Check should_continue once per iteration

Author: detrumi

chalk-recursive/src/recursive.rs

@@ -143,7 +143,6 @@ impl<I: Interner> chalk_solve::Solver<I> for RecursiveSolver<I> {
         goal: &UCanonical<InEnvironment<Goal<I>>>,
         should_continue: &dyn std::ops::Fn() -> bool,
     ) -> Option<chalk_solve::Solution<I>> {
-        // TODO support should_continue in recursive solver
         self.ctx
             .solve_root_goal(goal, program, should_continue)
             .ok()

chalk-recursive/src/solve.rs

@@ -43,6 +43,10 @@ pub(super) trait SolveIteration<I: Interner>: SolveDatabase<I> {
         minimums: &mut Minimums,
         should_continue: impl std::ops::Fn() -> bool + Clone,
     ) -> Fallible<Solution<I>> {
+        if !should_continue() {
+            return Err(NoSolution);
+        }
+
         let UCanonical {
             universes,
             canonical: