1 files changed, 207 insertions, 143 deletions

diff --git a/boot/stage17/cl.elna b/boot/stage17/cl.elna
index 7a33f6e..e10be76 100644
--- a/boot/stage17/cl.elna
+++ b/boot/stage17/cl.elna
@@ -7,6 +7,8 @@ program;
 
 (* Stage 17 compiler. *)
 
+(* - true and false boolean literals. *)
+
 type
 	(**
 	 * List of intermediate representation items.
@@ -14,6 +16,10 @@ type
 	ElnaInstructionList = record
 		next: Word
 	end;
+	ElnaInstructionModule = record
+		data: Word;
+		code: Word
+	end;
 	ElnaInstructionDeclaration = record
 		next: Word;
 		name: Word;
@@ -44,6 +50,11 @@ type
 		kind: Word;
 		type_decoration: Word
 	end;
+	ElnaTreeBooleanLiteral = record
+		kind: Word;
+		type_decoration: Word;
+		value: Word
+	end;
 	ElnaTreeVariableExpression = record
 		kind: Word;
 		type_decoration: Word;
@@ -74,28 +85,39 @@ type
 		operand: Word;
 		operator: Word
 	end;
-	_if_statement = record
-		kind: Word;
-		next: Word;
-		conditionals: Word;
-		_else: Word
-	end;
 
 	(**
 	 * All statements are chained into a list. Next contains a pointer to the next
 	 * statement in the statement list.
 	 *)
-	_statement = record
+	ElnaTreeStatement = record
 		kind: Word;
 		next: Word
 	end;
-	_goto_statement = record
+	ElnaTreeIfStatement = record
+		kind: Word;
+		next: Word;
+		conditionals: Word;
+		_else: Word
+	end;
+	ElnaTreeGotoStatement = record
 		kind: Word;
 		next: Word;
 		label: Word;
 		length: Word
 	end;
-	_label_declaration = record
+	ElnaTreeAssignStatement = record
+		kind: Word;
+		next: Word;
+		assignee: Word;
+		assignment: Word
+	end;
+	ElnaTreeReturnStatement = record
+		kind: Word;
+		next: Word;
+		returned: Word
+	end;
+	ElnaTreeLabelDeclaration = record
 		kind: Word;
 		next: Word;
 		label: Word;
@@ -113,27 +135,6 @@ type
 		members: Word;
 		length: Word
 	end;
-	ElnaInstructionModule = record
-		data: Word;
-		code: Word
-	end;
-	_module_declaration = record
-		kind: Word;
-		types: Word;
-		globals: Word;
-		procedures: Word
-	end;
-	_assign_statement = record
-		kind: Word;
-		next: Word;
-		assignee: Word;
-		assignment: Word
-	end;
-	_return_statement = record
-		kind: Word;
-		next: Word;
-		returned: Word
-	end;
 	ElnaTreeRecordTypeExpression = record
 		kind: Word;
 		members: Word;
@@ -153,6 +154,51 @@ type
 		base: Word;
 		length: Word
 	end;
+	(**
+	 * Conditional statements is a list of pairs: condition and statements.
+	 * Used for example to represent if and elsif blocks with beloning statements.
+	 *)
+	ElnaTreeConditionalStatements = record
+		condition: Word;
+		statements: Word;
+		next: Word
+	end;
+	ElnaTreeDeclaration = record
+		kind: Word;
+		next: Word;
+		name: Word;
+		length: Word
+	end;
+	ElnaTreeModuleDeclaration = record
+		kind: Word;
+		types: Word;
+		globals: Word;
+		procedures: Word
+	end;
+	ElnaTreeProcedureDeclaration = record
+		kind: Word;
+		next: Word;
+		name: Word;
+		length: Word;
+		body: Word;
+		temporaries: Word;
+		parameters: Word
+	end;
+	ElnaTreeTypeDeclaration = record
+		kind: Word;
+		next: Word;
+		name: Word;
+		length: Word;
+		_type: Word
+	end;
+	ElnaTreeVariableDeclaration = record
+		kind: Word;
+		next: Word;
+		name: Word;
+		length: Word;
+		_type: Word
+	end;
+
 	ElnaType = record
 		kind: Word;
 		size: Word
@@ -207,46 +253,6 @@ type
 		symbol_table: Word
 	end;
 
-	(**
-	 * Conditional statements is a list of pairs: condition and statements.
-	 * Used for example to represent if and elsif blocks with beloning statements.
-	 *)
-	_conditional_statements = record
-		condition: Word;
-		statements: Word;
-		next: Word
-	end;
-
-	_declaration = record
-		kind: Word;
-		next: Word;
-		name: Word;
-		length: Word
-	end;
-	_procedure_declaration = record
-		kind: Word;
-		next: Word;
-		name: Word;
-		length: Word;
-		body: Word;
-		temporaries: Word;
-		parameters: Word
-	end;
-	_type_declaration = record
-		kind: Word;
-		next: Word;
-		name: Word;
-		length: Word;
-		_type: Word
-	end;
-	_variable_declaration = record
-		kind: Word;
-		next: Word;
-		name: Word;
-		length: Word;
-		_type: Word
-	end;
-
 	ElnaLexerAction = (none, accumulate, skip, single, eof, finalize, composite, key_id, integer, delimited);
 
 	(**
@@ -317,8 +323,7 @@ type
 		_do,
 		_extern,
 		_record,
-		_true,
-		_false,
+		boolean,
 		null,
 		and,
 		_or,
@@ -371,6 +376,7 @@ type
 		integer_literal,
 		string_literal,
 		character_literal,
+		boolean_literal,
 		variable_expression,
 		field_access_expression,
 		dereference_expression,
@@ -1579,6 +1585,23 @@ begin
 	return result
 end;
 
+proc elna_parser_boolean_literal();
+var
+	boolean_token: Word;
+	result: ^ElnaTreeBooleanLiteral;
+begin
+	result := malloc(ElnaTreeBooleanLiteral_size());
+
+	boolean_token := _elna_lexer_global_get_start();
+	_elna_lexer_skip_token();
+
+	result^.kind := ElnaTreeKind.boolean_literal;
+	result^.value := string_compare(boolean_token, 4, "true", 4);
+	result^.type_decoration := nil;
+
+	return result
+end;
+
 proc elna_parser_nil_literal();
 var
 	result: ^ElnaTreeNilLiteral;
@@ -1601,6 +1624,15 @@ begin
 	return nil
 end;
 
+proc _elna_tac_boolean_literal(boolean_literal_node: ^ElnaTreeBooleanLiteral, operand_type: Word, operand_value: Word, operand_length: Word);
+begin
+	operand_type^ := ElnaTacOperand.immediate;
+	operand_value^ := boolean_literal_node^.value;
+	operand_length^ := 0;
+
+	return nil
+end;
+
 proc _elna_tac_nil_literal(nil_node: Word, operand_type: Word, operand_value: Word, operand_length: Word);
 begin
 	operand_type^ := ElnaTacOperand.immediate;
@@ -1737,6 +1769,8 @@ begin
 		parser_node := elna_parser_integer_literal()
 	elsif token_kind = ElnaLexerKind.string then
 		parser_node := elna_parser_string_literal()
+	elsif token_kind = ElnaLexerKind.boolean then
+		parser_node := elna_parser_boolean_literal()
 	elsif token_kind = ElnaLexerKind.null then
 		parser_node := elna_parser_nil_literal()
 	elsif token_kind = ElnaLexerKind.identifier then
@@ -1792,6 +1826,8 @@ begin
 		instruction := _elna_tac_string_literal(parser_node, operand_type, operand_value, operand_length)
 	elsif parser_node^.kind = ElnaTreeKind.integer_literal then
 		instruction := _elna_tac_integer_literal(parser_node, operand_type, operand_value, operand_length)
+	elsif parser_node^.kind = ElnaTreeKind.boolean_literal then
+		instruction := _elna_tac_boolean_literal(parser_node, operand_type, operand_value, operand_length)
 	elsif parser_node^.kind = ElnaTreeKind.null then
 		instruction := _elna_tac_nil_literal(parser_node, operand_type, operand_value, operand_length)
 	else
@@ -2105,7 +2141,7 @@ end;
 proc elna_parser_call(callee: Word);
 var
 	parsed_expression: Word;
-	result: ^_statement;
+	result: ^ElnaTreeStatement;
 	argument_number: Word;
 	token_kind: Word;
 begin
@@ -2230,7 +2266,7 @@ var
 	token_kind: Word;
 	label_name: Word;
 	label_length: Word;
-	result: ^_goto_statement;
+	result: ^ElnaTreeGotoStatement;
 begin
 	_elna_lexer_skip_token();
 	_elna_lexer_read_token(@token_kind);
@@ -2239,7 +2275,7 @@ begin
 	label_length := _elna_lexer_global_get_end() - label_name;
 	_elna_lexer_skip_token();
 
-	result := malloc(_goto_statement_size());
+	result := malloc(ElnaTreeGotoStatement_size());
 
 	result^.kind := ElnaTreeKind.goto_statement;
 	result^.next := nil;
@@ -2249,7 +2285,7 @@ begin
 	return result
 end;
 
-proc _elna_tac_goto_statement(parser_node: ^_goto_statement);
+proc _elna_tac_goto_statement(parser_node: ^ElnaTreeGotoStatement);
 var
 	label_length: Word;
 	label_with_dot: Word;
@@ -2271,7 +2307,7 @@ var
 	token_kind: Word;
 	label_name: Word;
 	label_length: Word;
-	result: ^_goto_statement;
+	result: ^ElnaTreeGotoStatement;
 begin
 	_elna_lexer_skip_token();
 	_elna_lexer_read_token(@token_kind);
@@ -2280,7 +2316,7 @@ begin
 	label_length := _elna_lexer_global_get_end() - label_name;
 	_elna_lexer_skip_token();
 
-	result := malloc(_label_declaration_size());
+	result := malloc(ElnaTreeLabelDeclaration_size());
 
 	result^.kind := ElnaTreeKind.label_declaration;
 	result^.next := nil;
@@ -2290,7 +2326,7 @@ begin
 	return result
 end;
 
-proc _elna_tac_label_declaration(parser_node: ^_label_declaration);
+proc _elna_tac_label_declaration(parser_node: ^ElnaTreeLabelDeclaration);
 	return _elna_tac_label(parser_node^.label, parser_node^.length)
 end;
 
@@ -2447,10 +2483,10 @@ end;
 
 proc elna_parser_assign_statement(assignee: Word);
 var
-	result: ^_assign_statement;
+	result: ^ElnaTreeAssignStatement;
 	token_kind: Word;
 begin
-	result := malloc(_assign_statement_size());
+	result := malloc(ElnaTreeAssignStatement_size());
 
 	result^.kind := ElnaTreeKind.assign_statement;
 	result^.next := nil;
@@ -2465,7 +2501,7 @@ begin
 	return result
 end;
 
-proc _elna_tac_assign_statement(parser_tree: ^_assign_statement, symbol_table: Word);
+proc _elna_tac_assign_statement(parser_tree: ^ElnaTreeAssignStatement, symbol_table: Word);
 var
 	is_address: Word;
 	first_instruction: Word;
@@ -2523,14 +2559,14 @@ var
 	token_kind: Word;
 	returned: Word;
 	label_length: Word;
-	result: ^_return_statement;
+	result: ^ElnaTreeReturnStatement;
 begin
 	(* Skip "return" keyword and whitespace after it. *)
 	_elna_lexer_skip_token();
 	_elna_lexer_read_token(@token_kind);
 
 	returned := elna_parser_binary_expression();
-	result := malloc(_return_statement_size());
+	result := malloc(ElnaTreeReturnStatement_size());
 
 	result^.kind := ElnaTreeKind.return_statement;
 	result^.next := nil;
@@ -2539,7 +2575,7 @@ begin
 	return result
 end;
 
-proc _elna_tac_return_statement(parser_node: ^_return_statement, symbol_table: Word);
+proc _elna_tac_return_statement(parser_node: ^ElnaTreeReturnStatement, symbol_table: Word);
 var
 	first_instruction: Word;
 	instruction: Word;
@@ -2583,9 +2619,9 @@ end;
 proc elna_parser_conditional_statements();
 var
 	token_kind: Word;
-	result: ^_conditional_statements;
+	result: ^ElnaTreeConditionalStatements;
 begin
-	result := malloc(_conditional_statements_size());
+	result := malloc(ElnaTreeConditionalStatements_size());
 
 	(* Skip "if", "while" or "elsif". *)
 	_elna_lexer_skip_token();
@@ -2601,7 +2637,7 @@ begin
 	return result
 end;
 
-proc _elna_tac_conditional_statements(parser_node: ^_conditional_statements, after_end_label: Word, symbol_table: Word);
+proc _elna_tac_conditional_statements(parser_node: ^ElnaTreeConditionalStatements, after_end_label: Word, symbol_table: Word);
 var
 	condition_label: Word;
 	instruction: Word;
@@ -2645,12 +2681,12 @@ end;
 
 proc elna_parser_if_statement();
 var
-	result: ^_if_statement;
+	result: ^ElnaTreeIfStatement;
 	token_kind: Word;
-	previous_conditional: ^_conditional_statements;
-	next_conditional: ^_conditional_statements;
+	previous_conditional: ^ElnaTreeConditionalStatements;
+	next_conditional: ^ElnaTreeConditionalStatements;
 begin
-	result := malloc(_if_statement_size());
+	result := malloc(ElnaTreeIfStatement_size());
 
 	result^.kind := ElnaTreeKind.if_statement;
 	result^.next := nil;
@@ -2707,9 +2743,9 @@ end;
 proc elna_parser_statements();
 var
 	token_kind: Word;
-	previous_statement: ^_statement;
-	next_statement: ^_statement;
-	first_statement: ^_statement;
+	previous_statement: ^ElnaTreeStatement;
+	next_statement: ^ElnaTreeStatement;
+	first_statement: ^ElnaTreeStatement;
 begin
 	_skip_empty_lines();
 
@@ -2741,7 +2777,7 @@ end;
 
 proc _elna_tac_statements(parser_node: Word, symbol_table: Word);
 var
-	current_statement: ^_statement;
+	current_statement: ^ElnaTreeStatement;
 	instruction: Word;
 	first_instruction: Word;
 	current_instruction: Word;
@@ -2767,9 +2803,9 @@ begin
 	return first_instruction
 end;
 
-proc _elna_tac_if_statement(parser_node: ^_if_statement, symbol_table: Word);
+proc _elna_tac_if_statement(parser_node: ^ElnaTreeIfStatement, symbol_table: Word);
 var
-	current_node: ^_conditional_statements;
+	current_node: ^ElnaTreeConditionalStatements;
 	after_end_label: Word;
 	condition_label: Word;
 	first_instruction: Word;
@@ -3269,7 +3305,7 @@ end;
  * Parameters:
  * parameter_index - Parameter index.
  *)
-proc elna_name_procedure_parameter(parser_node: ^_variable_declaration, parameter_index: Word, symbol_table: Word);
+proc elna_name_procedure_parameter(parser_node: ^ElnaTreeVariableDeclaration, parameter_index: Word, symbol_table: Word);
 var
 	info: Word;
 	variable_type: Word;
@@ -3284,7 +3320,7 @@ end;
  * Parameters:
  * variable_index - Variable index.
  *)
-proc elna_name_procedure_temporary(parser_node: ^_variable_declaration, variable_index: Word, symbol_table: Word);
+proc elna_name_procedure_temporary(parser_node: ^ElnaTreeVariableDeclaration, variable_index: Word, symbol_table: Word);
 var
 	info: Word;
 	variable_type: Word;
@@ -3295,7 +3331,7 @@ begin
 	_symbol_table_enter(symbol_table, parser_node^.name, parser_node^.length, info)
 end;
 
-proc elna_name_procedure_temporaries(parser_node: ^_variable_declaration, symbol_table: Word);
+proc elna_name_procedure_temporaries(parser_node: ^ElnaTreeVariableDeclaration, symbol_table: Word);
 var
 	temporary_counter: Word;
 begin
@@ -3313,13 +3349,13 @@ end;
 
 proc elna_parser_procedure_declaration();
 var
-	next_declaration: ^_declaration;
-	current_declaration: ^_declaration;
+	next_declaration: ^ElnaTreeDeclaration;
+	current_declaration: ^ElnaTreeDeclaration;
 	token_kind: Word;
-	result: ^_procedure_declaration;
-	parameter_head: ^_declaration;
+	result: ^ElnaTreeProcedureDeclaration;
+	parameter_head: ^ElnaTreeDeclaration;
 begin
-	result := malloc(_procedure_declaration_size());
+	result := malloc(ElnaTreeProcedureDeclaration_size());
 
 	result^.kind := ElnaTreeKind.procedure_declaration;
 	result^.next := nil;
@@ -3386,7 +3422,7 @@ begin
 	return result
 end;
 
-proc _elna_tac_parameters(current_parameter: ^_declaration, new_symbol_table: Word);
+proc _elna_tac_parameters(current_parameter: ^ElnaTreeDeclaration, new_symbol_table: Word);
 var
 	name_pointer: Word;
 	name_length: Word;
@@ -3460,7 +3496,7 @@ begin
 	return result
 end;
 
-proc _elna_tac_procedure_declaration(parser_node: _procedure_declaration);
+proc _elna_tac_procedure_declaration(parser_node: ElnaTreeProcedureDeclaration);
 var
 	current_parameter: Word;
 	new_symbol_table: Word;
@@ -3494,9 +3530,9 @@ end;
 
 proc elna_parser_procedures();
 var
-	parser_node: ^_declaration;
-	result: ^_declaration;
-	current_declaration: ^_declaration;
+	parser_node: ^ElnaTreeDeclaration;
+	result: ^ElnaTreeDeclaration;
+	current_declaration: ^ElnaTreeDeclaration;
 	token_kind: Word;
 begin
 	result := nil;
@@ -3579,7 +3615,7 @@ begin
 	return first_copy
 end;
 
-proc _elna_tac_procedures(parser_node: ^_declaration);
+proc _elna_tac_procedures(parser_node: ^ElnaTreeDeclaration);
 var
 	result: Word;
 	current_procedure: ^ElnaInstructionList;
@@ -3628,7 +3664,7 @@ var
 	token_kind: Word;
 	type_name: Word;
 	name_length: Word;
-	result: ^_type_declaration;
+	result: ^ElnaTreeTypeDeclaration;
 begin
 	_elna_lexer_read_token(@token_kind);
 	type_name := _elna_lexer_global_get_start();
@@ -3638,7 +3674,7 @@ begin
 	_elna_lexer_read_token(@token_kind);
 	_elna_lexer_skip_token();
 
-	result := malloc(_type_declaration_size());
+	result := malloc(ElnaTreeTypeDeclaration_size());
 
 	result^.kind := ElnaTreeKind.type_declaration;
 	result^.next := nil;
@@ -3652,7 +3688,7 @@ begin
 	return result
 end;
 
-proc elna_name_type_declaration(parser_node: ^_type_declaration);
+proc elna_name_type_declaration(parser_node: ^ElnaTreeTypeDeclaration);
 var
 	type_name: Word;
 	name_length: Word;
@@ -3675,9 +3711,9 @@ end;
 proc elna_parser_type_part();
 var
 	token_kind: Word;
-	parser_node: ^_declaration;
-	result: ^_declaration;
-	current_declaration: ^_declaration;
+	parser_node: ^ElnaTreeDeclaration;
+	result: ^ElnaTreeDeclaration;
+	current_declaration: ^ElnaTreeDeclaration;
 begin
 	result := nil;
 	_skip_empty_lines();
@@ -3714,7 +3750,7 @@ var
 	name: Word;
 	name_length: Word;
 	variable_type: Word;
-	result: ^_variable_declaration;
+	result: ^ElnaTreeVariableDeclaration;
 begin
 	_elna_lexer_read_token(@token_kind);
 
@@ -3727,7 +3763,7 @@ begin
 	_elna_lexer_skip_token();
 
 	variable_type := elna_parser_type_expression();
-	result := malloc(_variable_declaration_size());
+	result := malloc(ElnaTreeVariableDeclaration_size());
 
 	result^.kind := ElnaTreeKind.variable_declaration;
 	result^.next := nil;
@@ -3738,7 +3774,7 @@ begin
 	return result
 end;
 
-proc _elna_tac_variable_declaration(parser_tree: ^_variable_declaration);
+proc _elna_tac_variable_declaration(parser_tree: ^ElnaTreeVariableDeclaration);
 var
 	name: Word;
 	name_length: Word;
@@ -3798,7 +3834,7 @@ begin
 	return result
 end;
 
-proc _elna_tac_type_part(parser_node: ^_declaration);
+proc _elna_tac_type_part(parser_node: ^ElnaTreeDeclaration);
 var
 	result: Word;
 	first_result: Word;
@@ -3844,7 +3880,7 @@ var
 	result: Word;
 	token_kind: Word;
 	variable_node: Word;
-	current_declaration: ^_declaration;
+	current_declaration: ^ElnaTreeDeclaration;
 begin
 	result := 0;
 	_elna_lexer_read_token(@token_kind);
@@ -3879,7 +3915,7 @@ begin
 	return result
 end;
 
-proc _elna_tac_var_part(parser_node: ^_declaration);
+proc _elna_tac_var_part(parser_node: ^ElnaTreeDeclaration);
 var
 	node: Word;
 	current_variable: ^ElnaInstructionList;
@@ -3911,10 +3947,10 @@ end;
 proc elna_parser_module_declaration();
 var
 	parser_node: Word;
-	result: ^_module_declaration;
+	result: ^ElnaTreeModuleDeclaration;
 	token_kind: Word;
 begin
-	result := malloc(_module_declaration_size());
+	result := malloc(ElnaTreeModuleDeclaration_size());
 	result^.kind := ElnaTreeKind.module_declaration;
 
 	(* Skip "program;". *)
@@ -3934,7 +3970,7 @@ end;
 (**
  * Process the source code and print the generated code.
  *)
-proc _elna_tac_module_declaration(parser_node: ^_module_declaration);
+proc _elna_tac_module_declaration(parser_node: ^ElnaTreeModuleDeclaration);
 var
 	data_part: Word;
 	code_part: Word;
@@ -3960,12 +3996,12 @@ begin
 	return elna_instruction_module_create(data_part, code_part)
 end;
 
-proc elna_name_procedure_declaration(parser_node: ^_procedure_declaration);
+proc elna_name_procedure_declaration(parser_node: ^ElnaTreeProcedureDeclaration);
 var
 	new_symbol_table: Word;
 	parameter_counter: Word;
 	symbol_info: Word;
-	current_parameter: ^_declaration;
+	current_parameter: ^ElnaTreeDeclaration;
 begin
 	new_symbol_table := _symbol_table_create();
 	symbol_info := _procedure_info_create(new_symbol_table);
@@ -3985,7 +4021,7 @@ begin
 	_symbol_table_enter(@symbol_table_global, parser_node^.name, parser_node^.length, symbol_info)
 end;
 
-proc elna_type_conditional_statements(parser_node: ^_conditional_statements, symbol_table: Word);
+proc elna_type_conditional_statements(parser_node: ^ElnaTreeConditionalStatements, symbol_table: Word);
 begin
 	.elna_type_conditional_statements_loop;
 	elna_type_binary_expression(parser_node^.condition, symbol_table);
@@ -3997,9 +4033,9 @@ begin
 	end
 end;
 
-proc elna_type_if_statement(parser_node: ^_if_statement, symbol_table: Word);
+proc elna_type_if_statement(parser_node: ^ElnaTreeIfStatement, symbol_table: Word);
 var
-	block: ^_conditional_statements;
+	block: ^ElnaTreeConditionalStatements;
 begin
 	block := parser_node^.conditionals;
 
@@ -4016,7 +4052,7 @@ begin
 	end
 end;
 
-proc elna_type_return_statement(parser_node: ^_return_statement, symbol_table: Word);
+proc elna_type_return_statement(parser_node: ^ElnaTreeReturnStatement, symbol_table: Word);
 begin
 	elna_type_binary_expression(parser_node^.returned, symbol_table)
 end;
@@ -4039,7 +4075,7 @@ begin
 	end
 end;
 
-proc elna_type_assign_statement(parser_node: ^_assign_statement, symbol_table: Word);
+proc elna_type_assign_statement(parser_node: ^ElnaTreeAssignStatement, symbol_table: Word);
 begin
 	elna_type_designator(parser_node^.assignee, symbol_table);
 	elna_type_binary_expression(parser_node^.assignment, symbol_table)
@@ -4059,7 +4095,7 @@ begin
 	end
 end;
 
-proc elna_type_statements(parser_node: ^_statement, symbol_table: Word);
+proc elna_type_statements(parser_node: ^ElnaTreeStatement, symbol_table: Word);
 begin
 	.elna_type_statements_loop;
 	if parser_node <> nil then
@@ -4094,11 +4130,19 @@ begin
 	parser_node^.type_decoration := symbol_info^._type
 end;
 
+proc elna_type_boolean_literal(parser_node: ^ElnaTreeBooleanLiteral);
+var
+	symbol_info: ^_type_info;
+begin
+	symbol_info := _symbol_table_lookup(@symbol_table_global, "Bool", 4);
+	parser_node^.type_decoration := symbol_info^._type
+end;
+
 proc elna_type_nil_literal(parser_node: ^ElnaTreeNilLiteral);
 var
 	symbol_info: ^_type_info;
 begin
-	symbol_info := _symbol_table_lookup(@symbol_table_global, "Word", 4);
+	symbol_info := _symbol_table_lookup(@symbol_table_global, "Pointer", 7);
 	parser_node^.type_decoration := symbol_info^._type
 end;
 
@@ -4131,6 +4175,8 @@ begin
 		elna_type_character_literal(parser_node)
 	elsif parser_node^.kind = ElnaTreeKind.string_literal then
 		elna_type_string_literal(parser_node)
+	elsif parser_node^.kind = ElnaTreeKind.boolean_literal then
+		elna_type_boolean_literal(parser_node)
 	elsif parser_node^.kind = ElnaTreeKind.null then
 		elna_type_nil_literal(parser_node)
 	elsif parser_node^.kind = ElnaTreeKind.variable_expression then
@@ -4250,7 +4296,7 @@ begin
 	end
 end;
 
-proc elna_type_procedure_declaration(parser_node: ^_procedure_declaration);
+proc elna_type_procedure_declaration(parser_node: ^ElnaTreeProcedureDeclaration);
 var
 	procedure_info: ^_procedure_info;
 	symbol_table: Word;
@@ -4261,9 +4307,9 @@ begin
 	elna_type_statements(parser_node^.body, symbol_table)
 end;
 
-proc elna_name_module_declaration(parser_node: ^_module_declaration);
+proc elna_name_module_declaration(parser_node: ^ElnaTreeModuleDeclaration);
 var
-	current_part: ^_declaration;
+	current_part: ^ElnaTreeDeclaration;
 begin
 	current_part := parser_node^.types;
 	.elna_name_module_declaration_type;
@@ -4291,9 +4337,9 @@ begin
 	end
 end;
 
-proc elna_type_module_declaration(parser_node: ^_module_declaration);
+proc elna_type_module_declaration(parser_node: ^ElnaTreeModuleDeclaration);
 var
-	current_part: ^_declaration;
+	current_part: ^ElnaTreeDeclaration;
 begin
 	current_part := parser_node^.types;
 	.elna_type_module_declaration_type;
@@ -4462,14 +4508,28 @@ begin
 	(* Set the table length to 0. *)
 	symbol_table_global := 0;
 
+	(* Enter built-in symbols. *)
 	current_type := malloc(ElnaType_size());
 	current_type^.kind := ElnaTypeKind.primitive;
 	current_type^.size := 4;
-
-	(* Enter built-in symbols. *)
 	current_info := _type_info_create(current_type);
 	_symbol_table_enter(@symbol_table_global, "Word", 4, current_info);
 
+	current_type := malloc(ElnaType_size());
+	current_type^.kind := ElnaTypeKind.primitive;
+	current_type^.size := 4;
+	current_info := _type_info_create(current_type);
+	_symbol_table_enter(@symbol_table_global, "Pointer", 7, current_info);
+
+	current_type := malloc(ElnaType_size());
+	current_type^.kind := ElnaTypeKind.primitive;
+	current_type^.size := 1;
+	current_info := _type_info_create(current_type);
+	_symbol_table_enter(@symbol_table_global, "Bool", 4, current_info);
+
+	current_type := malloc(ElnaType_size());
+	current_type^.kind := ElnaTypeKind.primitive;
+	current_type^.size := 4096;
 	current_info := _type_info_create(current_type);
 	_symbol_table_enter(@symbol_table_global, "Array", 5, current_info)
 end;
@@ -5034,6 +5094,10 @@ begin
 		result := ElnaLexerKind._module
 	elsif string_compare(position_start, token_length, "nil", 3) then
 		result := ElnaLexerKind.null
+	elsif string_compare(position_start, token_length, "true", 4) then
+		result := ElnaLexerKind.boolean
+	elsif string_compare(position_start, token_length, "false", 5) then
+		result := ElnaLexerKind.boolean
 	end;
 	return result
 end;