From 112d398175f244d1fbf5190c1f128b55beadf71c Mon Sep 17 00:00:00 2001
From: Nicolas Luck <nicolas@lucksus.eu>
Date: Tue, 11 Jul 2023 14:24:30 +0200
Subject: [PATCH] Add Machine::run_input_once() which reads one goal from user
 input and runs it

---
 src/machine/mod.rs | 4 ++++
 src/toplevel.pl    | 3 +++
 2 files changed, 7 insertions(+)

diff --git a/src/machine/mod.rs b/src/machine/mod.rs
index f7beecd3..9a1c978a 100644
--- a/src/machine/mod.rs
+++ b/src/machine/mod.rs
@@ -307,6 +307,10 @@ impl Machine {
         self.run_module_predicate(atom!("$toplevel"), (atom!("$repl"), 1));
     }
 
+    pub fn run_input_once(&mut self) {
+        self.run_module_predicate(atom!("$toplevel"), (atom!("run_input_once"), 0));
+    }
+
     pub fn set_user_input(&mut self, input: String) {
         self.user_input = Stream::from_owned_string(input, &mut self.machine_st.arena);
     }
diff --git a/src/toplevel.pl b/src/toplevel.pl
index 8caea7ba..56b8df94 100644
--- a/src/toplevel.pl
+++ b/src/toplevel.pl
@@ -430,3 +430,6 @@ print_exception_with_check(E) :-
     % is expected to be printed instead.
     ;  print_exception(E)
     ).
+
+run_input_once :-
+    catch(read_and_match, E, print_exception(E)).
-- 
2.54.0