Schedule.mesa
Copyright Ó 1986, 1987 by Xerox Corporation. All rights reserved.
Christian LeCocq January 28, 1987 6:01:59 pm PST
Schedule provides two sets of procs to deal with time oriented objects. One for lists of timed values, the other for lists of timed actions to do.
Bertrand Serlet April 15, 1987 4:24:55 pm PDT
History management package
History: TYPE = LIST OF HistoryPt; --the event data representation. An History is time ordered.
HistoryPt:
TYPE =
RECORD [t: ps, v:
REAL];
CreateHistory:
PROC [t: ps, v:
REAL]
RETURNS [newHistory: History];
creates a one HistoryPt History.
KillHistory:
PROC [history: History];
destroys the history structure in order to improve GC.
AddToHistory:
PROC [oldHistory: History, t: ps, v:
REAL]
RETURNS [newHistory: History];
adds a new HistoryPt to oldHistory, and erases any HistoryPt with larger t. If you add in the middle of an History the "old Future" is forgotten.
ForgetBeginings:
PROC [oldHistory: History, t: ps]
RETURNS [newHistory: History];
destroys any HistoryPt with time less than t.
FirstTimeOfHistory:
PROC [history: History]
RETURNS [t: ps];
returns the first time of history.
NextTimeOfHistory:
PROC [history: History, t: ps]
RETURNS [tnext: ps ← -1];
returns the time of the HistoryPt following t in history.
LastTimeOfHistory:
PROC [history: History]
RETURNS [t: ps];
returns the last time of history
LastValueOfHistory:
PROC [history: History]
RETURNS [v:
REAL];
returns the last v of history
VFromHistory:
PROC [history: History, t: ps]
RETURNS [v:
REAL];
returns the interpolated value at t from history. ERROR if t is before the first time of history.
EnumerateHistory:
PROC [history: History, from, to: ps, action: HistoryProc]
RETURNS [invalidEnumeration:
BOOL ←
FALSE];
applies action to each HistoryPt which time lies between from and to.
HistoryProc: TYPE = PROC [t: ps, v: REAL] RETURNS [quit: BOOLEAN ← FALSE];
Schedule:
PROC [hList:
LIST
OF History]
RETURNS [lt:
LIST
OF ps];
returns the merged ordered list of all the times of all the History.
Agenda Gestion
Agenda: TYPE = REF AgendaRec;
AgendaRec:
PRIVATE
TYPE =
MONITORED
RECORD [
execute: ExecuteProc, --the proc to call for each event of the list
list: LIST OF Event, --the ordered list of refs to proceed
nbOfEvents: INT ← 0, --statistical purposes
data: REF ANY --whatever you want, I swear I won't touch it.
];
Event:
TYPE =
RECORD [
t: ps,
ref: REF ANY
];
ExecuteProc:
TYPE =
PROC [ref:
REF
ANY, t: ps, data:
REF
ANY];
Create
Agenda:
PROC [execute: ExecuteProc, data:
REF
ANY]
RETURNS [newAgenda: Agenda];
creates a new Agenda initialized with execute and data.
KillAgenda:
PROC [agenda: Agenda];
destroys the agenda structure in order to improve GC.
InsertInAgenda:
PROC [agenda: Agenda, ref:
REF
ANY, t: ps];
inserts a new event in place in the agenda. Avoids duplications. ERROR if t is before the first time of the event list, or if the agenda is NIL.
ExecuteAgenda:
PROC [agenda: Agenda]
RETURNS [lastTime: ps];
executes and consumes the agenda.list. Returns the time of the last event executed. Pass the data field of the agenda to the ExecuteProc.
END.