Add string type

source/ast.cc

@@ -7,7 +7,7 @@ namespace elna
 {
 namespace source
 {
-    void empty_visitor::visit(declaration *declaration)
+    void empty_visitor::visit(declaration *)
     {
     }
 
@@ -87,27 +87,31 @@ namespace source
         expression->operand().accept(this);
     }
 
-    void empty_visitor::visit(type_expression *variable)
+    void empty_visitor::visit(type_expression *)
     {
     }
 
-    void empty_visitor::visit(variable_expression *variable)
+    void empty_visitor::visit(variable_expression *)
     {
     }
 
-    void empty_visitor::visit(number_literal<std::int32_t> *number)
+    void empty_visitor::visit(number_literal<std::int32_t> *)
     {
     }
 
-    void empty_visitor::visit(number_literal<double> *number)
+    void empty_visitor::visit(number_literal<double> *)
     {
     }
 
-    void empty_visitor::visit(number_literal<bool> *character)
+    void empty_visitor::visit(number_literal<bool> *)
     {
     }
 
-    void empty_visitor::visit(char_literal *character)
+    void empty_visitor::visit(char_literal *)
+    {
+    }
+
+    void empty_visitor::visit(string_literal *)
     {
     }
 
@@ -313,6 +317,21 @@ namespace source
         return m_character;
     }
 
+    string_literal::string_literal(const struct position position, const std::string& value)
+        : expression(position), m_string(value)
+    {
+    }
+
+    void string_literal::accept(parser_visitor *visitor)
+    {
+        visitor->visit(this);
+    }
+
+    const std::string& string_literal::string() const noexcept
+    {
+        return m_string;
+    }
+
     variable_expression::variable_expression(const struct position position, const std::string& name)
         : expression(position), m_name(name)
     {
@@ -550,6 +569,7 @@ namespace source
             case binary_operator::greater_equal:
                 return ">=";
         }
+        __builtin_unreachable();
     };
 }
 }

source/lexer.ll

@@ -80,6 +80,10 @@ false                   {
                             return yy::parser::make_CHARACTER(
 									std::string(yytext, 1, strlen(yytext) - 2), this->location);
                         }
+\"[^\"]*\"              {
+                            return yy::parser::make_STRING(
+									std::string(yytext, 1, strlen(yytext) - 2), this->location);
+                        }
 \(                      {
                             return yy::parser::make_LEFT_PAREN(this->location);
                         }

source/parser.yy

@@ -60,6 +60,7 @@
 %token <std::int32_t> INTEGER "integer"
 %token <float> FLOAT "float"
 %token <std::string> CHARACTER "character"
+%token <std::string> STRING "string"
 %token <bool> BOOLEAN
 %token IF WHILE DO
 %token CONST VAR PROCEDURE
@@ -76,6 +77,7 @@
 %type <std::unique_ptr<elna::source::number_literal<double>>> float_literal;
 %type <std::unique_ptr<elna::source::number_literal<bool>>> boolean_literal;
 %type <std::unique_ptr<elna::source::char_literal>> character_literal;
+%type <std::unique_ptr<elna::source::string_literal>> string_literal;
 %type <std::unique_ptr<elna::source::constant_definition>> constant_definition;
 %type <std::vector<std::unique_ptr<elna::source::constant_definition>>> constant_definition_part constant_definitions;
 %type <std::unique_ptr<elna::source::declaration>> variable_declaration;
@@ -153,7 +155,11 @@ float_literal: FLOAT
         };
 character_literal: CHARACTER
         {
-            $$ = std::make_unique<elna::source::char_literal>(elna::source::make_position(@1), $1[0]); 
+            $$ = std::make_unique<elna::source::char_literal>(elna::source::make_position(@1), $1.at(0)); 
+        };
+string_literal: STRING
+        {
+            $$ = std::make_unique<elna::source::string_literal>(elna::source::make_position(@1), $1); 
         };
 boolean_literal: BOOLEAN
         {
@@ -194,6 +200,7 @@ pointer:
     | float_literal { $$ = std::move($1); }
     | boolean_literal { $$ = std::move($1); }
     | character_literal { $$ = std::move($1); }
+    | string_literal { $$ = std::move($1); }
     | variable_expression { $$ = std::move($1); }
     | LEFT_PAREN expression RIGHT_PAREN { $$ = std::move($2); }
 summand: