
    <<X11SchemeServer.mesa>>
        <<Copyright Ó 1991, 1992 by Xerox Corporation.  All rights reserved.>>
        <<Christian Jacobi, April 24, 1991 5:26 pm PDT>>
        <<Christian Jacobi, May 10, 1991 12:23 pm PDT>>
        <<>>
    DIRECTORY 
        Commander, CommanderOps, IO, Rope, Scheme, X11EvalServer;

    X11SchemeServer: CEDAR PROGRAM
        IMPORTS Commander, CommanderOps, IO, Rope, Scheme, X11EvalServer ~ 
    BEGIN

    CreateListenerCommand: Commander.CommandProc ~ {
        success: BOOL; message: Rope.ROPE;
        display: Rope.ROPE ¬ NIL;
        selection: Rope.ROPE ¬ "CedarScheme";
        userEnv: Scheme.Environment ¬ Scheme.NewEnvironmentStructure[];
        DO
            arg: Rope.ROPE ¬ CommanderOps.NextArgument[cmd];
            IF arg=NIL THEN EXIT;
            SELECT TRUE FROM
                Rope.Equal[arg, "-display", FALSE] => display ¬ CommanderOps.NextArgument[cmd];
                Rope.Equal[arg, "-selection", FALSE] => selection ¬ CommanderOps.NextArgument[cmd];
                ENDCASE => CommanderOps.Failed["unknown argument"];
            ENDLOOP;
        [success, message] ¬ X11EvalServer.Create[server: display, selection: selection, proc: CommandProc, environment: userEnv];
        IF success 
            THEN msg ¬ "ok"
            ELSE {
                msg ¬ Rope.Concat["selection ownership not established ", message];
                result ¬ $Failure
                };
        };

    CommandProc: PROC [in: Rope.ROPE, environment: REF] RETURNS [out: Rope.ROPE ¬ NIL, result: REF ¬ NIL] = {
        inStream, outStream: IO.STREAM;
        userEnv: Scheme.Environment ¬ NARROW[environment];
        inStream ¬ IO.RIS[in];
        outStream ¬ IO.ROS[];
        Scheme.ReadEvalPrintLoop[inStream, outStream, userEnv];
        out ¬ IO.RopeFromROS[outStream];
        };

    Commander.Register["X11SchemeServer", CreateListenerCommand, "create an interop scheme listener"];
    END.