// A closure literal inside a `defer` / `onfail` body is its OWN function // boundary (ERR step E1.7). Two boundary effects, both pinned here: // // (a) `checkCleanupNode` sees a bare lambda STATEMENT as a `.lambda` node and // STOPS — it does not descend into the lambda body. So the bare failable // inside the lambda is the lambda's concern, not a cleanup violation // (were the `.lambda` arm to recurse, this bare `failing()` would reject // like the ones in 1052). // // (b) value-slot liveness (E1.8) is analysed per-boundary: `flowExpr` recurses // into the lambda via `analyzeFnBody`, so a value slot read inside the // lambda must prove its own error absent — `v` here is live under its // `if !err` guard. (The rejecting counterpart is 1053.) // // Also: `try` is legal inside the lambda (it propagates through the lambda's own // `!E` channel) even though it is parser-banned in the cleanup body directly. // // Locks the closure-boundary arms of the error-flow pass before A5.2 extracts it // into its own module. Constructible since issue 0073 (closure literal in a // `defer` body no longer segfaults lowering — see 0310). #import "modules/std.sx"; E :: error { Bad } failing :: () -> !E { raise error.Bad; } recover :: () -> (s32, !E) { return 21; } work :: () { defer { // (a) bare lambda statement — checkCleanupNode stops at the `.lambda`. () -> !E { failing(); }; // (b) called closure — its body is analysed as its own boundary. emit := () -> !E { v, err := recover(); if !err { print("defer closure: v={}\n", v); } // E1.8: live under guard try failing(); }; emit() catch (e) print("defer closure: raised\n"); } print("body\n"); } main :: () -> s32 { work(); return 0; }