From 11198fdb31d622657e0dacb33aacdb1d4224834f Mon Sep 17 00:00:00 2001
From: Mark Thom <markjordanthom@gmail.com>
Date: Sun, 24 Mar 2019 00:26:29 -0600
Subject: [PATCH] print attribute goals alongside variable bindings as a
 single, unified goals

---
 src/prolog/lib/freeze.pl  |  2 +-
 src/prolog/machine/mod.rs | 11 +++++------
 src/prolog/write.rs       | 39 ++++++++++++++++++++++++++-------------
 3 files changed, 32 insertions(+), 20 deletions(-)

diff --git a/src/prolog/lib/freeze.pl b/src/prolog/lib/freeze.pl
index 2eb24951..d3a92eaf 100644
--- a/src/prolog/lib/freeze.pl
+++ b/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).
diff --git a/src/prolog/machine/mod.rs b/src/prolog/machine/mod.rs
index 584aad87..01e8527e 100644
--- a/src/prolog/machine/mod.rs
+++ b/src/prolog/machine/mod.rs
@@ -250,13 +250,12 @@ impl Machine {
         Ok(())
     }
     
-    pub fn remove_unbound_vars(&self, heap_locs: &mut HeapVarDict) {
-        for (var, addr) in heap_locs.clone() {
+    pub fn remove_unbound_vars(&self, orig_heap_locs: &HeapVarDict, heap_locs: &mut HeapVarDict) {
+        for (var, addr) in orig_heap_locs.iter() {
             match self.machine_st.store(self.machine_st.deref(addr.clone())) {
-                new_addr =>
-                    if addr.is_ref() && new_addr == addr {
-                        heap_locs.remove(&var);
-                    }
+                new_addr => if new_addr.is_ref() {
+                    heap_locs.remove(var);
+                }
             }
         }
     }
diff --git a/src/prolog/write.rs b/src/prolog/write.rs
index 78c59ba8..c7da956e 100644
--- a/src/prolog/write.rs
+++ b/src/prolog/write.rs
@@ -371,33 +371,46 @@ 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) => {            
+        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();
                 }
-                
+
                 let mut raw_stdout = stdout().into_raw_mode().unwrap();
 
                 if !heap_locs.is_empty() {
-                    let mut output = PrinterOutputter::new();                    
+                    let mut output = PrinterOutputter::new();
                     let bindings = wam.heap_view(&heap_locs, output).result();
-                    
+
                     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() {
-                        write!(raw_stdout, "\r\n{}\r\n", attr_goals).unwrap();
+                if !attr_goals.is_empty() {
+                    if heap_locs.is_empty() {
+                        write!(raw_stdout, "{}", attr_goals).unwrap();
+                    } else {
+                        write!(raw_stdout, ", {}", attr_goals).unwrap();
                     }
                 }
 
@@ -425,9 +438,9 @@ pub fn print(wam: &mut Machine, result: EvalSession) {
                         write!(raw_stdout, "{}\r\n", error_string(e)).unwrap();
                         raw_stdout.flush().unwrap();
                         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();
-- 
2.54.0