Here is the implementation: http://hpaste.org/49733 I'd appreciate sanity checking. The way this works is that if a function is not mentioned here, we use the lazy version. All strict functions assume both maps are strict on input, and are maximally lazy because of this (for example, "strict" union will not inspect any values, because both input maps have fully evaluated values.) Cheers, Edward Excerpts from Edward Z. Yang's message of Sat Jul 30 23:43:09 -0400 2011:

Tallying informal votes, it appears we are +5 in favor of Strict and Lazy modules with the same underlying representation, with deprecation of strict methods in Data.IntMap.

I will be implementing this at Hac Phi tomorrow.

Cheers, Edward