add atom predicate.

2018-03-10 15:26:35 -07:00
parent 2cc5367c52
commit 7500465b38
10 changed files with 248 additions and 205 deletions
--- a/src/prolog/io.rs
+++ b/src/prolog/io.rs
@@ -249,6 +249,8 @@ impl fmt::Display for BuiltInInstruction {
                write!(f, "unwind_stack"),
            &BuiltInInstruction::Unify =>
                write!(f, "unify"),
+            &BuiltInInstruction::IsAtom(r) =>
+                write!(f, "is_atom {}", r),
            &BuiltInInstruction::IsAtomic(r) =>
                write!(f, "is_atomic {}", r),
            &BuiltInInstruction::IsCompound(r) =>