SPREE-GATHER(2) SPREE-GATHER(2)
NAME
Gatherengine - module interface for pre-assembled groups.
SYNOPSIS
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;
DESCRIPTION
When implementing a spree(2) engine, it is common to have
the requirement that a certain number of members are grouped
together before actually starting the engine. Spree pro-
vides no support for this directly; instead the gather mod-
ule acts as an intermediate layer: engines that wish this
functionality should implement the Gatherengine interface.
The gather module also provides facilities for the automatic
suspension and resumption of players, clique archival, and
members that watch but do not participate.
Init is called first, with m, the spree module, and c, the
new clique. Argv gives a list of arguments to the engine
(the first being the name of the engine itself); archived is
non-zero if the engine has been restored from an archive.
If init returns a non-nil string, it is taken to describe an
error, and the engine will be discarded. Maxmembers should
return the maximum number of members that the engine can
accept; clienttype should return the kind of client that is
expected by the engine (e.g. cards for a card game engine).
Propose proposes that a clique consisting of 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 start is called, where members is the array
of actual members (corresponding to the members passed to
propose), and archived is non-zero if the clique is being
restored from an archive (same as passed to init).
Once a clique has been successfully started, command is
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SPREE-GATHER(2) SPREE-GATHER(2)
called when a member sends a command to the engine; member
has sent the command, and c is the command itself. Command
should return a non-nil error string if the command fails.
When a clique is being archived, 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
cardlib->archive).
SEE ALSO
spree(2),
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