized sub routine by DEF/ENDDEF
 
 Aug. 26 2015
 Added a memory pool to interpreter shell in main.c
@@ -56,7 +63,7 @@ Changed mb_dispose_value as public
 
 Apr. 23 2015 Version 1.1
 Added debug APIs
-Added (nestable) multi line IF statement support
+Added (nestable) multiple line IF statement support
 
 Apr. 15 2015
 Added mb_pop_usertype, mb_push_usertype to support user defined type
@@ -102,12 +109,12 @@ Added an mb_remove_reserved_func function which allows a user to disable/remove
 
 May. 22 2014
 Fixed a crash bug when missing colon in a combined line, thanks to Michael P. Welch for pointing it out
-Fixed a missing lexical cursor stepping bug in INPUT function
+Fixed a missing lexical cursor stepping bug in INPUT statement
 
 Mar. 17 2014
 Added an XCode project
 Added a safe stdin reader function mb_gets
-Fixed a crash bug in INPUT function
+Fixed a crash bug in INPUT statement
 
 Feb. 17 2014
 Added mod by zero processing
@@ -119,7 +126,7 @@ Jul. 19 2013
 Fixed a crash bug in _execute_statement, thanks to Jon Mayo for pointing it out
 
 Feb. 25 2013
-Fixed a cross routine multi-statement execution bug, thanks to Bruce Kendall for pointing it out
+Fixed a cross routine multiple statement execution bug, thanks to Bruce Kendall for pointing it out
 Fixed a memory corruption bug when loading a script file
 
 Jan. 9 2013

README.md

@@ -1,18 +1,18 @@
 ![](resource/icon.ico)
 
-Copyright (C) 2011 - 2015 [Wang Renxin](https://twitter.com/wangrenxin)
+Copyright (C) 2011 - 2015 [Wang Renxin](https://twitter.com/wangrenxin). All rights reserved.
 
 [LinkedIn](https://cn.linkedin.com/pub/wang-renxin/43/494/20)
 
-Why are existing script interpreters so complex? Why is it so difficult to integrate with them? Why not try MY-BASIC today!
+Why are existing script interpreters so complex? Why is it so difficult to integrate with them? Why not try MY-BASIC today! Scripting should be simple and enjoyable.
 
 ## Introduction
 
-MY-BASIC is a tiny cross-platform easy extendable BASIC interpreter written in pure C with about 7000 lines of source code. Its grammar is similar to structured BASIC. It is aimed to be either an embeddable scripting language or a standalone interpreter. The core is pretty light; all in a C source file and an associated header file. You can combine MY-BASIC with an existing C, C++, Objective-C, etc. project easily, scripting driven can make your projects more powerful, elegant and neat.
+MY-BASIC is a tiny cross-platform easy extendable BASIC interpreter written in pure C with about 7000 lines of source code. Its grammar is similar to structured BASIC. It is aimed to be either an embeddable scripting language or a standalone interpreter. The core is pretty light; all in a C source file and an associated header file. You are able to easily combine MY-BASIC with an existing project in C, C++, Objective-C, etc. Scripting driven can make your projects more powerful, elegant and neat.
 
 ## Main features
 
-* It is free
+* It is totally free to use MY-BASIC for individual or commercial purpose under the MIT license
 * Written in clean ANSI C, source code portable
 * With most common BASIC syntax
 * Small (within memory usage less than 128KB) and fast
@@ -26,11 +26,23 @@ MY-BASIC is a tiny cross-platform easy extendable BASIC interpreter written in p
 * Standard string functions
 * Debug APIs
 * High expansibility, easy to use APIs, easy to write customized scripting interfaces
-* It's able to use it as a standalone interpreter, or integrate it with existing C, C++, Objective-C, etc. projects
+* It's able to use it as a standalone interpreter, or integrate it with existing projects in C, C++, Objective-C, etc.
 * It's able to learn how to build an interpreter from scratch from MY-BASIC
 * It's able to build your own dialect based on MY-BASIC
 * More features/modules under developing
 
+## Scripting at a glance
+
+Come along with a traditional "hello world" script in MY-BASIC:
+
+	def foo(a, b)
+		print a + " " + b;
+	enddef
+
+	foo("Hello", "world!")
+
+	input
+
 ## [Interpreter workflow diagram](https://github.com/paladin-t/my_basic/wiki/Interpreter-workflow-diagram)
 
 ![](https://github.com/paladin-t/my_basic/blob/master/interpreter%20workflow%20diagram.png)
@@ -57,7 +69,7 @@ You can definitely [link with MY-BASIC as a lib](https://github.com/paladin-t/my
 
 For more details about using MY-BASIC when it's already integrated with exist projects, please see [MY-BASIC Quick Reference](MY-BASIC%20Quick%20Reference.pdf).
 
-## [WIKI](https://github.com/paladin-t/my_basic/wiki)
+## [Wiki](https://github.com/paladin-t/my_basic/wiki)
 
 * [Passes](https://github.com/paladin-t/my_basic/wiki/Passes)
 * [Interpreter workflow diagram](https://github.com/paladin-t/my_basic/wiki/Interpreter-workflow-diagram)

core/my_basic.c

@@ -52,6 +52,7 @@ extern "C" {
 #	pragma warning(push)
 #	pragma warning(disable : 4127)
 #	pragma warning(disable : 4305)
+#	pragma warning(disable : 4996)
 #endif /* _MSC_VER */
 
 #ifdef __APPLE__
@@ -78,7 +79,7 @@ extern "C" {
 /** Macros */
 #define _VER_MAJOR 1
 #define _VER_MINOR 1
-#define _VER_REVISION 68
+#define _VER_REVISION 69
 #define _MB_VERSION ((_VER_MAJOR * 0x01000000) + (_VER_MINOR * 0x00010000) + (_VER_REVISION))
 
 /* Uncomment the line below to treat warning as error */
@@ -211,6 +212,7 @@ static const char* _ERR_DESC[] = {
 	"Don't suspend in a routine",
 	"Don't mix instructional and structured sub routines",
 	"Routine expected",
+	"Duplicate routine",
 	/** Extended abort */
 	"Extended abort"
 };
@@ -365,6 +367,7 @@ typedef struct _parsing_context_t {
 	_object_t* last_symbol;
 	_parsing_state_e parsing_state;
 	_symbol_state_e symbol_state;
+	unsigned short class_state;
 	unsigned short routine_state;
 	unsigned short routine_params_state;
 	int parsing_pos;
@@ -776,7 +779,9 @@ static bool_t _is_array(void* obj);
 static bool_t _is_string(void* obj);
 static char* _extract_string(_object_t* obj);
 
-static void _init_instance(mb_interpreter_t* s, _class_t* instance, char* n);
+static void _init_class(mb_interpreter_t* s, _class_t* instance, char* n);
+static void _begin_class(mb_interpreter_t* s);
+static void _end_class(mb_interpreter_t* s);
 static void _init_routine(mb_interpreter_t* s, _routine_t* routine, char* n);
 static void _begin_routine(mb_interpreter_t* s);
 static void _end_routine(mb_interpreter_t* s);
@@ -843,11 +848,21 @@ static int _close_std_lib(mb_interpreter_t* s);
 
 #ifdef _MSC_VER
 #	if _MSC_VER < 1300
-#		define _do_nothing(__s, __l, __exit, __result) do { static int i = 0; ++i; printf("Unaccessable function called %d times\n", i); mb_unrefvar(__s); mb_unrefvar(__l); mb_unrefvar(__result); goto _exit; } while(0)
+#		define _do_nothing(__s, __l, __exit, __result) \
+			do { \
+				_ls_node_t* ast = 0; static int i = 0; ++i; \
+				printf("Unaccessable function called %d times\n", i); \
+				ast = (_ls_node_t*)(*(__l)); \
+				_handle_error_on_obj((__s), SE_RN_WRONG_FUNCTION_REACHED, 0, DON(ast), MB_FUNC_ERR, __exit, __result); \
+			} while(0)
 #	endif /* _MSC_VER < 1300 */
 #endif /* _MSC_VER */
 #ifndef _do_nothing
-#	define _do_nothing(__s, __l, __exit, __result) do { _ls_node_t* ast = (_ls_node_t*)(*(__l)); _handle_error_on_obj((__s), SE_RN_WRONG_FUNCTION_REACHED, (char*)MB_FUNC, DON(ast), MB_FUNC_ERR, __exit, __result); } while(0);
+#	define _do_nothing(__s, __l, __exit, __result) \
+		do { \
+			_ls_node_t* ast = (_ls_node_t*)(*(__l)); \
+			_handle_error_on_obj((__s), SE_RN_WRONG_FUNCTION_REACHED, (char*)MB_FUNC, DON(ast), MB_FUNC_ERR, __exit, __result); \
+		} while(0);
 #endif /* _do_nothing */
 
 /** Core lib */
@@ -1971,6 +1986,7 @@ int _eval_routine(mb_interpreter_t* s, _ls_node_t** l, _routine_t* r) {
 			_pop_scope(s);
 
 			result = _public_value_to_internal_object(&arg, var->data);
+			var->data->ref = true;
 			if(result != MB_FUNC_OK)
 				goto _exit;
 		}
@@ -2302,9 +2318,15 @@ int _create_symbol(mb_interpreter_t* s, _ls_node_t* l, char* sym, _object_t** ob
 			(*obj)->data.instance = ((_object_t*)(glbsyminscope->data))->data.instance;
 			(*obj)->ref = true;
 			*delsym = true;
+			if(running != (*obj)->data.instance->scope &&
+				context->class_state &&
+				_IS_FUNC(context->last_symbol, _core_class)) {
+				_push_scope(s, (*obj)->data.instance->scope);
+			}
 		} else {
 			tmp.instance = (_class_t*)mb_malloc(sizeof(_class_t));
-			_init_instance(s, tmp.instance, sym);
+			_init_class(s, tmp.instance, sym);
+			_push_scope(s, tmp.instance->scope);
 			(*obj)->data.instance = tmp.instance;
 
 			ul = _ht_set_or_insert(running->var_dict, sym, *obj);
@@ -2492,23 +2514,43 @@ _data_e _get_symbol_type(mb_interpreter_t* s, char* sym, _raw_t* value) {
 		goto _exit;
 	}
 	/* _class_t */
-	if(context->last_symbol && _IS_FUNC(context->last_symbol, _core_class)) {
+	if(context->last_symbol) {
 		glbsyminscope = _search_var_in_scope_chain(s, 0, sym);
-		if(glbsyminscope && ((_object_t*)(glbsyminscope->data))->type == _DT_VAR) {
+		if(glbsyminscope && ((_object_t*)glbsyminscope->data)->type == _DT_CLASS) {
-			tmp.obj = (_object_t*)(glbsyminscope->data);
+			if(_IS_FUNC(context->last_symbol, _core_class))
-			if(!tmp.obj->ref) {
+				_begin_class(s);
-				_ht_remove(running->var_dict, sym, _ls_cmp_extra_string);
+			result = _DT_CLASS;
-				_dispose_object(tmp.obj);
+
-			}
+			goto _exit;
-			tmp.obj->type = _DT_CLASS;
-			tmp.obj->data.instance = (_class_t*)mb_malloc(sizeof(_class_t));
-			_init_instance(s, tmp.obj->data.instance, sym);
-			_ht_set_or_insert(running->var_dict, sym, tmp.obj);
 		}
+		if(_IS_FUNC(context->last_symbol, _core_class)) {
+			if(_IS_FUNC(context->last_symbol, _core_class))
+				_begin_class(s);
+			if(!_is_identifier_char(sym[0])) {
+				result = _DT_NIL;
 
-		result = _DT_CLASS;
+				goto _exit;
+			}
+			if(glbsyminscope && ((_object_t*)(glbsyminscope->data))->type == _DT_VAR) {
+				tmp.obj = (_object_t*)(glbsyminscope->data);
+				if(!tmp.obj->ref) {
+					_ht_remove(running->var_dict, sym, _ls_cmp_extra_string);
+					_dispose_object(tmp.obj);
+				}
+				tmp.obj->type = _DT_CLASS;
+				tmp.obj->data.instance = (_class_t*)mb_malloc(sizeof(_class_t));
+				_init_class(s, tmp.obj->data.instance, sym);
+				_init_class(s, tmp.obj->data.instance, sym);
+				_ht_set_or_insert(running->var_dict, sym, tmp.obj);
+			}
 
-		goto _exit;
+			result = _DT_CLASS;
+
+			goto _exit;
+		} else if(_IS_FUNC(context->last_symbol, _core_endclass)) {
+			_end_class(s);
+			_pop_scope(s);
+		}
 	}
 	/* _routine_t */
 	if(context->last_symbol) {
@@ -3108,14 +3150,39 @@ char* _extract_string(_object_t* obj) {
 	return result;
 }
 
-void _init_instance(mb_interpreter_t* s, _class_t* instance, char* n) {
+void _init_class(mb_interpreter_t* s, _class_t* instance, char* n) {
 	/* Initialize an instance */
+	_running_context_t* running = 0;
+
 	mb_assert(s && instance && n);
 
+	running = s->running_context;
+
 	memset(instance, 0, sizeof(_class_t));
 	instance->name = n;
 	instance->scope = (_running_context_t*)mb_malloc(sizeof(_running_context_t));
 	memset(instance->scope, 0, sizeof(_running_context_t));
+	instance->scope->var_dict = _ht_create(0, _ht_cmp_string, _ht_hash_string, 0);
+}
+
+void _begin_class(mb_interpreter_t* s) {
+	/* Begin parsing a class */
+	_parsing_context_t* context = 0;
+
+	mb_assert(s);
+
+	context = s->parsing_context;
+	context->class_state++;
+}
+
+void _end_class(mb_interpreter_t* s) {
+	/* End parsing a class */
+	_parsing_context_t* context = 0;
+
+	mb_assert(s);
+
+	context = s->parsing_context;
+	context->class_state--;
 }
 
 void _init_routine(mb_interpreter_t* s, _routine_t* routine, char* n) {
@@ -3279,6 +3346,16 @@ int _dispose_object(_object_t* obj) {
 			safe_free(obj->data.label);
 		}
 
+		break;
+	case _DT_CLASS:
+		if(!obj->ref) {
+			safe_free(obj->data.instance->name);
+			_ht_foreach(obj->data.instance->scope->var_dict, _destroy_object);
+			_ht_destroy(obj->data.instance->scope->var_dict);
+			safe_free(obj->data.instance->scope);
+			safe_free(obj->data.instance);
+		}
+
 		break;
 	case _DT_ROUTINE:
 		if(!obj->ref) {
@@ -3291,13 +3368,6 @@ int _dispose_object(_object_t* obj) {
 			safe_free(obj->data.routine);
 		}
 
-		break;
-	case _DT_CLASS:
-		if(!obj->ref) {
-			safe_free(obj->data.instance->scope);
-			safe_free(obj->data.instance);
-		}
-
 		break;
 	case _DT_NIL: /* Fall through */
 	case _DT_ANY: /* Fall through */
@@ -3599,6 +3669,10 @@ int _execute_statement(mb_interpreter_t* s, _ls_node_t** l) {
 	case _DT_STRING:
 		_handle_error_on_obj(s, SE_RN_INVALID_EXPRESSION, 0, DON(ast), MB_FUNC_ERR, _exit, result);
 
+		break;
+	case _DT_CLASS:
+		mb_assert(0 && "Not implemented");
+
 		break;
 	case _DT_ROUTINE:
 		ast = ast->prev;
@@ -6161,6 +6235,7 @@ int _core_def(mb_interpreter_t* s, void** l) {
 	/* DEF statement */
 	int result = MB_FUNC_OK;
 	_ls_node_t* ast = 0;
+	_running_context_t* running = 0;
 	_object_t* obj = 0;
 	_var_t* var = 0;
 	_ls_node_t*  rnode = 0;
@@ -6168,6 +6243,8 @@ int _core_def(mb_interpreter_t* s, void** l) {
 
 	mb_assert(s && l);
 
+	running = s->running_context;
+
 	ast = (_ls_node_t*)(*l);
 	ast = ast->next;
 
@@ -6177,6 +6254,9 @@ int _core_def(mb_interpreter_t* s, void** l) {
 	if(!_IS_ROUTINE(obj)) {
 		_handle_error_on_obj(s, SE_RN_ROUTINE_EXPECTED, 0, DON(ast), MB_FUNC_ERR, _exit, result);
 	}
+	if(obj->data.routine->entry) {
+		_handle_error_on_obj(s, SE_RN_DUPLICATE_ROUTINE, 0, DON(ast), MB_FUNC_ERR, _exit, result);
+	}
 	routine = (_routine_t*)(((_object_t*)(ast->data))->data.routine);
 	ast = ast->next;
 	obj = (_object_t*)(ast->data);
@@ -6233,17 +6313,32 @@ _exit:
 }
 
 int _core_class(mb_interpreter_t* s, void** l) {
-	/* OBJ statement */
+	/* CLASS statement */
 	int result = MB_FUNC_OK;
+	_ls_node_t* ast = 0;
+	_running_context_t* running = 0;
 
-	_do_nothing(s, l, _exit, result);
+	mb_assert(s && l);
+
+	running = s->running_context;
+
+	ast = (_ls_node_t*)(*l);
+	ast = ast->next;
+
+	_using_jump_set_of_structured(s, ast, _exit, result);
+
+	_skip_to(s, &ast, _core_endclass, _DT_NIL);
+
+	ast = ast->next;
 
 _exit:
+	*l = ast;
+
 	return result;
 }
 
 int _core_endclass(mb_interpreter_t* s, void** l) {
-	/* ENDOBJ statement */
+	/* ENDCLASS statement */
 	int result = MB_FUNC_OK;
 
 	_do_nothing(s, l, _exit, result);
@@ -7132,7 +7227,12 @@ int _std_input(mb_interpreter_t* s, void** l) {
 	ast = (_ls_node_t*)(*l);
 	obj = (_object_t*)(ast->data);
 
-	if(!obj || obj->type != _DT_VAR) {
+	if(!obj || obj->type == _DT_EOS) {
+		_get_inputer(s)(line, sizeof(line));
+
+		goto _exit;
+	}
+	if(obj->type != _DT_VAR) {
 		_handle_error_on_obj(s, SE_RN_VARIABLE_EXPECTED, 0, DON(ast), MB_FUNC_ERR, _exit, result);
 	}
 	if(obj->data.variable->data->type == _DT_INT || obj->data.variable->data->type == _DT_REAL) {

core/my_basic.h

@@ -219,6 +219,7 @@ typedef enum mb_error_e {
 	SE_RN_DONT_SUSPEND_IN_A_ROUTINE,
 	SE_RN_DONT_MIX_INSTRUCTIONAL_AND_STRUCTURED,
 	SE_RN_ROUTINE_EXPECTED,
+	SE_RN_DUPLICATE_ROUTINE,
 	/** Extended abort */
 	SE_EA_EXTENDED_ABORT,
 	/** Extra */

makefile

@@ -5,7 +5,7 @@ main.o : shell/main.c core/my_basic.h
 	cc -Os -c shell/main.c
 
 my_basic.o : core/my_basic.c core/my_basic.h
-	cc -Os -c core/my_basic.c
+	cc -Os -c core/my_basic.c -Wno-multichar -Wno-overflow
 
 clean :
-	rm edit $(objects)
+	rm -f main.o my_basic.o output/my_basic_bin output/my_basic_bin.exe

resource/my_basic.rc

@@ -36,8 +36,8 @@
 	IDI_ICON_MAIN ICON "icon.ico"
 
 	VS_VERSION_INFO VERSIONINFO
-	FILEVERSION 1,1,68,0
+	FILEVERSION 1,1,69,0
-	PRODUCTVERSION 1,1,68,0
+	PRODUCTVERSION 1,1,69,0
 	FILEFLAGSMASK 0x17L
 #	ifdef _DEBUG
 	FILEFLAGS 0x1L
@@ -55,13 +55,13 @@
 				VALUE "Comments", "MY-BASIC"
 				VALUE "CompanyName", "Wang Renxin"
 				VALUE "FileDescription", "MY-BASIC Interpreter for Windows"
-				VALUE "FileVersion", "1, 1, 68, 0"
+				VALUE "FileVersion", "1, 1, 69, 0"
 				VALUE "InternalName", "my_basic"
 				VALUE "LegalCopyright", "Copyright (C) 2011 - 2015 Wang Renxin"
 				VALUE "LegalTrademarks", "MY-BASIC"
 				VALUE "OriginalFilename", "my_basic.exe"
 				VALUE "ProductName", "MY-BASIC"
-				VALUE "ProductVersion", "1, 1, 68, 0"
+				VALUE "ProductVersion", "1, 1, 69, 0"
 			END
 		END
 		BLOCK "VarFileInfo"