fix 'drain lower bound was too large', store user-level expansions to modules (#416)

src/prolog/codegen.rs

@@ -343,7 +343,9 @@ impl<'a, TermMarker: Allocator<'a>> CodeGenerator<TermMarker> {
                 &mut ControlInstruction::CallClause(_, _, _, ref mut last_call, _) => {
                     *last_call = true
                 }
-                &mut ControlInstruction::JmpBy(_, _, _, ref mut last_call) => *last_call = true,
+                &mut ControlInstruction::JmpBy(_, _, _, ref mut last_call) => {
+                    *last_call = true
+                }
                 &mut ControlInstruction::Proceed => {}
                 _ => dealloc_index += 1,
             },

src/prolog/lib/builtins.pl

@@ -569,7 +569,8 @@ setof(Template, Goal, Solution) :-
 
 clause(H, B) :-
     (  var(H) -> throw(error(instantiation_error, clause/2))
-    ;  functor(H, Name, Arity) -> (  Name == '.' -> throw(error(type_error(callable, H), clause/2))
+    ;  functor(H, Name, Arity) ->
+       (  Name == '.' -> throw(error(type_error(callable, H), clause/2))
 	   ;  Name == (:), Arity =:= 2 ->
 		  arg(1, H, Module),
 		  arg(2, H, F),

src/prolog/machine/compile.rs

@@ -188,6 +188,8 @@ fn set_first_index(code: &mut Code) {
                 if *offset == 0 =>
             {
                 *offset = code_len - idx;
+                debug_assert!(*offset > 0);
+
                 break;
             }
             _ => {}
@@ -880,7 +882,6 @@ impl ListingCompiler {
 
         let (mut len, mut queue_len) = ((preds.0).0.len(), preds.1.len());
 
-        if self.module.is_some() && hook.has_module_scope() {
         let module_preds = self
             .user_term_dir
             .entry(key.clone())
@@ -896,20 +897,10 @@ impl ListingCompiler {
 
         (preds.0).0.extend((module_preds.0).0.iter().cloned());
         preds.1.extend(module_preds.1.iter().cloned());
-        } else {
-            let module_preds = self
-                .user_term_dir
-                .entry(key.clone())
-                .or_insert((Predicate::new(), VecDeque::from(vec![])));
 
+        if !(self.module.is_some() && hook.has_module_scope()) {
             len += 1;
             queue_len += queue_len;
-
-            (preds.0).0.push(clause);
-            preds.1.extend(queue.into_iter());
-
-            (preds.0).0.extend((module_preds.0).0.iter().cloned());
-            preds.1.extend(module_preds.1.iter().cloned());
         }
 
         (len, queue_len)

src/prolog/machine/dynamic_database.rs

@@ -307,6 +307,12 @@ impl Machine {
                     }
                 }
             }
+            Addr::Usize(n) => {
+                n
+            }
+            Addr::Fixnum(n) => {
+                usize::try_from(n).unwrap()
+            }
             _ => {
                 unreachable!()
             }

src/prolog/machine/modules.rs

@@ -48,6 +48,7 @@ impl Module {
             (te.0)
                 .0
                 .extend((self.user_term_expansions.0).0.iter().cloned());
+
             te.1.extend(self.user_term_expansions.1.iter().cloned());
         }
 
@@ -60,6 +61,7 @@ impl Module {
             (ge.0)
                 .0
                 .extend((self.user_goal_expansions.0).0.iter().cloned());
+
             ge.1.extend(self.user_goal_expansions.1.iter().cloned());
         }
 

src/prolog/machine/toplevel.rs

@@ -872,6 +872,7 @@ impl RelationWorker {
                     let term = Term::Clause(Cell::default(), clause_name!(";"), terms, None);
                     let (stub, clauses) = self.fabricate_disjunct(term);
 
+                    debug_assert!(clauses.len() > 0);
                     self.queue.push_back(clauses);
                     Ok(QueryTerm::Jump(stub))
                 }