switch to machine implemented arg

2018-05-13 14:55:44 -06:00
parent 175a5db5d7
commit 81d0538a5c
6 changed files with 101 additions and 62 deletions
--- a/src/prolog/machine/machine_state.rs
+++ b/src/prolog/machine/machine_state.rs
@@ -410,6 +410,10 @@ pub(crate) trait CallPolicy: Any {
                machine_st.fail = machine_st.is_cyclic_term(addr);
                return_from_clause!(machine_st.last_call, machine_st)
            },
+            &BuiltInClauseType::Arg => {
+                machine_st.try_arg()?;
+                return_from_clause!(machine_st.last_call, machine_st)
+            },
            &BuiltInClauseType::Compare => {
                let a1 = machine_st[temp_v!(1)].clone();
                let a2 = machine_st[temp_v!(2)].clone();