Contexts are the groups into which rules are partitioned. The context
default-context
always exists. Contexts are defined by:
<context> ::=
(defcontext <context-name>
[:strategy <CRS>]
[:auto-return t | nil]
[:meta <meta-actions>])
where
<context-name>
is a symbol,
<CRS>
is a conflict resolution strategy defaulting to
(priority recency order)
(see below). If
:auto-return
is set to
t
(the default) then when the context has no more rules to fire, control passes to the next context on the agenda, but if it is
nil
an error occurs (a rule in the context should have issued a
(return)
instruction explicitly). The
:meta
option is necessary only if the default behaviour of the context is to be modified and is explained in Meta Rule Protocol.