
    <<FileSegment.mesa>>
        <<Copyright  1985 by Xerox Corporation.  All rights reserved.>>
        <<Satterthwaite, 29-Oct-81 12:56:05>>
        <<Rovner, May 13, 1983 2:38 pm>>
    <<Russ Atkinson (RRA) January 31, 1985 1:08:41 pm PST>>

    FileSegment: DEFINITIONS = {
        Span: TYPE = RECORD[
            base: NAT,        -- base page (0 = leader, if present)
            pages: NAT        -- interval is [base .. base+pages)
            ];

        nullSpan: Span = [0, 0];

        Pages: TYPE = RECORD[
            file: REF ANY,
            span: Span
            ];

        nullPages: Pages = [NIL, nullSpan];
        voidPages: Pages = [NIL, [1, 0]];    -- used as flag  

        }.

