tail-cps

Author: Kivooeo

tests/ui/recursion/recursion-tail-cps.rs

@@ -1,17 +1,26 @@
-//@ run-pass
+//! This test verifies that mutually recursive functions implemented using CPS
+//! are correctly handled by the compiler. Specifically, it checks that such recursive calls
+//! execute without stack overflow, implying proper tail call optimization in a CPS context.
 
-fn checktrue(rs: bool) -> bool { assert!(rs); return true; }
+//@ run-pass
 
-pub fn main() { let k = checktrue; evenk(42, k); oddk(45, k); }
+fn f(x: isize, cont: fn(isize)) {
+    if x == 0 {
+        cont(0);
+    } else {
+        g(x - 1, |y| cont(y + 1));
+    }
+}
 
-fn evenk(n: isize, k: fn(bool) -> bool) -> bool {
-    println!("evenk");
-    println!("{}", n);
-    if n == 0 { return k(true); } else { return oddk(n - 1, k); }
+fn g(x: isize, cont: fn(isize)) {
+    if x == 0 {
+        cont(0);
+    } else {
+        f(x - 1, |y| cont(y + 1));
+    }
 }
 
-fn oddk(n: isize, k: fn(bool) -> bool) -> bool {
-    println!("oddk");
-    println!("{}", n);
-    if n == 0 { return k(false); } else { return evenk(n - 1, k); }
+pub fn main() {
+    f(100000, |_x| {}); // Test deep recursion
+    g(100000, |_x| {}); // Test deep recursion
 }