X-Git-Url: http://deadsoftware.ru/gitweb?p=dsw-obn.git;a=blobdiff_plain;f=src%2Foberon.c;h=b428ecf73f6bda15c85365a8d49a5dd6aafb45ad;hp=cefd46928194b60c17099c25211692000f067ff4;hb=e9b64944925eadc5022edfee26281a4814fd9124;hpb=56540110475558bb4cb3d1dad559f9050b35e80f

diff --git a/src/oberon.c b/src/oberon.c
index cefd469..b428ecf 100644
--- a/src/oberon.c
+++ b/src/oberon.c
@@ -33,6 +33,8 @@ enum {
 	LEQ,
 	GREAT,
 	GEQ,
+	IN,
+	IS,
 	PLUS,
 	MINUS,
 	OR,
@@ -57,7 +59,13 @@ enum {
 	UPARROW,
 	NIL,
 	IMPORT,
-	REAL
+	REAL,
+	CHAR,
+	STRING,
+	IF,
+	THEN,
+	ELSE,
+	ELSIF
 };
 
 // =======================================================================
@@ -114,6 +122,24 @@ oberon_new_type_real(int size)
 	return x;
 }
 
+static oberon_type_t *
+oberon_new_type_char(int size)
+{
+	oberon_type_t * x;
+	x = oberon_new_type_ptr(OBERON_TYPE_CHAR);
+	x -> size = size;
+	return x;
+}
+
+static oberon_type_t *
+oberon_new_type_string(int size)
+{
+	oberon_type_t * x;
+	x = oberon_new_type_ptr(OBERON_TYPE_STRING);
+	x -> size = size;
+	return x;
+}
+
 // =======================================================================
 //   TABLE
 // ======================================================================= 
@@ -350,6 +376,30 @@ oberon_read_ident(oberon_context_t * ctx)
 	{
 		ctx -> token = IMPORT;
 	}
+	else if(strcmp(ident, "IN") == 0)
+	{
+		ctx -> token = IN;
+	}
+	else if(strcmp(ident, "IS") == 0)
+	{
+		ctx -> token = IS;
+	}
+	else if(strcmp(ident, "IF") == 0)
+	{
+		ctx -> token = IF;
+	}
+	else if(strcmp(ident, "THEN") == 0)
+	{
+		ctx -> token = THEN;
+	}
+	else if(strcmp(ident, "ELSE") == 0)
+	{
+		ctx -> token = ELSE;
+	}
+	else if(strcmp(ident, "ELSIF") == 0)
+	{
+		ctx -> token = ELSIF;
+	}
 }
 
 static void
@@ -367,6 +417,7 @@ oberon_read_number(oberon_context_t * ctx)
 	 * mode = 1 == HEX
 	 * mode = 2 == REAL
 	 * mode = 3 == LONGREAL
+	 * mode = 4 == CHAR
 	 */
 	int mode = 0;
 	start_i = ctx -> code_index;
@@ -388,11 +439,20 @@ oberon_read_number(oberon_context_t * ctx)
 
 		end_i = ctx -> code_index;
 
-		if(ctx -> c != 'H')
+		if(ctx -> c == 'H')
+		{
+			mode = 1;
+			oberon_get_char(ctx);
+		}
+		else if(ctx -> c == 'X')
+		{
+			mode = 4;
+			oberon_get_char(ctx);
+		}
+		else
 		{
 			oberon_error(ctx, "invalid hex number");
 		}
-		oberon_get_char(ctx);
 	}
 	else if(ctx -> c == '.')
 	{
@@ -430,6 +490,20 @@ oberon_read_number(oberon_context_t * ctx)
 		end_i = ctx -> code_index;
 	}
 
+	if(mode == 0)
+	{
+		if(ctx -> c == 'H')
+		{
+			mode = 1;
+			oberon_get_char(ctx);
+		}
+		else if(ctx -> c == 'X')
+		{
+			mode = 4;
+			oberon_get_char(ctx);
+		}
+	}
+
 	int len = end_i - start_i;
 	ident = malloc(len + 1);
 	memcpy(ident, &ctx -> code[start_i], len);
@@ -460,6 +534,11 @@ oberon_read_number(oberon_context_t * ctx)
 			sscanf(ident, "%lf", &real);
 			ctx -> token = REAL;
 			break;
+		case 4:
+			sscanf(ident, "%lx", &integer);
+			real = integer;
+			ctx -> token = CHAR;
+			break;
 		default:
 			oberon_error(ctx, "oberon_read_number: wat");
 			break;
@@ -514,6 +593,36 @@ oberon_read_comment(oberon_context_t * ctx)
 	}
 }
 
+static void oberon_read_string(oberon_context_t * ctx)
+{
+	int c = ctx -> c;
+	oberon_get_char(ctx);
+
+	int start = ctx -> code_index;
+
+	while(ctx -> c != 0 && ctx -> c != c)
+	{
+		oberon_get_char(ctx);
+	}
+
+	if(ctx -> c == 0)
+	{
+		oberon_error(ctx, "unterminated string");
+	}
+
+	int end = ctx -> code_index;
+
+	oberon_get_char(ctx);
+
+	char * string = calloc(1, end - start + 1);
+	strncpy(string, &ctx -> code[start], end - start);
+
+	ctx -> token = STRING;
+	ctx -> string = string;
+
+	printf("oberon_read_string: string ((%s))\n", string);
+}
+
 static void oberon_read_token(oberon_context_t * ctx);
 
 static void
@@ -627,6 +736,12 @@ oberon_read_symbol(oberon_context_t * ctx)
 			ctx -> token = UPARROW;
 			oberon_get_char(ctx);
 			break;
+		case '"':
+			oberon_read_string(ctx);
+			break;
+		case '\'':
+			oberon_read_string(ctx);
+			break;			
 		default:
 			oberon_error(ctx, "invalid char %c", ctx -> c);
 			break;
@@ -663,6 +778,7 @@ static void oberon_assert_token(oberon_context_t * ctx, int token);
 static char * oberon_assert_ident(oberon_context_t * ctx);
 static void oberon_type(oberon_context_t * ctx, oberon_type_t ** type);
 static oberon_item_t * oberon_const_expr(oberon_context_t * ctx);
+static oberon_expr_t * oberno_make_dereferencing(oberon_context_t * ctx, oberon_expr_t * expr);
 
 static oberon_expr_t *
 oberon_new_operator(int op, oberon_type_t * result, oberon_expr_t * left, oberon_expr_t * right)
@@ -736,7 +852,14 @@ oberon_expr_list(oberon_context_t * ctx, int * num_expr, oberon_expr_t ** first,
 	oberon_expr_t * last;
 
 	*num_expr = 1;
-	*first = last = oberon_expr(ctx);
+	if(const_expr)
+	{
+		*first = last = (oberon_expr_t *) oberon_const_expr(ctx);
+	}
+	else
+	{
+		*first = last = oberon_expr(ctx);
+	}
 	while(ctx -> token == COMMA)
 	{
 		oberon_assert_token(ctx, COMMA);
@@ -760,18 +883,25 @@ oberon_expr_list(oberon_context_t * ctx, int * num_expr, oberon_expr_t ** first,
 static oberon_expr_t *
 oberon_cast_expr(oberon_context_t * ctx, oberon_expr_t * expr, oberon_type_t * pref)
 {
-	oberon_expr_t * cast;
-	cast = oberon_new_item(MODE_CAST, pref, expr -> read_only);
-	cast -> item.parent = expr;
-	cast -> next = expr -> next;
-	return cast;
+	return oberon_new_operator(OP_CAST, pref, expr, NULL);
 }
 
 static oberon_expr_t *
 oberno_make_record_cast(oberon_context_t * ctx, oberon_expr_t * expr, oberon_type_t * rec)
 {
-	if(expr -> result -> class != OBERON_TYPE_RECORD
-		|| rec -> class != OBERON_TYPE_RECORD)
+	oberon_type_t * from = expr -> result;
+	oberon_type_t * to = rec;
+
+	printf("oberno_make_record_cast: from class %i to class %i\n", from -> class, to -> class);
+
+	if(from -> class == OBERON_TYPE_POINTER && to -> class == OBERON_TYPE_POINTER)
+	{
+		printf("oberno_make_record_cast: pointers\n");
+		from = from -> base;
+		to = to -> base;
+	}
+
+	if(from -> class != OBERON_TYPE_RECORD || to -> class != OBERON_TYPE_RECORD)
 	{
 		oberon_error(ctx, "must be record type");
 	}
@@ -807,39 +937,78 @@ oberon_get_equal_expr_type(oberon_context_t * ctx, oberon_type_t * a, oberon_typ
 	return result;
 }
 
+static void
+oberon_check_record_compatibility(oberon_context_t * ctx, oberon_type_t * from, oberon_type_t * to)
+{
+	if(from -> class == OBERON_TYPE_POINTER && to -> class == OBERON_TYPE_POINTER)
+	{
+		from = from -> base;
+		to = to -> base;
+	}
+
+	if(from -> class != OBERON_TYPE_RECORD || to -> class != OBERON_TYPE_RECORD)
+	{
+		oberon_error(ctx, "not a record");
+	}
+
+	oberon_type_t * t = from;
+	while(t != NULL && t != to)
+	{
+		t = t -> base;
+	}
+
+	if(t == NULL)
+	{
+		oberon_error(ctx, "incompatible record types");
+	}
+}
+
 static oberon_expr_t *
 oberon_autocast_to(oberon_context_t * ctx, oberon_expr_t * expr, oberon_type_t * pref)
 {
+	// Допускается:
+	//  Если классы типов равны
+	//  Если INTEGER переводится в REAL
+	//  Есди STRING переводится в ARRAY OF CHAR
+
+	bool error = false;
 	if(pref -> class != expr -> result -> class)
 	{
-		if(pref -> class == OBERON_TYPE_POINTER)
+		printf("expr class %i\n", expr -> result -> class);
+		printf("pref class %i\n", pref -> class);
+
+		if(expr -> result -> class == OBERON_TYPE_STRING)
 		{
-			if(expr -> result -> class == OBERON_TYPE_POINTER)
+			if(pref -> class == OBERON_TYPE_ARRAY)
 			{
-				// accept
+				if(pref -> base -> class != OBERON_TYPE_CHAR)
+				{
+					error = true;
+				}
 			}
 			else
 			{
-				oberon_error(ctx, "incompatible types");
+				error = true;
 			}
 		}
-		else if(pref -> class == OBERON_TYPE_REAL)
+		else if(expr -> result -> class == OBERON_TYPE_INTEGER)
 		{
-			if(expr -> result -> class == OBERON_TYPE_INTEGER)
+			if(pref -> class != OBERON_TYPE_REAL)
 			{
-				// accept
-			}
-			else
-			{
-				oberon_error(ctx, "incompatible types");
+				error = true;
 			}
 		}
 		else
 		{
-			oberon_error(ctx, "incompatible types");
+			error = true;
 		}
 	}
 
+	if(error)
+	{
+		oberon_error(ctx, "oberon_autocast_to: incompatible types");
+	}
+
 	if(pref -> class == OBERON_TYPE_INTEGER || pref -> class == OBERON_TYPE_REAL)
 	{
 		if(expr -> result -> size > pref -> size)
@@ -853,24 +1022,18 @@ oberon_autocast_to(oberon_context_t * ctx, oberon_expr_t * expr, oberon_type_t *
 	}
 	else if(pref -> class == OBERON_TYPE_RECORD)
 	{
-		oberon_type_t * t = expr -> result;
-		while(t != NULL && t != pref)
-		{
-			t = t -> base;
-		}
-		if(t == NULL)
-		{
-			printf("oberon_autocast_to: rec %p != %p\n", expr -> result, pref);
-			oberon_error(ctx, "incompatible record types");
-		}
-		if(expr -> result != pref)
-		{
-			expr = oberno_make_record_cast(ctx, expr, pref);
-		}
+		oberon_check_record_compatibility(ctx, expr -> result, pref);
+		expr = oberno_make_record_cast(ctx, expr, pref);
 	}
 	else if(pref -> class == OBERON_TYPE_POINTER)
 	{
-		if(expr -> result -> base != pref -> base)
+		assert(pref -> base);
+		if(expr -> result -> base -> class == OBERON_TYPE_RECORD)
+		{
+			oberon_check_record_compatibility(ctx, expr -> result, pref);
+			expr = oberno_make_record_cast(ctx, expr, pref);
+		}
+		else if(expr -> result -> base != pref -> base)
 		{
 			if(expr -> result -> base -> class != OBERON_TYPE_VOID)
 			{
@@ -893,25 +1056,15 @@ oberon_autocast_binary_op(oberon_context_t * ctx, oberon_expr_t ** ea, oberon_ex
 }
 
 static void
-oberon_autocast_call(oberon_context_t * ctx, oberon_expr_t * desig)
+oberon_autocast_call(oberon_context_t * ctx, oberon_item_t * desig)
 {
-	if(desig -> is_item == 0)
-	{
-		oberon_error(ctx, "expected item");
-	}
-
-	if(desig -> item.mode != MODE_CALL)
+	if(desig -> mode != MODE_CALL)
 	{
 		oberon_error(ctx, "expected mode CALL");
 	}
 
-	if(desig -> item.var -> type -> class != OBERON_TYPE_PROCEDURE)
-	{
-		oberon_error(ctx, "only procedures can be called");
-	}
-
-	oberon_type_t * fn = desig -> item.var -> type;
-	int num_args = desig -> item.num_args;
+	oberon_type_t * fn = desig -> parent -> result;
+	int num_args = desig -> num_args;
 	int num_decl = fn -> num_decl;
 
 	if(num_args < num_decl)
@@ -925,7 +1078,7 @@ oberon_autocast_call(oberon_context_t * ctx, oberon_expr_t * desig)
 
 	/* Делаем проверку на запись и делаем автокаст */
 	oberon_expr_t * casted[num_args];
-	oberon_expr_t * arg = desig -> item.args;
+	oberon_expr_t * arg = desig -> args;
 	oberon_object_t * param = fn -> decl;
 	for(int i = 0; i < num_args; i++)
 	{
@@ -950,62 +1103,84 @@ oberon_autocast_call(oberon_context_t * ctx, oberon_expr_t * desig)
 		{
 			casted[i] -> next = casted[i + 1];
 		}
-		desig -> item.args = arg;
+		desig -> args = arg;
 	}
 }
 
 static oberon_expr_t *
-oberon_make_call_func(oberon_context_t * ctx, oberon_object_t * proc, int num_args, oberon_expr_t * list_args)
+oberon_make_call_func(oberon_context_t * ctx, oberon_item_t * item, int num_args, oberon_expr_t * list_args)
 {
-	switch(proc -> class)
+	oberon_type_t * signature = item -> result;
+	if(signature -> class != OBERON_TYPE_PROCEDURE)
 	{
-		case OBERON_CLASS_PROC:
-			if(proc -> class != OBERON_CLASS_PROC)
-			{
-				oberon_error(ctx, "not a procedure");
-			}
-			break;
-		case OBERON_CLASS_VAR:
-		case OBERON_CLASS_VAR_PARAM:
-		case OBERON_CLASS_PARAM:
-			if(proc -> type -> class != OBERON_TYPE_PROCEDURE)
-			{
-				oberon_error(ctx, "not a procedure");
-			}
-			break;
-		default:
-			oberon_error(ctx, "not a procedure");
-			break;
+		oberon_error(ctx, "not a procedure");
 	}
 
 	oberon_expr_t * call;
 
-	if(proc -> sysproc)
+	if(signature -> sysproc)
 	{
-		if(proc -> genfunc == NULL)
+		if(signature -> genfunc == NULL)
 		{
 			oberon_error(ctx, "not a function-procedure");
 		}
 
-		call = proc -> genfunc(ctx, num_args, list_args);
+		call = signature -> genfunc(ctx, num_args, list_args);
 	}
 	else
 	{
-		if(proc -> type -> base -> class == OBERON_TYPE_VOID)
+		if(signature -> base -> class == OBERON_TYPE_VOID)
 		{
 			oberon_error(ctx, "attempt to call procedure in expression");
 		}
 
-		call = oberon_new_item(MODE_CALL, proc -> type -> base, 1);
-		call -> item.var = proc;
+		call = oberon_new_item(MODE_CALL, signature -> base, true);
+		call -> item.parent = item;
 		call -> item.num_args = num_args;
 		call -> item.args = list_args;
-		oberon_autocast_call(ctx, call);
+		oberon_autocast_call(ctx, (oberon_item_t *) call);
 	}
 
 	return call;
 }
 
+static void
+oberon_make_call_proc(oberon_context_t * ctx, oberon_item_t * item, int num_args, oberon_expr_t * list_args)
+{
+	oberon_type_t * signature = item -> result;
+	if(signature -> class != OBERON_TYPE_PROCEDURE)
+	{
+		oberon_error(ctx, "not a procedure");
+	}
+
+	oberon_expr_t * call;
+
+	if(signature -> sysproc)
+	{
+		if(signature -> genproc == NULL)
+		{
+			oberon_error(ctx, "not a procedure");
+		}
+
+		signature -> genproc(ctx, num_args, list_args);
+	}
+	else
+	{
+		if(signature -> base -> class != OBERON_TYPE_VOID)
+		{
+			oberon_error(ctx, "attempt to call function as non-typed procedure");
+		}
+
+		call = oberon_new_item(MODE_CALL, signature -> base, true);
+		call -> item.parent = item;
+		call -> item.num_args = num_args;
+		call -> item.args = list_args;
+		oberon_autocast_call(ctx, (oberon_item_t *) call);
+		oberon_generate_call_proc(ctx, call);
+	}
+}
+
+/*
 static void
 oberon_make_call_proc(oberon_context_t * ctx, oberon_object_t * proc, int num_args, oberon_expr_t * list_args)
 {
@@ -1055,20 +1230,26 @@ oberon_make_call_proc(oberon_context_t * ctx, oberon_object_t * proc, int num_ar
 		oberon_generate_call_proc(ctx, call);
 	}
 }
+*/
 
 #define ISEXPR(x) \
 	(((x) == PLUS) \
 	|| ((x) == MINUS) \
 	|| ((x) == IDENT) \
 	|| ((x) == INTEGER) \
+	|| ((x) == REAL) \
+	|| ((x) == CHAR) \
+	|| ((x) == STRING) \
+	|| ((x) == NIL) \
 	|| ((x) == LPAREN) \
 	|| ((x) == NOT) \
 	|| ((x) == TRUE) \
-	|| ((x) == FALSE))
+	|| ((x) == FALSE)) 
 
 static oberon_expr_t *
 oberno_make_dereferencing(oberon_context_t * ctx, oberon_expr_t * expr)
 {
+	printf("oberno_make_dereferencing\n");
 	if(expr -> result -> class != OBERON_TYPE_POINTER)
 	{
 		oberon_error(ctx, "not a pointer");
@@ -1078,7 +1259,7 @@ oberno_make_dereferencing(oberon_context_t * ctx, oberon_expr_t * expr)
 
 	oberon_expr_t * selector;
 	selector = oberon_new_item(MODE_DEREF, expr -> result -> base, expr -> read_only);
-	selector -> item.parent = expr;
+	selector -> item.parent = (oberon_item_t *) expr;
 
 	return selector;
 }
@@ -1125,7 +1306,7 @@ oberon_make_array_selector(oberon_context_t * ctx, oberon_expr_t * desig, oberon
 
 	oberon_expr_t * selector;
 	selector = oberon_new_item(MODE_INDEX, base, desig -> read_only);
-	selector -> item.parent = desig;
+	selector -> item.parent = (oberon_item_t *) desig;
 	selector -> item.num_args = 1;
 	selector -> item.args = index;
 
@@ -1140,7 +1321,7 @@ oberon_make_record_selector(oberon_context_t * ctx, oberon_expr_t * expr, char *
 		expr = oberno_make_dereferencing(ctx, expr);
 	}
 
-	assert(expr -> is_item == 1);
+	assert(expr -> is_item);
 
 	if(expr -> result -> class != OBERON_TYPE_RECORD)
 	{
@@ -1172,7 +1353,7 @@ oberon_make_record_selector(oberon_context_t * ctx, oberon_expr_t * expr, char *
 	oberon_expr_t * selector;
 	selector = oberon_new_item(MODE_FIELD, field -> type, read_only);
 	selector -> item.var = field;
-	selector -> item.parent = expr;
+	selector -> item.parent = (oberon_item_t *) expr;
 
 	return selector;
 }
@@ -1254,7 +1435,7 @@ oberon_designator(oberon_context_t * ctx)
 	}
 	expr -> item.var = var;
 
-	while(ISSELECTOR(ctx -> token))
+	while(expr -> result -> class != OBERON_TYPE_PROCEDURE && ISSELECTOR(ctx -> token))
 	{
 		switch(ctx -> token)
 		{
@@ -1295,14 +1476,13 @@ oberon_designator(oberon_context_t * ctx)
 				break;
 		}
 	}
+
 	return expr;
 }
 
 static oberon_expr_t *
 oberon_opt_func_parens(oberon_context_t * ctx, oberon_expr_t * expr)
 {
-	assert(expr -> is_item == 1);
-
 	/* Если есть скобки - значит вызов. Если нет, то передаём указатель. */
 	if(ctx -> token == LPAREN)
 	{
@@ -1316,7 +1496,8 @@ oberon_opt_func_parens(oberon_context_t * ctx, oberon_expr_t * expr)
 			oberon_expr_list(ctx, &num_args, &arguments, 0);
 		}
 
-		expr = oberon_make_call_func(ctx, expr -> item.var, num_args, arguments);
+		assert(expr -> is_item == 1);
+		expr = oberon_make_call_func(ctx, (oberon_item_t *) expr, num_args, arguments);
 
 		oberon_assert_token(ctx, RPAREN);
 	}
@@ -1327,7 +1508,7 @@ oberon_opt_func_parens(oberon_context_t * ctx, oberon_expr_t * expr)
 static void
 oberon_opt_proc_parens(oberon_context_t * ctx, oberon_expr_t * expr)
 {
-	assert(expr -> is_item == 1);
+	assert(expr -> is_item);
 
 	int num_args = 0;
 	oberon_expr_t * arguments = NULL;
@@ -1345,7 +1526,7 @@ oberon_opt_proc_parens(oberon_context_t * ctx, oberon_expr_t * expr)
 	}
 
 	/* Вызов происходит даже без скобок */
-	oberon_make_call_proc(ctx, expr -> item.var, num_args, arguments);
+	oberon_make_call_proc(ctx, (oberon_item_t *) expr, num_args, arguments);
 }
 
 static oberon_type_t *
@@ -1383,10 +1564,22 @@ oberon_factor(oberon_context_t * ctx)
 			break;
 		case INTEGER:
 			result = oberon_get_type_of_int_value(ctx, ctx -> integer);
-			expr = oberon_new_item(MODE_INTEGER, result, 1);
+			expr = oberon_new_item(MODE_INTEGER, result, true);
 			expr -> item.integer = ctx -> integer;
 			oberon_assert_token(ctx, INTEGER);
 			break;
+		case CHAR:
+			result = ctx -> char_type;
+			expr = oberon_new_item(MODE_CHAR, result, true);
+			expr -> item.integer = ctx -> integer;
+			oberon_assert_token(ctx, CHAR);
+			break;
+		case STRING:
+			result = ctx -> string_type;
+			expr = oberon_new_item(MODE_STRING, result, true);
+			expr -> item.string = ctx -> string;
+			oberon_assert_token(ctx, STRING);
+			break;
 		case REAL:
 			result = (ctx -> longmode) ? (ctx -> longreal_type) : (ctx -> real_type);
 			expr = oberon_new_item(MODE_REAL, result, 1);
@@ -1394,12 +1587,12 @@ oberon_factor(oberon_context_t * ctx)
 			oberon_assert_token(ctx, REAL);
 			break;
 		case TRUE:
-			expr = oberon_new_item(MODE_BOOLEAN, ctx -> bool_type, 1);
+			expr = oberon_new_item(MODE_BOOLEAN, ctx -> bool_type, true);
 			expr -> item.boolean = true;
 			oberon_assert_token(ctx, TRUE);
 			break;
 		case FALSE:
-			expr = oberon_new_item(MODE_BOOLEAN, ctx -> bool_type, 1);
+			expr = oberon_new_item(MODE_BOOLEAN, ctx -> bool_type, true);
 			expr -> item.boolean = false;
 			oberon_assert_token(ctx, FALSE);
 			break;
@@ -1415,7 +1608,7 @@ oberon_factor(oberon_context_t * ctx)
 			break;
 		case NIL:
 			oberon_assert_token(ctx, NIL);
-			expr = oberon_new_item(MODE_NIL, ctx -> void_ptr_type, 1);
+			expr = oberon_new_item(MODE_NIL, ctx -> void_ptr_type, true);
 			break;
 		default:
 			oberon_error(ctx, "invalid expression");
@@ -1468,6 +1661,10 @@ oberon_make_bin_op(oberon_context_t * ctx, int token, oberon_expr_t * a, oberon_
 				|| b -> result -> class == OBERON_TYPE_INTEGER
 				|| a -> result -> class == OBERON_TYPE_REAL
 				|| b -> result -> class == OBERON_TYPE_REAL)
+			{
+				// accept
+			}
+			else
 			{
 				oberon_error(ctx, "used only with numeric types");
 			}
@@ -1629,7 +1826,7 @@ oberon_simple_expr(oberon_context_t * ctx)
 }
 
 #define ISRELATION(x) \
-	((x) >= EQUAL && (x) <= GEQ)
+	((x) >= EQUAL && (x) <= IS)
 
 static oberon_expr_t *
 oberon_expr(oberon_context_t * ctx)
@@ -2151,13 +2348,19 @@ oberon_type_record_body(oberon_context_t * ctx, oberon_type_t * rec)
 			oberon_error(ctx, "base must be type");
 		}
 
-		if(typeobj -> type -> class != OBERON_TYPE_RECORD)
+		oberon_type_t * base = typeobj -> type;
+		if(base -> class == OBERON_TYPE_POINTER)
+		{
+			base = base -> base;
+		}
+
+		if(base -> class != OBERON_TYPE_RECORD)
 		{
 			oberon_error(ctx, "base must be record type");
 		}
 
-		rec -> base = typeobj -> type;
-		ctx -> decl = rec -> base -> scope;
+		rec -> base = base;
+		ctx -> decl = base -> scope;
 
 		oberon_assert_token(ctx, RPAREN);
 	}
@@ -2666,6 +2869,9 @@ oberon_decl_seq(oberon_context_t * ctx)
 	oberon_prevent_undeclarated_procedures(ctx);
 }
 
+static void
+oberon_statement_seq(oberon_context_t * ctx);
+
 static void
 oberon_assign(oberon_context_t * ctx, oberon_expr_t * src, oberon_expr_t * dst)
 {
@@ -2698,6 +2904,53 @@ oberon_statement(oberon_context_t * ctx)
 			oberon_opt_proc_parens(ctx, item1);
 		}
 	}
+	else if(ctx -> token == IF)
+	{
+		gen_label_t * end;
+		gen_label_t * els;
+		oberon_expr_t * cond;
+
+		els = oberon_generator_reserve_label(ctx);
+		end = oberon_generator_reserve_label(ctx);
+
+		oberon_assert_token(ctx, IF);
+		cond = oberon_expr(ctx);
+		if(cond -> result -> class != OBERON_TYPE_BOOLEAN)
+		{
+			oberon_error(ctx, "condition must be boolean");
+		}
+		oberon_assert_token(ctx, THEN);
+		oberon_generate_branch(ctx, cond, false, els);
+		oberon_statement_seq(ctx);
+		oberon_generate_goto(ctx, end);
+		oberon_generate_label(ctx, els);
+
+		while(ctx -> token == ELSIF)
+		{
+			els = oberon_generator_reserve_label(ctx);
+
+			oberon_assert_token(ctx, ELSIF);
+			cond = oberon_expr(ctx);
+			if(cond -> result -> class != OBERON_TYPE_BOOLEAN)
+			{
+				oberon_error(ctx, "condition must be boolean");
+			}
+			oberon_assert_token(ctx, THEN);
+			oberon_generate_branch(ctx, cond, false, els);
+			oberon_statement_seq(ctx);
+			oberon_generate_goto(ctx, end);
+			oberon_generate_label(ctx, els);
+		}
+
+		if(ctx -> token == ELSE)
+		{
+			oberon_assert_token(ctx, ELSE);
+			oberon_statement_seq(ctx);
+		}
+
+		oberon_generate_label(ctx, end);
+		oberon_assert_token(ctx, END);		
+	}
 	else if(ctx -> token == RETURN)
 	{
 		oberon_assert_token(ctx, RETURN);
@@ -2843,6 +3096,9 @@ register_default_types(oberon_context_t * ctx)
 	ctx -> void_ptr_type -> base = ctx -> void_type;
 	oberon_generator_init_type(ctx, ctx -> void_ptr_type);
 
+	ctx -> string_type = oberon_new_type_string(1);
+	oberon_generator_init_type(ctx, ctx -> string_type);
+
 	ctx -> bool_type = oberon_new_type_boolean();
 	oberon_define_type(ctx -> world_scope, "BOOLEAN", ctx -> bool_type, 1);
 
@@ -2863,6 +3119,9 @@ register_default_types(oberon_context_t * ctx)
 
 	ctx -> longreal_type = oberon_new_type_real(8);
 	oberon_define_type(ctx -> world_scope, "LONGREAL", ctx -> longreal_type, 1);
+
+	ctx -> char_type = oberon_new_type_char(1);
+	oberon_define_type(ctx -> world_scope, "CHAR", ctx -> char_type, 1);
 }
 
 static void
@@ -2870,10 +3129,10 @@ oberon_new_intrinsic(oberon_context_t * ctx, char * name, GenerateFuncCallback f
 {
 	oberon_object_t * proc;
 	proc = oberon_define_object(ctx -> decl, name, OBERON_CLASS_PROC, true, false, false);
-	proc -> sysproc = 1;
-	proc -> genfunc = f;
-	proc -> genproc = p;
 	proc -> type = oberon_new_type_ptr(OBERON_TYPE_PROCEDURE);
+	proc -> type -> sysproc = true;
+	proc -> type -> genfunc = f;
+	proc -> type -> genproc = p;
 }
 
 static oberon_expr_t *