m3tk/src/files/Common/M3PathElem.i3

 Copyright (C) 1993, Digital Equipment Corporation           
 All rights reserved.                                        
 See the file COPYRIGHT for a full description.              


 M3PathElem provides the abstraction of a search path element,
defined as a file system directory. 


INTERFACE M3PathElem;

CONST
  Brand = "M3PathElem";

TYPE T <: Public;
  Public = OBJECT
  METHODS
    text(): TEXT;
    unexpanded(): TEXT;
    readOnly(): BOOLEAN;
    setReadOnly(ro: BOOLEAN := TRUE);
  END;

CONST
  CurrentDir = "";

 An M3PathElem.T is a unique representative for a set of {\it
equal} directories, where equality is a file system specific notion.
For example two textually different names may denote the same
directory by the mechanism of symbolic links.  The text method
returns the directory name after any environment variables have been
expanded.  unexpanded returns the unexpanded form. readOnly
implies that the directory has been designated as read-only.  The
read-only status may be changed via the setReadOnly call.


CurrentDir can be used as an operating system independent denotation
for the current working directory. If it is passed to FromText it is
as if Process.GetWorkingDirectory() had been passed instead. 


PROCEDURE Equal(e1, e2: T): BOOLEAN;

 Returns e1 = e2. 

PROCEDURE FromText(expanded, unexpanded: TEXT;
                   readOnly := FALSE): T;

 Return an T object for expanded, such that t.text() will return
expanded,  t.unexpanded() will return unexpanded and t.readOnly() 
will return readOnly. 

END M3PathElem.