TiogaAccessExample.mesa
Copyright Ó 1984, 1991, Xerox Corporation. All rights reserved.
Michael Plass, March 25, 1985 5:10:28 pm PST
DIRECTORY
MessageWindow USING [Append, Blink],
Rope USING [ROPE],
RuntimeError USING [UNCAUGHT],
TiogaAccess USING [CopyNode, Create, DoneWith, EndOf, FromFile, FromSelection, Get, PeekRope, Put, Reader, TiogaChar, WriteFile, Writer, WriteSelection],
TiogaOps USING [CallWithLocks, Ref];
TiogaAccessExample: CEDAR PROGRAM
IMPORTS MessageWindow, RuntimeError, TiogaAccess, TiogaOps
~ BEGIN
ROPE: TYPE ~ Rope.ROPE;
SaveSelection: PROC [fileName: ROPE] ~ {
out: TiogaAccess.Writer ¬ TiogaAccess.Create[];
in: TiogaAccess.Reader ¬ TiogaAccess.FromSelection[];
UNTIL TiogaAccess.EndOf[in] DO
DO
tiogaChar: TiogaAccess.TiogaChar ¬ TiogaAccess.Get[in];
TiogaAccess.Put[out, tiogaChar];
IF tiogaChar.endOfNode THEN EXIT;
ENDLOOP;
ENDLOOP;
TiogaAccess.DoneWith[in];
TiogaAccess.WriteFile[out, fileName];
};
GetSelection: PROC ~ {
out: TiogaAccess.Writer ¬ TiogaAccess.Create[];
selection: TiogaAccess.Reader ¬ TiogaAccess.FromSelection[];
fileName: ROPE ¬ TiogaAccess.PeekRope[selection];
in: TiogaAccess.Reader ¬ TiogaAccess.FromFile[fileName];
Could catch FS.Error here for bad name or missing file.
TiogaAccess.DoneWith[selection];
IF NOT TiogaAccess.EndOf[in] THEN [] ¬ TiogaAccess.Get[in];
Discard root; failure to do this will cause the WriteSelection to fail.
UNTIL TiogaAccess.EndOf[in] DO
[] ¬ TiogaAccess.CopyNode[out, in]
ENDLOOP;
TiogaAccess.DoneWith[in];
TiogaAccess.WriteSelection[out];
};
ReverseSelection: PROC ~ {
buffer: LIST OF TiogaAccess.TiogaChar;
out: TiogaAccess.Writer ¬ TiogaAccess.Create[];
in: TiogaAccess.Reader ¬ TiogaAccess.FromSelection[];
UNTIL TiogaAccess.EndOf[in] DO
tiogaChar: TiogaAccess.TiogaChar;
DO
tiogaChar ¬ TiogaAccess.Get[in];
IF tiogaChar.endOfNode THEN EXIT;
buffer ¬ CONS[tiogaChar, buffer];
ENDLOOP;
UNTIL buffer = NIL DO
t: LIST OF TiogaAccess.TiogaChar ¬ buffer;
buffer ¬ t.rest;
t.rest ¬ NIL;
TiogaAccess.Put[out, t.first];
ENDLOOP;
TiogaAccess.Put[out, tiogaChar];
ENDLOOP;
TiogaAccess.DoneWith[in];
TiogaAccess.WriteSelection[out];
};
LockedReverseSelection: PROC ~ {
action: PROC [ref: TiogaOps.Ref] ~ {ReverseSelection[]};
TiogaOps.CallWithLocks[action ! RuntimeError.UNCAUGHT => {
MessageWindow.Append["Unknown error in ReverseSelection", TRUE];
MessageWindow.Blink[];
CONTINUE
}];
};
END.
CreateButton S ¬ TiogaAccessExample.SaveSelection["Save"]
CreateButton G ¬ TiogaAccessExample.GetSelection[]
CreateButton R ¬ TiogaAccessExample.ReverseSelection[]
CreateButton L ¬ TiogaAccessExample.LockedReverseSelection[]
CreateButton P ¬ TiogaAccess.GetPosition[TiogaAccess.FromSelection[]]
CreateButton s ¬ &s ¬ TiogaAccess.FromSelection[]
CreateButton t ¬ TiogaAccess.WriteSelection[&w]
¬ &w ¬ TiogaAccess.Create[]
¬ TiogaAccess.Put[&w, [charSet: 0, char: 'n, looks: ALL[FALSE], format: $default, comment: FALSE, endOfNode: FALSE, deltaLevel: 0, propList: NIL]]
¬ TiogaAccess.Put[&w, [charSet: 0, char: '\n, looks: ALL[FALSE], format: $default, comment: FALSE, endOfNode: TRUE, deltaLevel: 0, propList: NIL]]
¬ &w
¬ TiogaAccess.WriteFile[&w, "Save"]