[Indigo]<PostCedar5.2>CedarExamples>ListSortRef.mesa!1

-- File: ListSortRef.mesa

-- Last edited By Mitchell on December 20, 1982 3:27 pm

-- Last edited By Bob Hagmann on May 8, 1984 9:40:29 am PDT

DIRECTORY

Basics USING [Comparison];

ListSortRef: CEDAR DEFINITIONS = --(note 2.1)

BEGIN

Comparison: TYPE = Basics.Comparison;

CompareProc: TYPE = PROC[r1, r2: REF ANY] RETURNS [Comparison];
-- Returns less if r1^ < r2^, equal if r1^ = r2^, greater if r1^ > r2^.

CompareError: ERROR[reason: Reason];

Reason: TYPE = {typeMismatch, invalidType}; -- errors from a CompareProc

Sort: PROC[list: LIST OF REF ANY, compareProc: CompareProc] --(note 2.2)

RETURNS[LIST OF REF ANY];

-- Destructive sort; copy list first if nondestructive sort is needed.

-- Returns a list containing the same REFs as list, arranged in ascending order

--according to compareProc. Order of equal items is not preserved.

Compare: CompareProc;

-- ! SafeStorage.NarrowRefFault

-- (if both parameters do not NARROW to one of ROPE or REF INT.)

-- Compares ROPE : ROPE (case significant) and REF INT : REF INT

END.--ListSortRef

CHANGE LOG

Created by MBrown on 21-Apr-81 13:55:09

Changed by MBrown on 10-Dec-81 9:50:15
-- Change comment in Compare (now compares ROPE instead of REF TEXT.)

Changed by MBrown on July 5, 1982 4:59 pm
-- CEDAR definitions, eliminate type Item.

Edited on December 16, 1982 2:40 pm, by Mitchell

changed to use Environment.Comparison instead of internal type.

Edited on December 20, 1982 3:24 pm, by Mitchell

added CompareError and Reason to make errors generatee by a CompareProc more germane to it instead of the facilities it calls.

Edited on May 8, 1984 9:40:34 am PDT, by Bob Hagmann

Modified for Cedar 5 Environment -> Basics