Some API changes

* lanes.timers() can return nil, cancel_error if interrupted
* linda:receive() always return a k,v, where k is nil when v is "timeout" or cancel_error
* lanes.sleep returns nil, "timeout" during normal operations

1 files changed, 16 insertions, 3 deletions

diff --git a/src/linda.cpp b/src/linda.cpp
index 4ab89ab..2a31799 100644
--- a/src/linda.cpp
+++ b/src/linda.cpp
@@ -553,17 +553,30 @@ LUAG_FUNC(linda_receive)
         }
 
         switch (_cancel) {
+        case CancelRequest::None:
+            {
+                int const _nbPushed{ _pushed.value() };
+                if (_nbPushed == 0) {
+                    // not enough data in the linda slot to fulfill the request, return nil, "timeout"
+                    lua_pushnil(L_);
+                    std::ignore = lua_pushstringview(L_, "timeout");
+                    return 2;
+                }
+                return _nbPushed;
+            }
+
         case CancelRequest::Soft:
-            // if user wants to soft-cancel, the call returns kCancelError
+            // if user wants to soft-cancel, the call returns nil, kCancelError
+            lua_pushnil(L_);
             kCancelError.pushKey(L_);
-            return 1;
+            return 2;
 
         case CancelRequest::Hard:
             // raise an error interrupting execution only in case of hard cancel
             raise_cancel_error(L_); // raises an error and doesn't return
 
         default:
-            return _pushed.value();
+            raise_luaL_error(L_, "internal error: unknown cancel request");
         }
     };
     return Linda::ProtectedCall(L_, _receive);