Implement argument passing

README.md

@@ -28,6 +28,8 @@ integer = digit { digit };
 float = integer "." integer;
 boolean = "true" | "false";
 
+literal = integer | float | boolean | "'" character "'" | """ { character } """;
+
 program = [ "type" type_definitions ";" ]
     [ constant_part ]
     { procedure_definition }
@@ -64,11 +66,7 @@ comparand = summand { ("+" | "-") summand };
 summand = factor { ("*" | "/") factor };
 factor = pointer { unary_prefix pointer };
 
-pointer = integer
-        | float
-        | boolean
-        | "'" character "'"
-        | """ { character } """
+pointer = literal
         | designator_expression { $$ = $1; }
         | "(" expression ")";