-- NutOps.mesa-- useful database utilities-- Implemented by: NutOpsImpl-- Created by: Donahue on: January 20, 1983 3:48 pm-- last edited by: Donahue, July 12, 1983 9:21 am-- Last Edited by: Willie-sue, February 22, 1983 3:44 pm-- Last Edited by: Cattell, July 22, 1983 2:59 pmDIRECTORY   DB,   ViewerClasses USING[ Viewer ],   Rope USING [ROPE];NutOps: CEDAR DEFINITIONS =BEGINOPEN DB, Rope;-- **********************************************-- Handy DB routines, implemented by NutOpsImpl.mesa-- ********************************************** IsSystemDomain:PROC[d: Domain] RETURNS[BOOLEAN];IsSystemRelation: PROC[r: Relation] RETURNS[BOOLEAN];AttributesOf: PROC[r: Relation] RETURNS[AttributeList];  -- Returns list of r's attributesFirstAttributeOf: PROC[r: Relation] RETURNS[Attribute];  -- returns AttributesOf[r].first  EntityValued: PROC [a: Attribute] RETURNS[BOOL];  -- returns TRUE iff the value stored in attribute a should be an entityGetUniquenessString: PROC[a: Attribute] RETURNS[ROPE];  -- returns the uniqueness of a: Key, OptionalKey, etc., as a printable stringRSetSize: PROC[rs: RelshipSet] RETURNS[INT];  -- returns the length of rs, and does a ReleaseRelshipSetGetTuples: PROC[e: Entity, a: Attribute] RETURNS [tl: LIST OF Relship];  -- returns all the tuples that reference e via attribute aGetRelation: PROC[a: Attribute] RETURNS[r: Relation];  -- finds a's relationGetRefAttributes: PROC[d: Domain] RETURNS[al: LIST OF Attribute];  -- returns all the attributes that can reference an entity from domain dRemoveAttribute: PROC[a: Attribute, al: AttributeList] RETURNS[AttributeList];  -- destructively removes a from alAppendAttributes: PROC [al1, al2: AttributeList] RETURNS [al: AttributeList];  -- destructively appends al1 and al2 and returns the result-- ***********************************************-- Opening segments and transactions for them -- ***********************************************SetUpSegment: PROC[   segmentFile: ROPE, seg: DB.Segment, number: NAT_ 0, makeReadOnly: BOOL_ FALSE ]  RETURNS [success: BOOL, readOnly: BOOL];  Do: PROC[  proc: PROC[ REF ANY ], clientData: REF ANY _ NIL,  reTry: BOOL _ FALSE, msgViewer: ViewerClasses.Viewer _ NIL ]  RETURNS [succeeded: BOOL];-- Evaluates the procedure supplied in an environment where the Aborted and Failed signals-- that may be raised from DB will be caught; the procedure will be retried after a restart-- if reTry is TRUE (otherwise a restart will be performed on failure without retrying the proc.-- Any messages produced will be printed in the msgViewer if one is supplied.-- We return succeeded=TRUE iff no errors occured in executing proc.TryRestart: PROC[trans: DB.Transaction];  -- Attempts to re-open an aborted transaction if user confirms.AtomFromSegment: PROC[ segR: ROPE ] RETURNS[ ATOM ];IsLocalName: PROC[ segR: ROPE ] RETURNS[ BOOL ];END.      Э╩▌  Ш JЪ┌╧cЫЬ╧k	ЬЮЬЮЬЮЬЮЬЮЬЮЬЮЬЮЬЮЬЮЬЭЩЬ╧nЬЮЬЮЬЮЬЯЬЮЬЮЬЮЬЯЬЮЬЮЬЭ"ЬЯЬЮЬЮЬЭ!ЬЯЬЮЬЮЬЮЬЭHЬЯЬЮЬЮЬЮЬЭNЬЯЬЮЬЮЬЮЬЭ:ЬЯ	ЬЮЬЮЬЮЬЮЬЭ;ЬЯЬЮЬЮЬЭЬЯЬЮЬЮЬЮЬЮЬЭIЬЯЬЮЬ"ЮЬЭ#ЬЯЬЮЬЮЬЭ<ЬЭХЬЯЬЮЬЮЬЮЬЮЬЮЬЮ
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