add provisional module support.

src/prolog/mod.rs

@@ -4,9 +4,10 @@ extern crate ordered_float;
 pub mod allocator;
 pub mod and_stack;
 #[macro_use]
+pub mod macros;
+#[macro_use]
 pub mod ast;
 #[macro_use]
-pub mod macros;
 pub mod arithmetic;
 pub mod builtins;
 pub mod codegen;
@@ -20,6 +21,7 @@ pub mod io;
 pub mod iterators;
 pub mod machine;
 pub mod or_stack;
+#[macro_use]
 pub mod parser;
 pub mod targets;
 pub mod tabled_rc;