Add multiple of the pointer target size

tools/main.cc

@@ -0,0 +1,41 @@
+#include <elna/source/driver.h>
+#include "parser.hh"
+#include <sstream>
+
+constexpr std::size_t pointer_size = 4;
+
+int main()
+{
+    elna::source::driver driver{ "-" };
+    std::istringstream inp(R"(
+        proc f();
+        begin
+        end;
+
+        var x: Int;
+
+        begin
+            x := 4 + 2
+        end.
+    )");
+
+    elna::source::lexer lexer(inp);
+    yy::parser parser(lexer, driver);
+    
+    if (auto result = parser())
+    {
+        for (const auto& error : driver.errors())
+        {
+            std::cerr << error->path << ':'
+                << error->line() << ':' << error->column()
+                << ": error: " << error->what()
+                << '.' << std::endl;
+        }
+        return result;
+    }
+    for (auto& definition : driver.tree->definitions())
+    {
+        std::cout << "Definition identifier: " << definition->identifier() << std::endl;
+    }
+    return 0;
+}