shithub: purgatorio

ref: b5bc6572b0a82c52ab04bcf25e1ed76700deb246
dir: /man/2/spree-gather/

.TH SPREE-GATHER 2
.SH NAME
Gatherengine \- module interface for pre-assembled groups.
.SH SYNOPSIS
.EX
implement Gatherengine;

include "spree.m";
include "spree/gather.m";
Clique, Member: import Spree;

init:			fn(m: Spree, c: ref Clique, argv: list of string, archived: int): string;
clienttype:	fn(): string;
maxmembers:	fn(): int;
propose:		fn(members: array of string): string;
start:			fn(members: array of ref Member, archived: int);
command:	fn(member: ref Member, c: string): string;
archive:		fn();
readfile:		fn(f: int, offset: big, n: int): array of byte;
.EE
.SH DESCRIPTION
When implementing a
.IR spree (2)
engine, it is common to have the requirement that a certain number
of members are grouped together before actually starting the
engine.
.I Spree
provides no support for this directly; instead the
.I gather
module acts as an intermediate layer: engines that wish
this functionality should implement the
.B Gatherengine
interface.
The
.I gather
module also provides facilities for the automatic suspension and resumption
of players, clique archival, and members that watch but do not
participate.
.PP
.B Init
is called first, with
.IR m ,
the
.I spree
module, and
.IR c ,
the new clique.
.I Argv
gives a list of arguments to the engine (the first being
the name of the engine itself);
.I archived
is non-zero if the engine has been restored from an archive.
If
.B init
returns a non-nil string, it is taken to describe an error, and the
engine will be discarded.
.B Maxmembers
should return the maximum number of members that the engine
can accept;
.B clienttype
should return the kind of client that is expected by the
engine (e.g.
.B cards
for a card game engine).
.PP
.B Propose
proposes that a clique consisting of
.I members
(the names of the proposed members)
be started. It returns an error string: if this is non-nil, then
the clique is not started, otherwise the proposed
members are accepted into the clique,
and
.B start
is called, where
.I members
is the array of actual members (corresponding to the
members passed to
.BR propose ),
and
.I archived
is non-zero if the clique is being restored from an archive
(same as passed to
.BR init ).
.PP
Once a clique has been successfully started,
.B command
is called when a member sends a command to the
engine;
.I member
has sent the command,
and
.I c
is the command itself.
.B Command
should return a non-nil error string if the command fails.
.PP
When a clique is being archived,
.B archive
will be called to request the engine to store all its
internal state into the object hierarchy (this is the moment,
for instance, to call
.BR cardlib->archive ).
.SH "SEE ALSO"
.IR spree (2) ,