print characters correctly

diff --git a/src/prolog/ast.rs b/src/prolog/ast.rs
index 1128a80072e024c54bb42dee18c79e78e14d9e27..bee150641f1ccf9e93249f79a5e10ba8340a08a0 100644 (file)
--- 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) =>