Copyright Ó 1988, 1992 by Xerox Corporation. All rights reserved.

Christian Jacobi, August 26, 1988 11:12:22 am PDT

Christian Jacobi, October 6, 1988 12:50:03 pm PDT

IO USING [STREAM],

Rope USING [ROPE];

--Creates top level window with input, output and error stream for typescript-style I/O.

--header: may be header line or simply first output, depending on window system.

--windowSystem: preferred window system. Use this windowSystem if it is implemented,

-- but otherwise use the "current" window system. Usually NIL or an atom.

--echo: Whether input echos to the output stream. If no echo, streams returned are

-- extremely simple, the input stream offers no editing, comment filtering,

-- or echoing to the output stream. The client is free to layer these features

-- anyway on top using the IO or EditedStream interface.

-- Restriction: there might be "windowSystem" implementors which fail to

-- implement the non echoed input stream; Clients can test for this using

-- the returned hasEcho boolean.

--Returns in, out, err: streams; out and err might be identical; err is useful for

-- simulating unix, but is mostly ignored by more Cedarish clients.

--The streams will raise IO.EndOfStream if the window is interactively destroyed (using

-- a "windowSystem" dependent action).

--Closing a stream might or might not remove the window.

CreateProcType: TYPE = PROC [header: Rope.ROPE ¬ NIL, echo: BOOL ¬ TRUE, windowSystem: REF ¬ NIL] RETURNS [in, out, err: IO.STREAM ¬ NIL, hasEcho: BOOL ¬ FALSE];

ImplementCreate: PROC [windowSystem: REF, create: CreateProcType, setCurrent: BOOL ¬ TRUE];

SetCurrentCreate: PROC [windowSystem: REF, scope: REF ¬ NIL];