From c02c88b6f09a22a318ce89137746d22efbacea4e Mon Sep 17 00:00:00 2001
From: Mark Thom <markjordanthom@gmail.com>
Date: Mon, 16 Apr 2018 22:00:30 -0600
Subject: [PATCH 1/3] add functional notation for operators.

---
 src/prolog/io.rs  | 1 +
 src/prolog/parser | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/prolog/io.rs b/src/prolog/io.rs
index 85e5330c..1b005bd3 100644
--- a/src/prolog/io.rs
+++ b/src/prolog/io.rs
@@ -679,6 +679,7 @@ pub fn compile_listing(wam: &mut Machine, src_str: &str) -> EvalSession
                         .or_insert(CodeIndex::default());
 
                     index.0.set(IndexPtr::Index(p));
+                    index.1 = module_name;
                 }
                 
                 decl_info.label_clauses(p, &mut code_dir, &mut decl_code);
diff --git a/src/prolog/parser b/src/prolog/parser
index 0e9dd3a0..1b3bcc77 160000
--- a/src/prolog/parser
+++ b/src/prolog/parser
@@ -1 +1 @@
-Subproject commit 0e9dd3a01f21c6457bd1bcb35518ccdb502c82bd
+Subproject commit 1b3bcc77f2b9d264c9753653ae87bfa3b4c11081

From 35694e76220ab3c344be4044896381561ba32dfb Mon Sep 17 00:00:00 2001
From: Mark Thom <markjordanthom@gmail.com>
Date: Mon, 16 Apr 2018 23:25:37 -0600
Subject: [PATCH 2/3] print characters correctly

---
 src/prolog/ast.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/prolog/ast.rs b/src/prolog/ast.rs
index 1128a800..bee15064 100644
--- a/src/prolog/ast.rs
+++ b/src/prolog/ast.rs
@@ -537,7 +537,7 @@ impl fmt::Display for Constant {
             &Constant::Atom(ref atom) =>
                 write!(f, "{}", atom),
             &Constant::Char(c) =>
-                write!(f, "#\\{}", c),
+                write!(f, "{}", c as u8),
             &Constant::EmptyList =>
                 write!(f, "[]"),
             &Constant::Number(ref n) =>

From 56318b09d0ec092c161ecc319d234a338680f65f Mon Sep 17 00:00:00 2001
From: Mark Thom <markjordanthom@gmail.com>
Date: Tue, 17 Apr 2018 09:26:13 -0600
Subject: [PATCH 3/3] add predicate existence errors for failed metacalls.

---
 src/prolog/machine/machine_state.rs | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/src/prolog/machine/machine_state.rs b/src/prolog/machine/machine_state.rs
index 049223f8..c76edba2 100644
--- a/src/prolog/machine/machine_state.rs
+++ b/src/prolog/machine/machine_state.rs
@@ -426,17 +426,16 @@ pub(crate) trait CallPolicy: Any {
 
                 Ok(())
             },
-            &ClauseType::CallN => {
+            &ClauseType::CallN =>
                 if let Some((name, arity)) = machine_st.setup_call_n(arity) {
                     if let Some(idx) = code_dirs.get(name.clone(), arity, &machine_st.p.clone()) {
-                        return self.context_call(machine_st, name, arity, idx, lco);
+                        self.context_call(machine_st, name, arity, idx, lco)
                     } else {
-                        machine_st.fail = true;
+                        Err(predicate_existence_error(name, arity, machine_st.heap.h))
                     }
-                }
-
-                Ok(())
-            },
+                } else {
+                    Ok(())
+                },
             &ClauseType::Compare => {
                 let a1 = machine_st[temp_v!(1)].clone();
                 let a2 = machine_st[temp_v!(2)].clone();