Query List Comprehensions

LFE supports QLCs for mnesia through the qlc macro. It has the same structure as a list comprehension and generates a Query Handle in the same way as with qlc:q([...]). The handle can be used together with all the combination functions in the module qlc.

For example:

  (lc ((<- (tuple k v) (ets:table e2)) (== k i)) v) {{Option}})

Macros, especially record macros, can freely be used inside query list comprehensions.

CAVEAT: Some things which are known not to work in the current version are nested QLCs and let/case/recieve which shadow variables.