Initial commit

source/parser.yy

@@ -0,0 +1,141 @@
+%require "3.2"
+%language "c++"
+
+%code requires {
+    #include <cstdint>
+    #include <iostream>
+    #include "elna/source/ast.hpp"
+
+
+    #if ! defined(yyFlexLexerOnce)
+        #include <FlexLexer.h>
+    #endif
+
+    namespace elna::syntax
+    {
+    class FooLexer;
+    }
+}
+
+%code provides {
+    namespace elna::syntax
+    {
+
+    class FooLexer : public yyFlexLexer
+    {
+    public:
+        yy::location location;
+
+        FooLexer(std::istream& arg_yyin)
+            : yyFlexLexer(&arg_yyin)
+        {
+        }
+
+        yy::parser::symbol_type lex();
+    };
+
+    }
+}
+
+%define api.token.raw
+%define api.token.constructor
+%define api.value.type variant
+%define parse.assert
+
+%parse-param {elna::syntax::FooLexer& lexer}
+%parse-param {std::unique_ptr<elna::source::program>& program}
+%locations
+
+%header
+
+%code {
+    #define yylex lexer.lex
+}
+%start program;
+
+%token <std::string> IDENTIFIER "identifier"
+%token <std::int32_t> NUMBER "number"
+%token <bool> BOOLEAN
+%token IF THEN WHILE DO
+%token CONST VAR PROCEDURE
+%token BEGIN_BLOCK END_BLOCK
+%token TRUE FALSE
+%token LEFT_PAREN RIGHT_PAREN SEMICOLON DOT COMMA
+%token GREATER_EQUAL LESS_EQUAL LESS_THAN GREATER_THAN NOT_EQUAL EQUALS
+%token PLUS MINUS MULTIPLICATION DIVISION
+%token ASSIGNMENT COLON HAT AT
+
+%type <std::unique_ptr<elna::source::integer_literal>> integer_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::type_expression>> type_expression;
+%%
+program: constant_definition_part
+        {
+            elna::source::position position;
+            std::vector<std::unique_ptr<elna::source::declaration>> declarations;
+            std::vector<std::unique_ptr<elna::source::definition>> definitions($1.size());
+            std::vector<std::unique_ptr<elna::source::definition>>::iterator definition = definitions.begin();
+
+            for (auto& constant : $1)
+            {
+                *definition++ = std::move(constant);
+            }
+            program = std::make_unique<elna::source::program>(position,
+                 std::move(definitions), std::move(declarations),
+                 std::make_unique<elna::source::compound_statement>(position));
+        }
+integer_literal: NUMBER
+        {
+            elna::source::position position{
+                static_cast<std::size_t>(@1.begin.line),
+                static_cast<std::size_t>(@1.begin.column)
+            };
+            $$ = std::make_unique<elna::source::integer_literal>(position, $1); 
+        };
+type_expression:
+        HAT IDENTIFIER
+            {
+                elna::source::position position{
+                    static_cast<std::size_t>(@1.begin.line),
+                    static_cast<std::size_t>(@1.begin.column)
+                };
+                $$ = std::make_unique<elna::source::type_expression>(position, $2, true);
+            }
+        | IDENTIFIER
+            {
+                elna::source::position position{
+                    static_cast<std::size_t>(@1.begin.line),
+                    static_cast<std::size_t>(@1.begin.column)
+                };
+                $$ = std::make_unique<elna::source::type_expression>(position, $1, false);
+            }
+variable_declaration: IDENTIFIER COLON type_expression
+variable_declarations:
+        variable_declaration COMMA variable_declarations
+        | variable_declaration
+constant_definition: IDENTIFIER EQUALS integer_literal
+        {
+            elna::source::position position{
+                static_cast<std::size_t>(@1.begin.line),
+                static_cast<std::size_t>(@1.begin.column)
+            };
+            $$ = std::make_unique<elna::source::constant_definition>(position,
+                $1, std::move($3)); 
+        };
+constant_definitions:
+    constant_definition COMMA constant_definitions
+        {
+            std::swap($$, $3);
+            $$.emplace($$.cbegin(), std::move($1));
+        }
+    | constant_definition { $$.emplace_back(std::move($1)); }
+constant_definition_part:
+    /* no constant definitions */ {}
+    | CONST constant_definitions SEMICOLON { std::swap($$, $2); };
+%%
+
+void yy::parser::error(const location_type& loc, const std::string &message)
+{
+    std::cerr << "Error: " << message << std::endl;
+}