<<>>
    <<XlAccessImplPrincOps.mesa>>
        <<Copyright Ó 1988, 1989, 1990, 1991 by Xerox Corporation.  All rights reserved.>>
        <<Christian Jacobi, May 11, 1988>>
        <<Christian Jacobi, February 22, 1990>>
        <<Christian Jacobi, October 9, 1992 0:40 am PDT>>
        <<>>
    DIRECTORY 
        Arpa, ArpaName, Atom, Identification, IO, XlAccess, Rope, ThisMachine, UserProfile;

    XlAccessAndNameTranslationlPrincOps: CEDAR PROGRAM
        IMPORTS ArpaName, Atom, IO, Rope, ThisMachine, UserProfile
        EXPORTS XlAccess, Identification
    ~ BEGIN 

    Self: PUBLIC PROC [a: ATOM ¬ NIL] RETURNS [Rope.ROPE] = {
        SELECT a FROM
            NIL => RETURN [ThisMachine.Name[]];
            ENDCASE => RETURN [ThisMachine.Name[]];
        };
        <<>>
    ServerNameFromProperties: PROC [for: ATOM] RETURNS [name: Rope.ROPE ¬ NIL] = {
        IF for=NIL THEN for ¬ $X11;
        WITH Atom.GetProp[atom: for, $DISPLAY] SELECT FROM
            r: Rope.ROPE => name ¬ r;
            ENDCASE => {};
        };

    DefaultServer: PUBLIC PROC [for: ATOM ¬ NIL] RETURNS [serverName: Rope.ROPE] = {
        serverKey: Rope.ROPE; 
        IF for#$UserProfile THEN {
            serverName ¬ ServerNameFromProperties[for];
            IF Rope.IsEmpty[serverName] AND for#NIL THEN 
                serverName ¬ ServerNameFromProperties[NIL]
            };
        IF Rope.IsEmpty[serverName] THEN {
            IF for=NIL 
                THEN serverKey ¬ "X11.ServerName" 
                ELSE serverKey ¬ Rope.Concat["X11.ServerName.", Atom.GetPName[for]]; 
            serverName ¬ UserProfile.Token[serverKey];
            IF Rope.IsEmpty[serverName] AND for#NIL THEN 
                serverName ¬ UserProfile.Token["X11.ServerName"];
            };
        };

    AddressFromNameFailed: PUBLIC ERROR [msg: Rope.ROPE] = CODE;

    StatusToRope: PROC [status: ArpaName.ReplyStatus] RETURNS [msg: Rope.ROPE] = {
        msg ¬ SELECT status FROM
        ok => "ArpaName: ok",
        bogus => "ArpaName: Invalid name/address",
        other => "ArpaName: Entry is of other type. Try a different type of query",
        down => "ArpaName: Servers for address are not responding properly. Try again later",
            ENDCASE => "ArpaName: other"
        };

    NameToAddress: PUBLIC PROC [name: Rope.ROPE] RETURNS [address: Rope.ROPE] = {
        a: Arpa.Address; status: ArpaName.ReplyStatus; 
        [addr~a, status~status] ¬ ArpaName.NameToAddress[name];
        IF status#ok THEN AddressFromNameFailed[StatusToRope[status]];
        IF a=Arpa.nullAddress THEN AddressFromNameFailed["null address"];
        address ¬ IO.PutFR["%g.%g.%g.%g", IO.int[a.a], IO.int[a.b], IO.int[a.c], IO.int[a.d]]
        };

    END.