Implement program entry point

3 files changed, 23 insertions, 12 deletions

diff --git a/include/elna/boot/ast.h b/include/elna/boot/ast.h
index f959936..c485dc7 100644
--- a/include/elna/boot/ast.h
+++ b/include/elna/boot/ast.h
@@ -579,7 +579,7 @@ namespace elna::boot
     struct procedure_body
     {
         const std::vector<variable_declaration *> variables;
-        const std::vector<statement *> entry_point;
+        const std::vector<statement *> statements;
         expression *const return_expression{ nullptr };
 
         procedure_body(std::vector<variable_declaration *>&& variables,
@@ -593,6 +593,8 @@ namespace elna::boot
         virtual ~procedure_body();
     };
 
+    void traverse_body(parser_visitor *visitor, const procedure_body& body);
+
     /**
      * Procedure definition.
      */
@@ -940,21 +942,28 @@ namespace elna::boot
     /**
      * Stores module-level definitions.
      */
-    class unit : public node, public procedure_body
+    class unit : public node
     {
     public:
         const std::vector<import_declaration *> imports;
         const std::vector<type_declaration *> types;
         const std::vector<procedure_declaration *> procedures;
+        const std::vector<variable_declaration *> variables;
+        const std::optional<procedure_body> entry_point;
+        const std::vector<identifier> parameters;
 
-        unit(const source_position position);
+        unit(const source_position position,
+                std::vector<import_declaration *>&& imports,
+                std::vector<type_declaration *>&& types,
+                std::vector<variable_declaration *>&& variables,
+                std::vector<procedure_declaration *>&& procedures);
         unit(const source_position position,
                 std::vector<import_declaration *>&& imports,
                 std::vector<type_declaration *>&& types,
                 std::vector<variable_declaration *>&& variables,
                 std::vector<procedure_declaration *>&& procedures,
-                std::vector<statement *>&& entry_point);
-        bool has_body() const;
+                std::optional<procedure_body>&& body);
+
         void accept(parser_visitor *visitor) override;
 
         ~unit() override;
diff --git a/include/elna/boot/name_analysis.h b/include/elna/boot/name_analysis.h
index 8e945b2..cf35ab6 100644
--- a/include/elna/boot/name_analysis.h
+++ b/include/elna/boot/name_analysis.h
@@ -35,7 +35,7 @@ namespace elna::boot
      * Error declaring or using a symbol (undeclared, redefinition,
      * local export).
      */
-    class declaration_error final : public diagnostic
+    class symbol_declaration_error final : public diagnostic
     {
     public:
         enum class kind
@@ -56,7 +56,7 @@ namespace elna::boot
         };
         using payload_type = std::variant<redefinition, kind>;
 
-        declaration_error(const source_position position, const std::string& name, payload_type payload);
+        symbol_declaration_error(const source_position position, const std::string& name, payload_type payload);
 
         std::string what() const override;
         std::optional<diagnostic_note> note() const override;
@@ -80,15 +80,16 @@ namespace elna::boot
     };
 
     /**
-     * \c const qualifier used incorrectly — wrong position or duplicate.
+     * Invalid declaration format.
      */
-    class const_qualifier_error final : public diagnostic
+    class declaration_format_error final : public diagnostic
     {
     public:
         enum class kind
         {
             array_position,
-            duplicate
+            duplicate,
+            module_entry
         };
         struct not_initialized
         {
@@ -96,7 +97,7 @@ namespace elna::boot
         };
         using payload_type = std::variant<not_initialized, kind>;
 
-        const_qualifier_error(const source_position position, payload_type payload);
+        declaration_format_error(const source_position position, payload_type payload);
         std::optional<diagnostic_note> note() const override;
 
         std::string what() const override;
@@ -173,6 +174,8 @@ namespace elna::boot
         resolving_visitor(symbol_bag& bag, const target_info& target,
                 const std::filesystem::path& module_path);
 
+        procedure_type::return_t build_return_type(
+                const procedure_type_expression::return_t& return_type);
         std::pair<procedure_type, std::vector<std::string>> build_procedure(
                 procedure_type_expression& expression);
         ordered_map<type> build_composite_type(const std::vector<field_declaration>& fields,
diff --git a/include/elna/boot/type_check.h b/include/elna/boot/type_check.h
index fea7e49..345ef9d 100644
--- a/include/elna/boot/type_check.h
+++ b/include/elna/boot/type_check.h
@@ -219,7 +219,6 @@ namespace elna::boot
         explicit type_analysis_visitor(symbol_bag bag, const target_info& target);
 
         void visit(procedure_declaration *declaration) override;
-        void visit(unit *unit) override;
         void visit(assign_statement *statement) override;
         void visit(variable_declaration *declaration) override;
         void visit(type_declaration *declaration) override;