tiny.acp.Observer

1/// The caller keeps the lasting record of the conversation and may answer permission requests2/// itself, so the client calls out to it before it acts on each message. The structure provides a3/// context pointer and three optional callbacks. The client calls them from inside `start` and the4/// prompt calls, in the order the messages arrive. Each update goes to `updateFn` before its text5/// joins the reply and before the client reads the next line. For a permission request,6/// `permissionFn` may answer first, and `permissionCommitFn` then receives the decision before the7/// client sends the answer to the agent. An error from `updateFn` or `permissionCommitFn` fails the8/// client call that read the message. When `updateFn` or `permissionCommitFn` is null, the first9/// message that needs it fails the call with `error.MissingDurableObserver`. The package README10/// asks the observer to commit each exact update line before it returns.11pub const Observer = struct {12    /// The caller's context, passed as the first argument to every callback.13    ptr: *anyopaque,14    /// A callback called once per update, in arrival order, with the update's numbers, its exact15    /// line and the fields read from it. The client frees the update and every string in it when16    /// the call returns, so the callback copies what it keeps. Null, the default, fails the call17    /// with `error.MissingDurableObserver` at the first update.18    updateFn: ?*const fn (*anyopaque, protocol.Update) anyerror!void = null,19    /// A callback asked first when the agent requests permission: a returned reply is used, and20    /// null leaves the decision to the permission policy. The callback sees the request with21    /// outcome `pending`, empty option fields and an empty line. Null, the default, leaves every22    /// decision to the permission policy.23    permissionFn: ?*const fn (*anyopaque, protocol.PermissionRequest) ?PermissionReply = null,24    /// A callback called with the full request, the decision and the exact line, before the client25    /// sends the answer to the agent. An error stops the answer from being sent and fails the call.26    /// The client frees the request when the call returns, so the callback copies what it keeps.27    /// Null, the default, fails the call with `error.MissingDurableObserver` at the first28    /// permission request.29    permissionCommitFn: ?*const fn (*anyopaque, protocol.PermissionRequest) anyerror!void = null,3031    fn update(self: Observer, value: protocol.Update) !void {32        const callback = self.updateFn orelse return error.MissingDurableObserver;33        try callback(self.ptr, value);34    }3536    fn permission(self: Observer, request: protocol.PermissionRequest) ?PermissionReply {37        const callback = self.permissionFn orelse return null;38        return callback(self.ptr, request);39    }4041    fn commitPermission(self: Observer, request: protocol.PermissionRequest) !void {42        const callback = self.permissionCommitFn orelse43            return error.MissingDurableObserver;44        try callback(self.ptr, request);45    }46};

1pub const Observer = client.Observer;