print attribute goals alongside variable bindings as a single, unified goals

src/prolog/lib/freeze.pl

@@ -22,7 +22,7 @@ freeze(X, Goal) :-
 
 gather_freeze_goals(Attrs, _, _) :-
     var(Attrs), !.
-gather_freeze_goals([frozen(X) | _], Var, [frozen(Var, X) | _]) :-
+gather_freeze_goals([frozen(X) | _], Var, [freeze(Var, X) | _]) :-
     !.
 gather_freeze_goals([_ | Attrs], Var, Goals) :-
     gather_freeze_goals(Attrs, Var, Goals).

src/prolog/machine/mod.rs

@@ -250,13 +250,12 @@ impl Machine {
         Ok(())
     }
     
-    pub fn remove_unbound_vars(&self, heap_locs: &mut HeapVarDict) {
+    pub fn remove_unbound_vars(&self, orig_heap_locs: &HeapVarDict, heap_locs: &mut HeapVarDict) {
-        for (var, addr) in heap_locs.clone() {
+        for (var, addr) in orig_heap_locs.iter() {
             match self.machine_st.store(self.machine_st.deref(addr.clone())) {
-                new_addr =>
+                new_addr => if new_addr.is_ref() {
-                    if addr.is_ref() && new_addr == addr {
+                    heap_locs.remove(var);
-                        heap_locs.remove(&var);
+                }
-                    }
             }
         }
     }

src/prolog/write.rs

@@ -372,15 +372,24 @@ fn next_step(mut stdout: RawTerminal<std::io::Stdout>) -> ContinueResult
 pub fn print(wam: &mut Machine, result: EvalSession) {
     match result {
         EvalSession::InitialQuerySuccess(alloc_locs, mut heap_locs) => {
+            let orig_heap_locs = heap_locs.clone();
+
             loop {
-                wam.remove_unbound_vars(&mut heap_locs);
+                wam.remove_unbound_vars(&orig_heap_locs, &mut heap_locs);
 
                 if wam.or_stack_is_empty() {
                     if heap_locs.is_empty() {
-                        println!("true.");
+                        let attr_goals = wam.attribute_goals(&orig_heap_locs);
+
+                        if !attr_goals.is_empty() {
+                            println!("{}.", attr_goals);
+                        } else {
+                            println!("true.");
+                        }
+
                         return;
                     }
-                } else if heap_locs.is_empty() {
+                } else if heap_locs.is_empty() && orig_heap_locs.is_empty() {
                     print!("true");
                     stdout().flush().unwrap();
                 }
@@ -393,11 +402,15 @@ pub fn print(wam: &mut Machine, result: EvalSession) {
 
                     write!(raw_stdout, "{}", bindings).unwrap();
                     raw_stdout.flush().unwrap();
+                }
 
-                    let attr_goals = wam.attribute_goals(&heap_locs);
+                let attr_goals = wam.attribute_goals(&orig_heap_locs);
 
-                    if !attr_goals.is_empty() {
+                if !attr_goals.is_empty() {
-                        write!(raw_stdout, "\r\n{}\r\n", attr_goals).unwrap();
+                    if heap_locs.is_empty() {
+                        write!(raw_stdout, "{}", attr_goals).unwrap();
+                    } else {
+                        write!(raw_stdout, ", {}", attr_goals).unwrap();
                     }
                 }
 
@@ -427,7 +440,7 @@ pub fn print(wam: &mut Machine, result: EvalSession) {
                         return;
                     }
                 } else {
-                    if heap_locs.is_empty() {
+                    if heap_locs.is_empty() && attr_goals.is_empty() {
                         write!(raw_stdout, "true.\r\n").unwrap();
                     } else {
                         write!(raw_stdout, ".\r\n").unwrap();