-- to bother to check the number of args
--------------
- go_sel [arg] = exprIsTrivial arg -- I'm experimenting with making record selection
+ go_sel [arg] = exprIsCheap arg -- I'm experimenting with making record selection
go_sel other = False -- look cheap, so we will substitute it inside a
-- lambda. Particularly for dictionary field selection.
-- BUT: Take care with (sel d x)! The (sel d) might be cheap, but