Hello again, The proposal below succeeded by majority as well as by explicit confirmation from the core libraries committee, and has landed in GHC HEAD as of http://git.haskell.org/ghc.git/commit/393b820233caa00e428affc28e090b496d1816... * Discussion Details This proposal had the proponents below: - Anthony Cowley +1 - Carter Schonwald +1 - Daniel Díaz Casanueva +1 - Edward Kmett +1 - Herbert Valerio Riedel +1 - Ivan Lazar Miljenovic +1 - Johan Tibell +1 - John Lato +1 - Michael Snoyman +1 - Sergei Trofimovich +1 as well as the following explicit opponents: - Andreas Abel -0.5 (past 2-week-period) - Ben Millwood -1 - Malcolm Wallace -1(?) (past 2-week-period) as well as discussion participants with no explicit vote I could discern: - Bardur Arantsson ? - Daniel Trstenjak ? - David Feuer ? - Evan Laforge ? - Henning Thielemann ? - Niklas Haas ? One of the concerns raised during the discussion was that the type name 'Word' had been poorly chosen. A suggestion was made to rename Word to `UInt{,8,16,32,64}` and provide type-synonyms for backward compatibility. Other naming suggestions that came up were 'Nat' (imitating 'Int'/'Integer') or 'Cardinal'. The other concern against promoting 'Word' into the default namespace was the semantics of 'Word' due to '-' being prone to underflows (like 'Int', but at a different boundary), in combination with 'Word' being of under-specified precision (in GHC, however, 'Word' is effectively pointer-sized). Malcolm noted, the semantic aspect of a bounded 'Word' (as well as 'Int') was controversial since its inception. Please read the discussion thread in its entirety for the original voices and other concerns I may not have properly articulated here (in which case I'm sorry). Cheers, hvr On 2014-08-09 at 13:38:03 +0200, Herbert Valerio Riedel wrote:
Hello *,
Proposal --------
I hereby propose to export Haskell2010's Data.Word.Word type from the Prelude
Motivation ----------
Starting with Haskell2010, "Data.Word" exporting the type 'Word', "an unsigned integral type, with the same size as 'Int'" became part of the Haskell Report.
'Word' is usually a better choice than 'Int' when non-negative quantities (such as list lengths, bit or vector indices, or number of items in a container) need to be represented. Currently however, 'Word' is at a disadvantage (with respect to 'Int') in terms of public exposure by being accessible only after an "import Data.Word".
Moreover, since 'Word' is now part of the Haskell Report, libraries should attempt to avoid name-clashing with 'Word' (and if they do, it ought to be a conscious decision, which ought to be declared by a requiring a "import Prelude hiding (Word)"). While one might think 'Word' would be a popular type-name to use in Haskell code, the current level of name collision is still rather low (as is shown in the next section), so the cost would still be bearable at this point in my opinion.
Due diligence (w.r.t. code breakage impact) -------------------------------------------
Packages depending on `haskell2010` or `haskell98` are not affected, and neither would be those depending on `base` with a PVP-suggested upper bound.
However, to get a rough idea how widespread the use of 'Word' as a type on Hackage currently is, here's a simple check for current uses of 'Word' as a type-name performed with the simple heuristic search
find -name '*.*hs*' -exec grep \ '\(data\|newtype\|type\)[[:space:]]\+Word[ =]' {} +
over the unpacked source trees of the latest versions of the current 6766 packages on Hackage resulted in the following 43 packages being possibly affected (see specific source-code matches at end of email[1]):
1 adict-0.4.1 2 boxes-0.1.3 3 cjk-0.1.0.1 4 clash-prelude-0.5.1 5 combinat-0.2.5.0 6 concraft-pl-0.7.1 7 Craft3e-0.1.0.10 8 crf-chain1-0.2.2 9 crf-chain1-constrained-0.3.0 10 crf-chain2-generic-0.3.0 11 crf-chain2-tiers-0.2.1 12 delta-h-0.0.3 13 eros-0.6.0.0 14 estimators-0.1.4 15 estreps-0.3.1 16 FermatsLastMargin-0.1 17 fsmActions-0.4.4 18 gf-3.6 19 happraise-0.1 20 HAppS-Data-0.9.3 21 happstack-contrib-0.2.1 22 hist-pl-fusion-0.5.3 23 Holumbus-Searchengine-1.2.3 24 integer-pure-1.0 25 ixset-typed-0.3 26 language-bash-0.6.0 27 language-sh-0.0.3.1 28 lhc-0.10 29 MemoTrie-0.6.2 30 mpppc-0.1.3 31 nerf-0.5.2 32 regex-deriv-0.0.4 33 regex-pderiv-0.1.3 34 regexpr-symbolic-0.5 35 remote-0.1.1 36 soyuz-0.0.0 37 text-icu-0.6.3.7 38 text-register-machine-0.4.0 39 utf8-light-0.4.2 40 WordNet-1.1.0 41 WordNet-ghc74-0.1.3 42 xhaskell-library-0.0.6 43 york-lava-0.2
Discussion period -----------------
2 weeks
Footnotes ---------
[1] More specifically, here's the output of the above mentioned `grep` command:
adict-0.4.1/src/NLP/Adict/Core.hs:type Word a = V.Vector a boxes-0.1.3/Text/PrettyPrint/Boxes.hs:data Word = Word { wLen :: Int, getWord :: String } cjk-0.1.0.1/CJK/Data/CEDICT.hs:data Word = Word { clash-prelude-0.5.1/src/CLaSH/Tutorial.hs:type Word = Signed 4 combinat-0.2.5.0/Math/Combinat/FreeGroups.hs:type Word a = [Generator a] concraft-pl-0.7.1/src/NLP/Concraft/Polish/Morphosyntax.hs:data Word = Word Craft3e-0.1.0.10/Chapter7.hs:type Word = String Craft3e-0.1.0.10/Index.hs:type Word = String crf-chain1-0.2.2/Data/CRF/Chain1/Dataset/External.hs:type Word a = S.Set a crf-chain1-constrained-0.3.0/src/Data/CRF/Chain1/Constrained/Dataset/External.hs:data Word a b = Word crf-chain2-generic-0.3.0/Data/CRF/Chain2/Generic/External.hs:data Word a b = Word { crf-chain2-tiers-0.2.1/src/Data/CRF/Chain2/Tiers/Dataset/External.hs:data Word a b = Word { delta-h-0.0.3/src/EvalSem.hs:type Word = String eros-0.6.0.0/src/Text/Eros/Message.hs:type Word = L.Text estimators-0.1.4/NLP/Probability/Example/Trigram.hs:newtype Word = Word T.Text estreps-0.3.1/src/Repeats.lhs:-- type Word = Int FermatsLastMargin-0.1/FLM/WikiPages.hs: newtype Word = Word String fsmActions-0.4.4/Data/FsmActions.hs:newtype Word sy = Word [sy] gf-3.6/lib/src/finnish/wordnet/FreqFin.hs:type Word = String gf-3.6/treebanks/susanne/SusanneFormat.hs:type Word = String gf-3.6/treebanks/talbanken/Format.hs:data Word = W {id :: Id, word :: String, pos :: Tag} happraise-0.1/Main.hs:type Word = String HAppS-Data-0.9.3/src/HAppS/Data/Atom.hs: newtype Word = Word String happstack-contrib-0.2.1/src/Happstack/Contrib/Atom.hs: newtype Word = Word String hist-pl-fusion-0.5.3/src/NLP/HistPL/Fusion.hs:type Word = T.Text Holumbus-Searchengine-1.2.3/src/Holumbus/Index/Common/BasicTypes.hs:type Word = String integer-pure-1.0/Data/Integer.hs:type Word = Int -- We fake the Word type, to avoid nasty conversions. ixset-typed-0.3/src/Data/IxSet/Typed.hs: > newtype Word = Word String language-bash-0.6.0/src/Language/Bash/Word.hs:type Word = [Span] language-sh-0.0.3.1/Language/Sh/Syntax.hs:type Word = [Lexeme] lhc-0.10/lib/base/src/Data/Word.hs:type Word = Word32 lhc-0.10/lib/base/src/GHC/Word.hs:data Word = W# Word# deriving (Eq, Ord) MemoTrie-0.6.2/src/Data/MemoTrie.hs:-- newtype Word :->: a = WordTrie ([Bool] :->: a) mpppc-0.1.3/src/Text/PrettyPrint/MPPPC/TwoDim/Combinators/Flow.hs:data Word s t = Printable s t => nerf-0.5.2/src/NLP/Nerf/Types.hs:type Word = T.Text regex-deriv-0.0.4/Text/Regex/Deriv/ByteString/BitCode.hs:type Word = S.ByteString regex-deriv-0.0.4/Text/Regex/Deriv/ByteString/Posix.lhs:> type Word = S.ByteString regex-pderiv-0.1.3/Text/Regex/PDeriv/ByteString/LeftToRight.lhs:> type Word = S.ByteString regex-pderiv-0.1.3/Text/Regex/PDeriv/ByteString/LeftToRightD.lhs:> type Word = S.ByteString regex-pderiv-0.1.3/Text/Regex/PDeriv/ByteString/Posix.lhs:> type Word = S.ByteString regex-pderiv-0.1.3/Text/Regex/PDeriv/ByteString/RightToLeft.lhs:> type Word = S.ByteString regex-pderiv-0.1.3/Text/Regex/PDeriv/ByteString/TwoPasses.lhs:> type Word = S.ByteString regex-pderiv-0.1.3/Text/Regex/PDeriv/String/LeftToRightD.lhs:> type Word = String regexpr-symbolic-0.5/RegExpr/RegExprOperations.lhs:> type Word a = [a] remote-0.1.1/examples/tests/Test-MapReduce.hs:type Word = String remote-0.1.1/examples/kmeans/KMeans3.hs:type Word = String soyuz-0.0.0/DCPU16/Instructions.hs:data Word text-icu-0.6.3.7/Data/Text/ICU/Break.hsc:data Word = Uncategorized -- ^ A \"word\" that does not fit into another text-register-machine-0.4.0/Language/TRM/Base.hs:newtype Word = W [Letter] deriving (Eq, Monoid) utf8-light-0.4.2/src/Codec/Binary/UTF8/Light.hs:data Word = W# Word# WordNet-1.1.0/NLP/WordNet/Types.hs:type Word = String WordNet-ghc74-0.1.3/NLP/WordNet/Types.hs:type Word = String xhaskell-library-0.0.6/Text/Regex/PDeriv/ByteString/LeftToRight.lhs:> type Word = S.ByteString xhaskell-library-0.0.6/Text/Regex/PDeriv/ByteString/Posix.lhs:> type Word = S.ByteString xhaskell-library-0.0.6/Text/Regex/PDeriv/ByteString/RightToLeft.lhs:> type Word = S.ByteString xhaskell-library-0.0.6/Text/Regex/PDeriv/ByteString/TwoPasses.lhs:> type Word = S.ByteString york-lava-0.2/modules/Lava/Prelude.hs:type Word n = Vec n Bit
-- "Elegance is not optional" -- Richard O'Keefe