#11349: [TypeApplications] Create Proxy-free alternatives of functions in base -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Core Libraries | Version: 7.10.3 Resolution: | Keywords: | TypeApplications Operating System: Other | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by rwbarton): Replying to [comment:4 Iceland_jack]:
For the '''''T'''angent '''o'''f '''t'''he '''D'''ay'' ('''''a'''s '''a''' '''S'''ervice'') (''TotD''(''aaS'')), how should the inclusion of Natural in base influence functions and other libraries?
Off-topic, but...
Functions like `length`, `take`, `drop`, `splitAt`, `replicate` scream for natural numbers as their arguments: Their types are of course well established, `Int` is also fixed- while `Natural` is arbitrary-precision. Is `Word` suitable? Maybe not worth it.
Very unsuitable as long as subtraction on Word has wrap-around behavior rather than erroring. You would fail to catch a lot of programming errors that way, when passing wrapped values to functions that used to check whether their argument was negative, and in other cases you would silently change program behavior, when using functions that used to treat negative values as 0. See http://www.wabbo.org/blog/2014/22aug_on_bananas.html for a related example from Rust. Word is basically useless as an "efficient small-ish Natural" for this reason, and only makes sense when you specifically want the machine- specific wrap-around behavior, or when doing bit manipulation only. (And yes, Int can overflow too, making it somewhat less effective as an "efficient small-ish Integer", but overflowing an Int computation requires large inputs (which are often impossible to provide to the program in practice), while a Word computation can be overflowed with very small inputs.) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11349#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler