Get rid of the raw pointers in the parser

CMakeLists.txt

@@ -19,10 +19,10 @@ add_executable(elnsh shell/main.cpp
 target_include_directories(elnsh PRIVATE include)
 
 add_executable(elna source/main.cpp
-	source/lexer.cpp include/elna/lexer.hpp
+	source/lexer.cpp include/elna/source/lexer.hpp
+	source/parser.cpp include/elna/source/parser.hpp
 	source/result.cpp include/elna/result.hpp
 	source/riscv.cpp include/elna/riscv.hpp
-	source/parser.cpp include/elna/parser.hpp
 	source/ir.cpp include/elna/ir.hpp
 	source/cl.cpp include/elna/cl.hpp
 )

include/elna/ir.hpp

@@ -1,18 +1,16 @@
 #pragma once
 
-#include "elna/parser.hpp"
+#include "elna/source/parser.hpp"
 
 namespace elna
 {
-    class TransformVisitor final : public ParserVisitor
+    class TransformVisitor final : public source::ParserVisitor
     {
-        void visit(Node *node) override;
+        void visit(source::definition *definition) override;
-        void visit(Definition *definition) override;
+        void visit(source::bang_statement *statement) override;
-        void visit(BangStatement *statement) override;
+        void visit(source::block *block) override;
-        void visit(Block *block) override;
+        void visit(source::integer_literal *number) override;
-        void visit(Expression *expression) override;
+        void visit(source::variable *variable) override;
-        void visit(Number *number) override;
+        void visit(source::binary_expression *binaryExpression) override;
-        void visit(Variable *variable) override;
-        void visit(BinaryExpression *binaryExpression) override;
     };
 }

include/elna/lexer.hpp

@@ -1,115 +0,0 @@
-#pragma once
-
-#include <cstdint>
-#include <string>
-
-#include "elna/result.hpp"
-
-namespace elna
-{
-namespace lex
-{
-    /**
-     * Range over the source text that keeps track of the current position.
-     */
-    struct source
-    {
-        class const_iterator
-        {
-            std::string::const_iterator m_buffer;
-            elna::source::position m_position;
-
-            const_iterator(std::string::const_iterator buffer,
-                    const elna::source::position start_position = elna::source::position());
-
-        public:
-            using iterator_category = std::forward_iterator_tag;
-            using difference_type = ptrdiff_t;
-            using value_type = char;
-            using pointer = const value_type *;
-            using reference = const value_type&;
-
-            const elna::source::position& position() const noexcept;
-
-            reference operator*() const noexcept;
-            pointer operator->() const noexcept;
-            const_iterator& operator++();
-            const_iterator& operator++(int);
-            bool operator==(const const_iterator& that) const noexcept;
-            bool operator!=(const const_iterator& that) const noexcept;
-
-            friend source;
-        };
-
-        source(const std::string& buffer);
-        const_iterator begin() const;
-        const_iterator end() const;
-
-    private:
-        const std::string m_buffer;
-    };
-
-    /**
-     * Union type representing a single token.
-     */
-    struct Token
-    {
-        /**
-         * Token type.
-         */
-        enum class type : std::uint16_t
-        {
-            number = 0,
-            term_operator = 1,
-            let = 2,
-            identifier = 3,
-            equals = 4,
-            var = 5,
-            semicolon = 6,
-            left_paren = 7,
-            right_paren = 8,
-            bang = 9,
-            dot = 10,
-            comma = 11,
-            factor_operator = 12,
-        };
-
-        /**
-         * Type of the token value.
-         */
-        union Value
-        {
-            std::int32_t number;
-            const char *identifier;
-        };
-
-        Token(type of, elna::source::position position);
-        Token(type of, std::int32_t value, elna::source::position position);
-        Token(type of, const char *value, elna::source::position position);
-        Token(const Token& that);
-        Token(Token&& that);
-        ~Token();
-
-        Token& operator=(const Token& that);
-        Token& operator=(Token&& that);
-
-        type of() const noexcept;
-        const char *identifier() const noexcept;
-        std::int32_t number() const noexcept;
-        const elna::source::position& position() const noexcept;
-
-    private:
-        type m_type;
-        Value m_value;
-        elna::source::position m_position;
-    };
-
-    /**
-     * Split the source into tokens.
-     *
-     * \param buffer Source text.
-     * \return Tokens or error.
-     */
-    elna::source::result<std::vector<Token>> lex(const char *buffer);
-}
-}

include/elna/parser.hpp

@@ -1,125 +0,0 @@
-#pragma once
-
-#include <cstddef>
-#include <cstdint>
-#include <elna/lexer.hpp>
-
-namespace elna
-{
-    enum class BinaryOperator
-    {
-        sum,
-        subtraction,
-        multiplication,
-        division
-    };
-
-    class Node;
-    class Definition;
-    class BangStatement;
-    class Block;
-    class Expression;
-    class BinaryExpression;
-    class Variable;
-    class Number;
-
-    struct ParserVisitor
-    {
-        virtual void visit(Node *) = 0;
-        virtual void visit(Definition *) = 0;
-        virtual void visit(BangStatement *) = 0;
-        virtual void visit(Block *) = 0;
-        virtual void visit(Expression *) = 0;
-        virtual void visit(BinaryExpression *) = 0;
-        virtual void visit(Variable *) = 0;
-        virtual void visit(Number *) = 0;
-    };
-
-    /**
-     * AST node.
-     */
-    class Node
-    {
-    public:
-        virtual void accept(ParserVisitor *) = 0;
-    };
-
-    class Statement : public Node
-    {
-    };
-
-    /**
-     * Constant definition.
-     */
-    class Definition : public Node
-    {
-    public:
-        Number *number;
-        const char *identifier;
-
-        virtual void accept(ParserVisitor *visitor) override;
-    };
-
-    class BangStatement : public Statement
-    {
-    public:
-        Expression *expression;
-
-        virtual void accept(ParserVisitor *visitor) override;
-    };
-
-    /**
-     * Block.
-     */
-    class Block : public Node
-    {
-    public:
-        Definition** definitions{ nullptr };
-        size_t definitionsLength{ 0 };
-        Statement *statement{ nullptr };
-
-        virtual void accept(ParserVisitor *visitor) override;
-    };
-
-    class Expression : public Node
-    {
-    public:
-        virtual void accept(ParserVisitor *visitor) override;
-    };
-
-    class Number : public Expression
-    {
-    public:
-        std::int32_t value;
-
-        virtual void accept(ParserVisitor *visitor) override;
-    };
-
-    class Variable : public Expression
-    {
-    public:
-        const char *identifier;
-
-        virtual void accept(ParserVisitor *visitor) override;
-    };
-
-    class BinaryExpression : public Expression
-    {
-    public:
-        Expression *lhs, *rhs;
-        BinaryOperator _operator;
-
-        BinaryExpression(Expression *lhs, Expression *rhs, unsigned char);
-
-        virtual void accept(ParserVisitor *visitor) override;
-    };
-
-    Expression *parseFactor(lex::Token **tokens, std::size_t *length);
-    Expression *parseTerm(lex::Token **tokens, std::size_t *length);
-    Expression *parseExpression(lex::Token **tokens, std::size_t *length);
-    Definition *parseDefinition(lex::Token **tokens, std::size_t *length);
-    Statement *parseStatement(lex::Token **tokens, std::size_t *length);
-    Definition **parseDefinitions(lex::Token **tokens, std::size_t *length, std::size_t *resultLength);
-    Block *parseBlock(lex::Token **tokens, std::size_t *length);
-    Block *parse(lex::Token *tokenStream, std::size_t length);
-}

include/elna/riscv.hpp

@@ -1,7 +1,8 @@
 #pragma once
 
 #include <cstdint>
-#include "elna/parser.hpp"
+#include <unordered_map>
+#include "elna/source/parser.hpp"
 #include "elna/result.hpp"
 
 namespace elna
@@ -141,7 +142,7 @@ namespace elna
         std::uint32_t instruction{ 0 };
     };
 
-    class RiscVVisitor : public ParserVisitor
+    class RiscVVisitor : public source::ParserVisitor
     {
     public:
         Instruction *instructions;
@@ -149,19 +150,15 @@ namespace elna
         bool registerInUse{ true };
         std::uint32_t variableCounter = 1;
         Reference references[3];
-        std::int32_t *constValues{ nullptr };
+        std::unordered_map<std::string, std::int32_t> constants;
-        const char **constNames{ nullptr };
-        std::size_t constCount{ 0 };
 
-        virtual void visit(Node *) override;
+        virtual void visit(source::definition *definition) override;
-        virtual void visit(Definition *definition) override;
+        virtual void visit(source::bang_statement *statement) override;
-        virtual void visit(BangStatement *statement) override;
+        virtual void visit(source::block *block) override;
-        virtual void visit(Block *block) override;
+        virtual void visit(source::variable *variable) override;
-        virtual void visit(Expression *operand) override;
+        virtual void visit(source::integer_literal *number) override;
-        virtual void visit(Variable *variable) override;
+        virtual void visit(source::binary_expression *expression) override;
-        virtual void visit(Number *number) override;
-        virtual void visit(BinaryExpression *expression) override;
     };
 
-    Symbol writeNext(Block *ast);
+    Symbol writeNext(source::block *ast);
 }

include/elna/source/lexer.hpp

@@ -0,0 +1,116 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+
+#include "elna/result.hpp"
+
+namespace elna
+{
+namespace source
+{
+    /**
+     * Range over the source text that keeps track of the current position.
+     */
+    class text_iterator
+    {
+        std::string::const_iterator m_buffer;
+        elna::source::position m_position;
+
+        text_iterator(std::string::const_iterator buffer,
+                const elna::source::position start_position = elna::source::position());
+
+    public:
+        using iterator_category = std::forward_iterator_tag;
+        using difference_type = ptrdiff_t;
+        using value_type = char;
+        using pointer = const value_type *;
+        using reference = const value_type&;
+
+        const elna::source::position& position() const noexcept;
+
+        reference operator*() const noexcept;
+        pointer operator->() const noexcept;
+        text_iterator& operator++();
+        text_iterator& operator++(int);
+        bool operator==(const text_iterator& that) const noexcept;
+        bool operator!=(const text_iterator& that) const noexcept;
+
+        friend std::pair<text_iterator, text_iterator> text_iterators(const std::string& buffer);
+    };
+
+    std::pair<text_iterator, text_iterator>
+    text_iterators(const std::string &buffer);
+
+    /**
+     * Union type representing a single token.
+     */
+    struct token
+    {
+        /**
+         * Token type.
+         */
+        enum class type : std::uint16_t
+        {
+            number = 0,
+            term_operator = 1,
+            let = 2,
+            identifier = 3,
+            equals = 4,
+            var = 5,
+            semicolon = 6,
+            left_paren = 7,
+            right_paren = 8,
+            bang = 9,
+            dot = 10,
+            comma = 11,
+            factor_operator = 12,
+        };
+
+        /**
+         * Type of the token value.
+         */
+        union value
+        {
+            value();
+            value(std::int32_t value);
+            value(const std::string& value);
+            ~value();
+
+            std::nullptr_t nil;
+            std::int32_t number;
+            std::string identifier;
+        };
+
+        token(type of, elna::source::position position);
+        token(type of, std::int32_t value, const elna::source::position position);
+        token(type of, const std::string& value, const elna::source::position position);
+        token(const token& that);
+        token(token&& that);
+        ~token();
+
+        token& operator=(const token& that);
+        token& operator=(token&& that);
+
+        type of() const noexcept;
+        const std::string& identifier() const;
+        std::int32_t number() const;
+        const elna::source::position& position() const noexcept;
+
+    private:
+        type m_type;
+        value m_value;
+        elna::source::position m_position;
+
+        bool has_identifier() const noexcept;
+    };
+
+    /**
+     * Split the source into tokens.
+     *
+     * \param buffer Source text.
+     * \return Tokens or error.
+     */
+    elna::source::result<std::vector<token>> lex(const std::string& buffer);
+}
+}

include/elna/source/parser.hpp

@@ -0,0 +1,153 @@
+#pragma once
+
+#include <cstdint>
+#include <memory>
+#include <elna/source/lexer.hpp>
+
+namespace elna
+{
+namespace source
+{
+    enum class binary_operator
+    {
+        sum,
+        subtraction,
+        multiplication,
+        division
+    };
+
+    class definition;
+    class bang_statement;
+    class block;
+    class binary_expression;
+    class variable;
+    class integer_literal;
+
+    struct ParserVisitor
+    {
+        virtual void visit(definition *) = 0;
+        virtual void visit(bang_statement *) = 0;
+        virtual void visit(block *) = 0;
+        virtual void visit(binary_expression *) = 0;
+        virtual void visit(variable *) = 0;
+        virtual void visit(integer_literal *) = 0;
+    };
+
+    /**
+     * AST node.
+     */
+    class node
+    {
+    public:
+        virtual void accept(ParserVisitor *) = 0;
+    };
+
+    class statement : public node
+    {
+    };
+
+    class expression : public node
+    {
+    };
+
+    /**
+     * Constant definition.
+     */
+    class definition : public node
+    {
+        std::string m_identifier;
+        std::unique_ptr<integer_literal> m_body;
+
+    public:
+        definition(std::string&& identifier, std::unique_ptr<integer_literal>&& body);
+        virtual void accept(ParserVisitor *visitor) override;
+
+        std::string& identifier() noexcept;
+        integer_literal& body();
+    };
+
+    class bang_statement : public statement
+    {
+        std::unique_ptr<expression> m_body;
+
+    public:
+        bang_statement(std::unique_ptr<expression>&& body);
+        virtual void accept(ParserVisitor *visitor) override;
+
+        expression& body();
+    };
+
+    /**
+     * Block.
+     */
+    class block : public node
+    {
+        std::unique_ptr<statement> m_body;
+        std::vector<std::unique_ptr<definition>> m_definitions;
+
+    public:
+        block(std::vector<std::unique_ptr<definition>>&& definitions, std::unique_ptr<statement>&& body);
+        virtual void accept(ParserVisitor *visitor) override;
+
+        statement& body();
+        std::vector<std::unique_ptr<definition>>& definitions() noexcept;
+    };
+
+    class integer_literal : public expression
+    {
+        std::int32_t m_number;
+
+    public:
+        integer_literal(const std::int32_t value);
+        virtual void accept(ParserVisitor *visitor) override;
+
+        std::int32_t number() const noexcept;
+    };
+
+    class variable : public expression
+    {
+        std::string m_name;
+
+    public:
+        variable(const std::string& name);
+        virtual void accept(ParserVisitor *visitor) override;
+
+        const std::string& name() const noexcept;
+    };
+
+    class binary_expression : public expression
+    {
+        std::unique_ptr<expression> m_lhs;
+        std::unique_ptr<expression> m_rhs;
+        binary_operator m_operator;
+
+    public:
+        binary_expression(std::unique_ptr<expression>&& lhs,
+                std::unique_ptr<expression>&& rhs, const unsigned char operation);
+
+        virtual void accept(ParserVisitor *visitor) override;
+        expression& lhs();
+        expression& rhs();
+        binary_operator operation() const noexcept;
+    };
+
+    struct parser
+    {
+        parser(const std::vector<token>& tokens);
+
+        std::unique_ptr<block> parse();
+
+    private:
+        std::unique_ptr<expression> parse_factor();
+        std::unique_ptr<expression> parse_term();
+        std::unique_ptr<expression> parse_expression();
+        std::unique_ptr<definition> parse_definition();
+        std::unique_ptr<statement> parse_bang_statement();
+        std::vector<std::unique_ptr<definition>> parse_definitions();
+        std::unique_ptr<block> parse_block();
+
+        std::vector<token>::const_iterator tokens;
+        std::vector<token>::const_iterator end;
+    };
+}
+}

source/cl.cpp

@@ -41,7 +41,7 @@ namespace elna
             return 3;
         }
         size_t tokensCount{ 0 };
-        auto lex_result = lex::lex(sourceText);
+        auto lex_result = source::lex(sourceText);
         free(sourceText);
         if (lex_result.has_errors())
         {
@@ -51,12 +51,12 @@ namespace elna
             }
             return 1;
         }
-        auto ast = parse(lex_result.success().data(), tokensCount);
+        auto ast = source::parser(lex_result.success()).parse();
         if (ast == nullptr)
         {
             return 2;
         }
-        auto program = writeNext(ast);
+        auto program = writeNext(ast.get());
 
         // Create code section
         ELFIO::section* text_sec = writer.sections.add(".text");

source/ir.cpp

@@ -4,42 +4,32 @@
 
 namespace elna
 {
-    void TransformVisitor::visit(Node *node)
+    void TransformVisitor::visit(source::definition *definition)
     {
         assert(false);
     }
 
-    void TransformVisitor::visit(Definition *definition)
+    void TransformVisitor::visit(source::bang_statement *statement)
     {
         assert(false);
     }
 
-    void TransformVisitor::visit(BangStatement *statement)
+    void TransformVisitor::visit(source::block *block)
     {
         assert(false);
     }
 
-    void TransformVisitor::visit(Block *block)
+    void TransformVisitor::visit(source::integer_literal *number)
     {
         assert(false);
     }
 
-    void TransformVisitor::visit(Expression *expression)
+    void TransformVisitor::visit(source::variable *variable)
     {
         assert(false);
     }
 
-    void TransformVisitor::visit(Number *number)
+    void TransformVisitor::visit(source::binary_expression *binaryExpression)
-    {
-        assert(false);
-    }
-
-    void TransformVisitor::visit(Variable *variable)
-    {
-        assert(false);
-    }
-
-    void TransformVisitor::visit(BinaryExpression *binaryExpression)
     {
         assert(false);
     }

source/lexer.cpp

@@ -1,54 +1,42 @@
-#include "elna/lexer.hpp"
+#include "elna/source/lexer.hpp"
-
+#include <variant>
-#include <cstring>
 
 namespace elna
 {
-namespace lex
+namespace source
 {
     using source_position = elna::source::position;
     using source_error = elna::source::error;
-    using source_result = elna::source::result<std::vector<Token>>;
+    using source_result = elna::source::result<std::vector<token>>;
 
-    source::source(const std::string& buffer)
+    std::pair<text_iterator, text_iterator> text_iterators(const std::string &buffer)
-        : m_buffer(buffer)
     {
+        return std::make_pair<>(text_iterator(std::cbegin(buffer)),
+                text_iterator(std::cend(buffer), position{0, 0}));
     }
 
-    source::const_iterator source::begin() const
+    text_iterator::text_iterator(std::string::const_iterator buffer,
-    {
-        return source::const_iterator(std::cbegin(m_buffer));
-    }
-
-    source::const_iterator source::end() const
-    {
-        source_position end_position{ 0, 0 };
-
-        return source::const_iterator(std::cend(m_buffer), end_position);
-    }
-
-    source::const_iterator::const_iterator(std::string::const_iterator buffer,
             const source_position start_position)
         : m_buffer(buffer), m_position(start_position)
     {
     }
 
-    const source_position& source::const_iterator::position() const noexcept
+    const source_position& text_iterator::position() const noexcept
     {
         return this->m_position;
     }
 
-    source::const_iterator::reference source::const_iterator::operator*() const noexcept
+    text_iterator::reference text_iterator::operator*() const noexcept
     {
         return *m_buffer;
     }
 
-    source::const_iterator::pointer source::const_iterator::operator->() const noexcept
+    text_iterator::pointer text_iterator::operator->() const noexcept
     {
         return m_buffer.base();
     }
 
-    source::const_iterator& source::const_iterator::operator++()
+    text_iterator& text_iterator::operator++()
     {
         if (*this->m_buffer == '\n')
         {
@@ -64,129 +52,156 @@ namespace lex
         return *this;
     }
 
-    source::const_iterator& source::const_iterator::operator++(int)
+    text_iterator& text_iterator::operator++(int)
     {
         auto tmp = *this;
         ++(*this);
         return *this;
     }
 
-    bool source::const_iterator::operator==(const source::const_iterator& that) const noexcept
+    bool text_iterator::operator==(const text_iterator& that) const noexcept
     {
         return this->m_buffer == that.m_buffer;
     }
 
-    bool source::const_iterator::operator!=(const source::const_iterator& that) const noexcept
+    bool text_iterator::operator!=(const text_iterator& that) const noexcept
     {
         return !(*this == that);
     }
 
-    Token::Token(const type of, const char *value, source_position position)
+    token::value::value()
-        : m_type(of), m_position(position)
+        : nil(nullptr)
     {
-        std::size_t value_length = strlen(value);
-        char *buffer = reinterpret_cast<char *>(malloc(value_length + 1));
-
-        std::memcpy(buffer, value, value_length);
-        buffer[value_length] = 0;
-
-        m_value.identifier = buffer;
     }
 
-    Token::Token(const type of, std::int32_t number, source_position position)
+    token::value::value(std::int32_t value)
-        : m_type(of), m_position(position)
+        : number(value)
     {
-        m_value.number = number;
     }
 
-    Token::Token(const type of, source_position position)
+    token::value::value(const std::string& value)
+        : identifier(value)
+    {
+    }
+
+    token::value::~value()
+    {
+    }
+
+    token::token(const type of, const std::string& value, const source_position position)
+        : m_type(of), m_value(value), m_position(position)
+    {
+    }
+
+    token::token(const type of, std::int32_t number, const source_position position)
+        : m_type(of), m_value(number), m_position(position)
+    {
+    }
+
+    token::token(const type of, source_position position)
         : m_type(of), m_position(position)
     {
     }
 
-    Token::Token(const Token& that)
+    token::token(const token& that)
         : m_type(that.of()), m_position(that.position())
     {
         *this = that;
     }
 
-    Token::Token(Token&& that)
+    token::token(token&& that)
         : m_type(that.of()), m_position(that.position())
     {
         *this = std::move(that);
     }
 
-    Token::~Token()
+    token::~token()
     {
         if (m_type == type::identifier || m_type == type::term_operator || m_type == type::factor_operator)
         {
-            std::free(const_cast<char*>(m_value.identifier));
+            m_value.identifier.~basic_string();
         }
     }
 
-    Token& Token::operator=(const Token& that)
+    token& token::operator=(const token& that)
     {
         m_type = that.of();
         m_position = that.position();
-        if (that.of() == type::identifier || that.of() == type::term_operator || m_type == type::factor_operator)
+        if (that.has_identifier())
-        {
-            std::size_t value_length = strlen(that.identifier());
-            char *buffer = reinterpret_cast<char *>(malloc(value_length + 1));
-
-            std::memcpy(buffer, that.identifier(), value_length);
-            buffer[value_length] = 0;
-
-            m_value.identifier = buffer;
-        }
-        else if (that.of() == type::number)
-        {
-            m_value.number = that.number();
-        }
-        return *this;
-    }
-
-    Token& Token::operator=(Token&& that)
-    {
-        m_type = that.of();
-        m_position = that.position();
-        if (that.of() == type::identifier || that.of() == type::term_operator || that.of() == type::factor_operator)
         {
             m_value.identifier = that.identifier();
-            that.m_value.identifier = nullptr;
         }
         else if (that.of() == type::number)
         {
             m_value.number = that.number();
         }
+        else
+        {
+            m_value.nil = nullptr;
+        }
         return *this;
     }
 
-    Token::type Token::of() const noexcept
+    token& token::operator=(token&& that)
+    {
+        m_type = that.of();
+        m_position = that.position();
+        if (that.has_identifier())
+        {
+            m_value.identifier = std::move(that.identifier());
+        }
+        else if (that.of() == type::number)
+        {
+            m_value.number = that.number();
+        }
+        else
+        {
+            m_value.nil = nullptr;
+        }
+        return *this;
+    }
+
+    token::type token::of() const noexcept
     {
         return m_type;
     }
 
-    const char *Token::identifier() const noexcept
+    const std::string& token::identifier() const
     {
+        if (!has_identifier())
+        {
+            throw std::bad_variant_access();
+        }
         return m_value.identifier;
     }
 
-    std::int32_t Token::number() const noexcept
+    std::int32_t token::number() const
     {
+        if (of() != type::number)
+        {
+            throw std::bad_variant_access();
+        }
         return m_value.number;
     }
 
-    const source_position& Token::position() const noexcept
+    const source_position& token::position() const noexcept
     {
         return m_position;
     }
 
-    source_result lex(const char *buffer)
+    bool token::has_identifier() const noexcept
     {
-        std::vector<Token> tokens;
+        return of() == type::identifier
-        source input{ buffer };
+            || of() == type::term_operator
+            || of() == type::factor_operator;
+    }
 
-        for (auto iterator = input.begin(); iterator != input.end();)
+    source_result lex(const std::string& buffer)
+    {
+        std::vector<token> tokens;
+        auto [iterator, text_end] = text_iterators(buffer);
+
+        while (iterator != text_end)
         {
             if (*iterator == ' ' || *iterator == '\n')
             {
@@ -194,59 +209,59 @@ namespace lex
             else if (std::isdigit(*iterator))
             {
                 tokens.emplace_back(
-                        Token::type::number,
+                        token::type::number,
                         static_cast<std::int32_t>(*iterator - '0'),
                         iterator.position()
                 );
             }
             else if (*iterator == '=')
             {
-                tokens.emplace_back(Token::type::equals, iterator.position());
+                tokens.emplace_back(token::type::equals, iterator.position());
             }
             else if (*iterator == '(')
             {
-                tokens.emplace_back(Token::type::left_paren, iterator.position());
+                tokens.emplace_back(token::type::left_paren, iterator.position());
             }
             else if (*iterator == ')')
             {
-                tokens.emplace_back(Token::type::right_paren, iterator.position());
+                tokens.emplace_back(token::type::right_paren, iterator.position());
             }
             else if (*iterator == ';')
             {
-                tokens.emplace_back(Token::type::semicolon, iterator.position());
+                tokens.emplace_back(token::type::semicolon, iterator.position());
             }
             else if (*iterator == ',')
             {
-                tokens.emplace_back(Token::type::comma, iterator.position());
+                tokens.emplace_back(token::type::comma, iterator.position());
             }
             else if (*iterator == '!')
             {
-                tokens.emplace_back(Token::type::bang, iterator.position());
+                tokens.emplace_back(token::type::bang, iterator.position());
             }
             else if (*iterator == '.')
             {
-                tokens.emplace_back(Token::type::dot, iterator.position());
+                tokens.emplace_back(token::type::dot, iterator.position());
             }
             else if (std::isalpha(*iterator))
             {
                 std::string word;
                 auto i = iterator;
-                while (i != input.end() && std::isalpha(*i))
+                while (i != text_end && std::isalpha(*i))
                 {
                     word.push_back(*i);
                     ++i;
                 }
                 if (word == "const")
                 {
-                    tokens.emplace_back(Token::type::let, iterator.position());
+                    tokens.emplace_back(token::type::let, iterator.position());
                 }
                 else if (word == "var")
                 {
-                    tokens.emplace_back(Token::type::var, iterator.position());
+                    tokens.emplace_back(token::type::var, iterator.position());
                 }
                 else
                 {
-                    tokens.emplace_back(Token::type::identifier, word.c_str(), iterator.position());
+                    tokens.emplace_back(token::type::identifier, word.c_str(), iterator.position());
                 }
                 iterator = i;
                 continue;
@@ -255,13 +270,13 @@ namespace lex
             {
                 std::string _operator{ *iterator };
 
-                tokens.emplace_back(Token::type::term_operator, _operator.c_str(), iterator.position());
+                tokens.emplace_back(token::type::term_operator, _operator.c_str(), iterator.position());
             }
             else if (*iterator == '*' || *iterator == '/')
             {
                 std::string _operator{ *iterator };
 
-                tokens.emplace_back(Token::type::factor_operator, _operator.c_str(), iterator.position());
+                tokens.emplace_back(token::type::factor_operator, _operator.c_str(), iterator.position());
             }
             else
             {

source/parser.cpp

@@ -1,254 +1,294 @@
-#include "elna/parser.hpp"
+#include "elna/source/parser.hpp"
 #include <stdexcept>
 
 namespace elna
+{
+namespace source
 {
     /**
      * AST node.
      */
-    void Node::accept(ParserVisitor *)
+    void node::accept(ParserVisitor *)
     {
     }
 
-    void Definition::accept(ParserVisitor *visitor)
+    definition::definition(std::string&& identifier, std::unique_ptr<integer_literal>&& body)
+        : m_identifier(std::move(identifier)), m_body(std::move(body))
+    {
+    }
+
+    void definition::accept(ParserVisitor *visitor)
     {
         visitor->visit(this);
     }
 
-    void Block::accept(ParserVisitor *visitor)
+    std::string& definition::identifier() noexcept
+    {
+        return m_identifier;
+    }
+
+    integer_literal& definition::body()
+    {
+        return *m_body;
+    }
+
+    block::block(std::vector<std::unique_ptr<definition>>&& definitions, std::unique_ptr<statement>&& body)
+        : m_definitions(std::move(definitions)), m_body(std::move(body))
+    {
+    }
+
+    void block::accept(ParserVisitor *visitor)
     {
         visitor->visit(this);
     }
 
-    void Expression::accept(ParserVisitor *visitor)
+    statement& block::body()
+    {
+        return *m_body;
+    }
+
+    std::vector<std::unique_ptr<definition>>& block::definitions() noexcept
+    {
+        return m_definitions;
+    }
+
+    integer_literal::integer_literal(const std::int32_t value)
+        : m_number(value)
+    {
+    }
+
+    void integer_literal::accept(ParserVisitor *visitor)
     {
         visitor->visit(this);
     }
 
-    void Number::accept(ParserVisitor *visitor)
+    std::int32_t integer_literal::number() const noexcept
+    {
+        return m_number;
+    }
+
+    variable::variable(const std::string& name)
+        : m_name(name)
+    {
+    }
+
+    void variable::accept(ParserVisitor *visitor)
     {
         visitor->visit(this);
     }
 
-    void Variable::accept(ParserVisitor *visitor)
+    const std::string& variable::name() const noexcept
     {
-        visitor->visit(this);
+        return m_name;
     }
 
-    BinaryExpression::BinaryExpression(Expression *lhs, Expression *rhs, unsigned char _operator)
+    binary_expression::binary_expression(std::unique_ptr<expression>&& lhs,
+            std::unique_ptr<expression>&& rhs, const unsigned char operation)
+        : m_lhs(std::move(lhs)), m_rhs(std::move(rhs))
     {
-        this->lhs = lhs;
+        switch (operation)
-        this->rhs = rhs;
-
-        switch (_operator)
         {
             case '+':
-                this->_operator = BinaryOperator::sum;
+                this->m_operator = binary_operator::sum;
                 break;
             case '-': 
-                this->_operator = BinaryOperator::subtraction;
+                this->m_operator = binary_operator::subtraction;
                 break;
             case '*':
-                this->_operator = BinaryOperator::multiplication;
+                this->m_operator = binary_operator::multiplication;
                 break;
             case '/':
-                this->_operator = BinaryOperator::division;
+                this->m_operator = binary_operator::division;
                 break;
             default:
                 throw std::logic_error("Invalid binary operator");
         }
     }
 
-    void BinaryExpression::accept(ParserVisitor *visitor)
+    void binary_expression::accept(ParserVisitor *visitor)
     {
         visitor->visit(this);
     }
 
-    void BangStatement::accept(ParserVisitor *visitor)
+    expression& binary_expression::lhs()
+    {
+        return *m_lhs;
+    }
+
+    expression& binary_expression::rhs()
+    {
+        return *m_rhs;
+    }
+
+    binary_operator binary_expression::operation() const noexcept
+    {
+        return m_operator;
+    }
+
+    bang_statement::bang_statement(std::unique_ptr<expression>&& body)
+        : m_body(std::move(body))
+    {
+    }
+
+    void bang_statement::accept(ParserVisitor *visitor)
     {
         visitor->visit(this);
     }
 
-    Block *parse(lex::Token *tokenStream, std::size_t length)
+    expression& bang_statement::body()
     {
-        return parseBlock(&tokenStream, &length);
+        return *m_body;
     }
 
-    Expression *parseFactor(lex::Token **tokens, size_t *length)
+    parser::parser(const std::vector<token>& tokens)
+        : tokens(tokens.cbegin()), end(tokens.cend())
     {
-        if ((*tokens)[0].of() == lex::Token::type::identifier)
-        {
-            auto variable = new Variable();
-            variable->identifier = (*tokens)[0].identifier();
-            ++(*tokens);
-            --(*length);
-            return variable;
     }
-        else if ((*tokens)[0].of() == lex::Token::Token::type::number)
+
+    std::unique_ptr<block> parser::parse()
     {
-            auto number = new Number();
+        return parse_block();
-            number->value = (*tokens)[0].number();
-            ++(*tokens);
-            --(*length);
-            return number;
     }
-        else if ((*tokens)[0].of() == lex::Token::type::left_paren)
+
+    std::unique_ptr<expression> parser::parse_factor()
     {
-            ++(*tokens);
+        if (tokens->of() == source::token::type::identifier)
-            --(*length);
+        {
+            auto result = std::make_unique<variable>(tokens->identifier());
+            ++tokens;
+            return result;
+        }
+        else if (tokens->of() == source::token::token::type::number)
+        {
+            auto result = std::make_unique<integer_literal>(tokens->number());
+            ++tokens;
+            return result;
+        }
+        else if (tokens->of() == source::token::type::left_paren)
+        {
+            ++tokens;
 
-            auto expression = parseExpression(tokens, length);
+            auto expression = parse_expression();
 
-            ++(*tokens);
+            ++tokens;
-            --(*length);
 
             return expression;
         }
         return nullptr;
     }
 
-    Expression *parseTerm(lex::Token **tokens, size_t *length)
+    std::unique_ptr<expression> parser::parse_term()
     {
-        auto lhs = parseFactor(tokens, length);
+        auto lhs = parse_factor();
-        if (lhs == nullptr || *length == 0 || (*tokens)[0].of() != lex::Token::type::factor_operator)
+        if (lhs == nullptr || tokens == end || tokens->of() != source::token::type::factor_operator)
         {
             return lhs;
         }
-        auto _operator = (*tokens)[0].identifier()[0];
+        auto _operator = tokens->identifier()[0];
-        ++(*tokens);
+        ++tokens;
-        --(*length);
 
-        auto rhs = parseFactor(tokens, length);
+        auto rhs = parse_factor();
         if (rhs != nullptr)
         {
-            return new BinaryExpression(lhs, rhs, _operator);
+            return std::make_unique<binary_expression>(std::move(lhs),
+                    std::move(rhs), _operator);
         }
         return nullptr;
     }
 
-    Expression *parseExpression(lex::Token **tokens, size_t *length)
+    std::unique_ptr<expression> parser::parse_expression()
     {
-        auto term = parseTerm(tokens, length);
+        auto term = parse_term();
-        if (term == nullptr || *length == 0 || (*tokens)[0].of() != lex::Token::type::term_operator)
+        if (term == nullptr || tokens == end || tokens->of() != source::token::type::term_operator)
         {
             return term;
         }
-        auto _operator = (*tokens)[0].identifier()[0];
+        auto _operator = tokens->identifier()[0];
-        ++(*tokens);
+        ++tokens;
-        --(*length);
 
-        auto expression = parseExpression(tokens, length);
+        auto rhs = parse_expression();
 
-        if (expression != nullptr)
+        if (rhs != nullptr)
         {
-            return new BinaryExpression(term, expression, _operator);
+            return std::make_unique<binary_expression>(std::move(term),
+                    std::move(rhs), _operator);
         }
         return nullptr;
     }
 
-    Definition *parseDefinition(lex::Token **tokens, size_t *length)
+    std::unique_ptr<definition> parser::parse_definition()
     {
-        auto definition = new Definition();
+        std::string definition_identifier = tokens->identifier(); // Copy.
-        definition->identifier = (*tokens)[0].identifier(); // Copy.
 
-        ++(*tokens);
+        ++tokens;
-        ++(*tokens); // Skip the equals sign.
+        ++tokens; // Skip the equals sign.
-        *length -= 2;
 
-        if ((*tokens)[0].of() == lex::Token::type::number)
+        if (tokens->of() == source::token::type::number)
         {
-            auto number = new Number();
+            auto result = std::make_unique<definition>(std::move(definition_identifier),
-            number->value = (*tokens)[0].number();
+                    std::make_unique<integer_literal>(tokens->number()));
-            definition->number = number;
+            ++tokens;
-            ++(*tokens);
+            return result;
-            --(*length);
-            return definition;
         }
         return nullptr;
     }
 
-    Statement *parseStatement(lex::Token **tokens, std::size_t *length)
+    std::unique_ptr<statement> parser::parse_bang_statement()
     {
-        if ((*tokens)[0].of() == lex::Token::type::bang)
+        if (tokens->of() == source::token::type::bang)
         {
-            ++(*tokens);
+            ++tokens;
-            --(*length);
+            auto bang_body = parse_expression();
-            auto statement = new BangStatement();
+            if (bang_body != nullptr)
-            auto expression = parseExpression(tokens, length);
-            if (expression != nullptr)
             {
-                statement->expression = expression;
+                return std::make_unique<bang_statement>(std::move(bang_body));
             }
-            else
-            {
-                return nullptr;
-            }
-            return statement;
         }
         return nullptr;
     }
 
-    Definition **parseDefinitions(lex::Token **tokens, size_t *length, size_t *resultLength)
+    std::vector<std::unique_ptr<definition>> parser::parse_definitions()
     {
-        ++(*tokens); // Skip const.
+        ++tokens; // Skip const.
-        --(*length);
 
-        Definition **definitions;
+        std::vector<std::unique_ptr<definition>> definitions;
-        *resultLength = 0;
 
-        while (*length != 0)
+        while (tokens != end)
         {
-            auto definition = parseDefinition(tokens, length);
+            auto parsed_definition = parse_definition();
-            if (definition == nullptr)
+            if (parsed_definition == nullptr)
             {
-                return nullptr;
+                return definitions;
             }
-            definitions = reinterpret_cast<Definition **>(
+            definitions.push_back(std::move(parsed_definition));
-                    realloc(definitions, (*resultLength + 1) * sizeof(Definition*)));
-            definitions[(*resultLength)++] = definition;
 
-            if ((*tokens)[0].of() == lex::Token::type::semicolon)
+            if (tokens->of() == source::token::type::semicolon)
             {
                 break;
             }
-            if ((*tokens)[0].of() == lex::Token::type::comma)
+            if (tokens->of() == source::token::type::comma)
             {
-                ++(*tokens);
+                ++tokens;
-                --(*length);
             }
         }
 
         return definitions;
     }
 
-    Block *parseBlock(lex::Token **tokens, std::size_t *length)
+    std::unique_ptr<block> parser::parse_block()
     {
-        auto block = new Block();
+        std::vector<std::unique_ptr<definition>> definitions;
-        if ((*tokens)[0].of() == lex::Token::type::let)
+        if (tokens->of() == source::token::type::let)
         {
-            size_t length_ = 0;
+            definitions = parse_definitions();
-            auto constDefinitions = parseDefinitions(tokens, length, &length_);
+            ++tokens;
-            if (constDefinitions != nullptr)
-            {
-                block->definitionsLength = length_;
-                block->definitions = constDefinitions;
         }
-            else
+        auto parsed_statement = parse_bang_statement();
+        if (parsed_statement == nullptr)
         {
             return nullptr;
         }
-            ++(*tokens);
+        return std::make_unique<block>(std::move(definitions), std::move(parsed_statement));
-            --(*length);
+    }
-        }
-        auto statement = parseStatement(tokens, length);
-        if (statement != nullptr)
-        {
-            block->statement = statement;
-        }
-        else
-        {
-            return nullptr;
-        }
-        return block;
 }
 }

source/riscv.cpp

@@ -1,4 +1,3 @@
-#include "elna/parser.hpp"
 #include "elna/riscv.hpp"
 #include <memory>
 #include <cstring>
@@ -59,31 +58,22 @@ namespace elna
         return reinterpret_cast<std::byte *>(&this->instruction) + sizeof(this->instruction);
     }
 
-    void RiscVVisitor::visit(Node *)
+    void RiscVVisitor::visit(source::definition *definition)
     {
+        constants[definition->identifier()] = definition->body().number();
     }
 
-    void RiscVVisitor::visit(Definition *definition)
+    void RiscVVisitor::visit(source::block *block)
     {
-        ++constCount;
+        for (const auto& block_definition : block->definitions())
-        constNames = reinterpret_cast<const char **>(realloc(constNames, sizeof(const char *) * constCount));
-        constValues = reinterpret_cast<std::int32_t *>(realloc(constValues, sizeof(std::int32_t) * constCount));
-
-        constNames[constCount - 1] = definition->identifier;
-        constValues[constCount - 1] = definition->number->value;
-    }
-
-    void RiscVVisitor::visit(Block *block)
         {
-        for (std::size_t i = 0; i < block->definitionsLength; ++i)
+            block_definition->accept(this);
-        {
-            block->definitions[i]->accept(this);
         }
         this->instructionsLength += 4;
         this->instructions = reinterpret_cast<Instruction *>(
                 realloc(this->instructions, this->instructionsLength * sizeof(Instruction)));
 
-        block->statement->accept(this);
+        block->body().accept(this);
 
         // Prologue.
         const uint stackSize = static_cast<std::uint32_t>(variableCounter * 4 + 12);
@@ -137,44 +127,12 @@ namespace elna
             .i(XRegister::zero, Funct3::jalr, XRegister::ra, 0);
     }
 
-    void RiscVVisitor::visit(BangStatement *statement)
+    void RiscVVisitor::visit(source::bang_statement *statement)
     {
-        statement->expression->accept(this);
+        statement->body().accept(this);
     }
 
-    void RiscVVisitor::visit(Expression *operand)
+    void RiscVVisitor::visit(source::variable *variable)
-    {
-        if (dynamic_cast<Variable *>(operand) != nullptr)
-        {
-            return dynamic_cast<Variable *>(operand)->accept(this);
-        }
-        if (dynamic_cast<Number *>(operand) != nullptr)
-        {
-            return dynamic_cast<Number *>(operand)->accept(this);
-        }
-    }
-
-    void RiscVVisitor::visit(Variable *variable)
-    {
-        std::size_t i = 0;
-        for (; i < constCount; ++i)
-        {
-            if (std::strcmp(variable->identifier, constNames[i]) == 0)
-            {
-                break;
-            }
-        }
-        const auto freeRegister = this->registerInUse ? XRegister::a0 : XRegister::t0;
-
-        ++this->instructionsLength;
-        this->instructions = reinterpret_cast<Instruction *>(
-                realloc(this->instructions, this->instructionsLength * sizeof(Instruction)));
-        this->instructions[this->instructionsLength - 1] =
-            Instruction(BaseOpcode::opImm) // movl $x, %eax; where $x is a number.
-                .i(freeRegister, Funct3::addi, XRegister::zero, constValues[i]);
-    }
-
-    void RiscVVisitor::visit(Number *number)
     {
         const auto freeRegister = this->registerInUse ? XRegister::a0 : XRegister::t0;
 
@@ -183,15 +141,27 @@ namespace elna
                 realloc(this->instructions, this->instructionsLength * sizeof(Instruction)));
         this->instructions[this->instructionsLength - 1] =
             Instruction(BaseOpcode::opImm) // movl $x, %eax; where $x is a number.
-                .i(freeRegister, Funct3::addi, XRegister::zero, number->value);
+                .i(freeRegister, Funct3::addi, XRegister::zero, constants[variable->name()]);
     }
 
-    void RiscVVisitor::visit(BinaryExpression *expression)
+    void RiscVVisitor::visit(source::integer_literal *number)
+    {
+        const auto freeRegister = this->registerInUse ? XRegister::a0 : XRegister::t0;
+
+        ++this->instructionsLength;
+        this->instructions = reinterpret_cast<Instruction *>(
+                realloc(this->instructions, this->instructionsLength * sizeof(Instruction)));
+        this->instructions[this->instructionsLength - 1] =
+            Instruction(BaseOpcode::opImm) // movl $x, %eax; where $x is a number.
+                .i(freeRegister, Funct3::addi, XRegister::zero, number->number());
+    }
+
+    void RiscVVisitor::visit(source::binary_expression *expression)
     {
         const auto lhs_register = this->registerInUse ? XRegister::a0 : XRegister::t0;
 
         this->registerInUse = true;
-        expression->lhs->accept(this);
+        expression->lhs().accept(this);
 
         ++this->instructionsLength;
         this->instructions = reinterpret_cast<Instruction *>(
@@ -202,7 +172,7 @@ namespace elna
         auto lhs_stack_position = ++this->variableCounter;
 
         this->registerInUse = false;
-        expression->rhs->accept(this);
+        expression->rhs().accept(this);
 
         this->instructionsLength += 2;
         this->instructions = reinterpret_cast<Instruction *>(
@@ -213,24 +183,24 @@ namespace elna
                 static_cast<std::int8_t>((lhs_stack_position - 1) * 4));
 
         // Calculate the result and assign it to a variable on the stack.
-        switch (expression->_operator)
+        switch (expression->operation())
         {
-            case BinaryOperator::sum:
+            case source::binary_operator::sum:
                 this->instructions[instructionsLength - 1] = Instruction(BaseOpcode::op)
                     .r(lhs_register, Funct3::add, XRegister::a0, XRegister::t0);
                 break;
-            case BinaryOperator::subtraction:
+            case source::binary_operator::subtraction:
                 this->instructions[instructionsLength - 1] = Instruction(BaseOpcode::op)
                     .r(lhs_register, Funct3::sub, XRegister::a0, XRegister::t0, Funct7::sub);
                 break;
-            case BinaryOperator::multiplication:
+            case source::binary_operator::multiplication:
                 this->instructions[instructionsLength - 1] = Instruction(BaseOpcode::op)
                     .r(lhs_register, Funct3::mul, XRegister::a0, XRegister::t0, Funct7::muldiv);
                 break;
         }
     }
 
-    Symbol writeNext(Block *ast)
+    Symbol writeNext(source::block *ast)
     {
         auto visitor = std::make_unique<RiscVVisitor>();
         visitor->visit(ast);