Brian Hulley wrote:
... I didn't realise that list comprehension syntax was not just a
sugar for the equivalent do expression but I see now that it is indeed
translated differently, bypassing monads altogether, which of course is
confusing but understandable if monads were only thought up after list
comprehensions were already in the language.
Here's the brief history with respect to this issue:
Apr 1990: Haskell Report 1.0, list comps, but no monads.
May 1996: Haskell Report 1.3, monads appear.
Apr 1997: Haskell Report 1.4, list comps made applicable to
arbitrary monads.
Feb 1999: Haskell 98 Report, list comps reverted to just lists.
-Paul
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