Implement enumeration

boot/stage14.elna

@@ -10,6 +10,7 @@
 (* - Space independent parsing. *)
 (* - Label names in goto statements aren't required to begin with a dot. *)
 (* - Dereferencing pointers pointing to word long data. *)
+(* - Enumeration type. *)
 
 const
 	symbol_builtin_name_int := "Int";
@@ -416,9 +417,21 @@ begin
 end;
 
 proc _compile_variable_expression();
+var
+	name: Word;
+	lookup_result: Word;
+	name_token: Word;
 begin
-	_compile_designator();
-	_write_z("\tlw t0, (t0)\n\0")
+	name := _lexer_global_get_start();
+	name_token := _lexer_global_get_end() + -name;
+	lookup_result := _symbol_table_lookup(@symbol_table_global, name, name_token);
+
+	if lookup_result <> 0 then
+		_compile_enumeration_value(lookup_result)
+	else
+		_compile_designator();
+		_write_z("\tlw t0, (t0)\n\0")
+	end
 end;
 
 (**
@@ -738,6 +751,50 @@ begin
 	_write_c('\n')
 end;
 
+proc _compile_enumeration_value(symbol: Word);
+var
+	enumeration_type: Word;
+	members: Word;
+	members_length: Word;
+	token_type: Word;
+	value_name: Word;
+	name_length: Word;
+	member_name: Word;
+	member_length: Word;
+	counter: Word;
+begin
+	enumeration_type := _type_info_get_type(symbol);
+	members := _enumeration_type_get_members(enumeration_type);
+	members_length := _enumeration_type_get_length(enumeration_type);
+
+	(* Skip enumeration type name and dot. Read the enumeration value. *)
+	_lexer_skip_token();
+	_lexer_read_token(@token_type);
+	_lexer_skip_token();
+	_lexer_read_token(@token_type);
+
+	value_name := _lexer_global_get_start();
+	name_length := _lexer_global_get_end() + -value_name;
+	_lexer_skip_token();
+	counter := 1;
+
+	.compile_enumeration_value_members;
+	if members_length > 0 then
+		member_name := _load_word(members);
+		member_length := _load_word(members + 4);
+
+		if _lexer_compare_keyword(value_name, name_length, member_name, member_length) = 0 then
+			members_length := members_length + -1;
+			members := members + 8;
+			counter := counter + 1;
+			goto .compile_enumeration_value_members
+		end;
+		_write_z("\tli t0, \0");
+		_write_i(counter);
+		_write_c('\n')
+	end
+end;
+
 proc _compile_designator();
 var
 	name_token: Word;
@@ -1040,7 +1097,7 @@ begin
 	_enumeration_type_set_members(result, memory_start);
 	_enumeration_type_set_length(result, member_count);
 
-	return result
+	return _type_info_create(result)
 end;
 
 proc _read_type_expression();
@@ -1104,6 +1161,24 @@ begin
 	return _load_word(this)
 end;
 
+proc _type_info_create(type_representation: Word);
+var
+	result: Word;
+	current_word: Word;
+begin
+	result := memory_free_pointer;
+	current_word := result;
+	(* 1 is INFO_TYPE *)
+	_store_word(1, current_word);
+
+	current_word := current_word + 4;
+	_store_word(type_representation, current_word);
+
+	memory_free_pointer := current_word + 4;
+
+	return result
+end;
+
 (**
  * Parameters:
  * temporary_index - Parameter index.
@@ -1427,11 +1502,20 @@ end;
 proc _compile_type_declaration();
 var
 	token_kind: Word;
+	type_name: Word;
+	name_length: Word;
+	type_info: Word;
 begin
+	type_name := _lexer_global_get_start();
+	name_length := _lexer_global_get_end() + -type_name;
+
 	_lexer_skip_token();
 	_lexer_read_token(@token_kind);
 	_lexer_skip_token();
-	_read_type_expression();
+	type_info := _read_type_expression();
+
+	_symbol_table_enter(@symbol_table_global, type_name, name_length, type_info);
+
 	_lexer_read_token(@token_kind);
 	_lexer_skip_token()
 end;