[rules-dev] Hilog support for query literals

Hilog supports something called "generic programs". You can think of these as query literals you can pass around and call, bit like function literals. Because Hilog is untyped it uses a separate parenthesis to allow query literals to be passed: http://www.cs.sunysb.edu/~warren/xsbbook/node46.html "... snip .... closure(R)(X,Y) :- R(X,Y). closure(R)(X,Y) :- R(X,Z), closure(R)(Z,Y). Now given any binary relation, one can use use this definition to compute its closure. For example, we can define a binary predicate, |parent| as follows: :- hilog parent. parent(able,adam). parent(able,eve). parent(cain,adam). parent(cain,eve). etc and then we can use the generic definition of closure to find anscestors: | ?- clo ... snip ...." We could supprt this if we added generics to our query literals, probably something like: query closure( Query<String, String> q, String x, String y ) q( x, y ) or ( q( x, z ) and q(z, y) ) end Anyway something worth thinking on, when we start to look at function literal support in Drools, we should probably address the two at the same time. Mark