feat(furc): introduce while loop statement

Refs: #2

furc/include/furc/front/ir_generator.hpp

@@ -27,6 +27,7 @@ public:
     void visit(const ast::function_definition_node& funcDef) override;
     void visit(const ast::return_statement_node& returnStmt) override;
     void visit(const ast::if_statement_node& node) override;
+    void visit(const ast::while_statement_node& node) override;
     void visit(const ast::compound_statement_node& node) override;
     void visit(const ast::string_literal_node& node) override;
     void visit(const ast::integer_literal_node& node) override;
@@ -42,7 +43,7 @@ private:
         }
     }
 
-    furlang::ir::block_index push_block();
+    furlang::ir::block_index push_block(bool validate = true);
 private:
     furlang::ir::module                    m_module;
     std::unique_ptr<furlang::ir::function> m_currentFunction;
@@ -55,4 +56,4 @@ private:
 } // namespace front
 } // namespace furc
 
-#endif // FURC_FRONT_IR_GENERATOR_HPP
+#endif // FURC_FRONT_IR_GENERATOR_HPP

furc/include/furc/front/token.hpp

@@ -145,6 +145,7 @@ enum class keyword_token {
     Return, /**< `return` */
     If,     /**< `if` */
     Else,   /**< `else` */
+    While,  /**< `while` */
 };
 
 static inline std::ostream& operator<<(std::ostream& os, keyword_token keyword) {
@@ -154,6 +155,7 @@ static inline std::ostream& operator<<(std::ostream& os, keyword_token keyword)
     case keyword_token::Return: return os << "return";
     case keyword_token::If: return os << "if";
     case keyword_token::Else: return os << "else";
+    case keyword_token::While: return os << "while";
     }
     return os;
 }
@@ -165,6 +167,7 @@ static inline std::string operator+(const std::string& str, keyword_token keywor
     case keyword_token::Return: return str + "return";
     case keyword_token::If: return str + "if";
     case keyword_token::Else: return str + "else";
+    case keyword_token::While: return str + "while";
     }
     return str;
 }
@@ -377,4 +380,4 @@ using token_r = furlang::result<token, token_error>; /**< Alias to a token resul
 } // namespace front
 } // namespace furc
 
-#endif // FURC_FRONT_TOKEN_HPP
+#endif // FURC_FRONT_TOKEN_HPP