diff --git a/README.md b/README.md --- a/README.md +++ b/README.md @@ -1,1 +1,39 @@ # d10 + +Data types representing the digits zero through nine. + +## Modules + +Each of the following modules defines a different type named +`D10`, all of which are different representations of the same +concept: + +* `Data.D10.Char` - Defines a `D10` type as a newtype for `Char`, + where the values are restricted to characters between `'0'` and + `'9'`. +* `Data.D10.Num` - Defines a `D10` type as a newtype for any + type with an instance of the `Num` class, where the values + are restricted to numbers between `fromInteger 0` and + `fromInteger 9`. +* `Data.D10.Safe` - Defines a `D10` type as + `D0 | D1 | D2 | ... | D9`. + +Other modules: + +* `Data.D10.Predicate` - Functions to test whether values of + various types represent digits in the range *0* to *9*. + +## Quasi-quoters + +Each module that defines a `D10` type also defines quasi-quoters +for it. With the `QuasiQuotes` GHC extension enabled, a single +digit like *7* can be written as `[d10|7|]`, and a list of digits +like *[4,5,6]* can be written as `[d10|456|]`. For `Data.D10.Char` +and `Data.D10.Num`, the quasi-quoters are an important feature, +because the `D10` types defined in these modules have unsafe +constructors, and the quasi-quoters provide compile-time assurance +that we never construct a `D10` that represents a value outside +the range *0* to *9*. For `Data.D10.Safe`, the quasi-quoter is +offered merely as a possible convenience, allowing you to write +`[d10|456789|]` in place of the somewhat longer expression +`[D4,D5,D6,D7,D8,D9]`. diff --git a/d10.cabal b/d10.cabal --- a/d10.cabal +++ b/d10.cabal @@ -1,5 +1,5 @@ name: d10 -version: 0.1.0.0 +version: 0.1.0.1 category: Data synopsis: Digits 0-9 diff --git a/src/Data/D10/Char.hs b/src/Data/D10/Char.hs --- a/src/Data/D10/Char.hs +++ b/src/Data/D10/Char.hs @@ -77,7 +77,7 @@ -- template-haskell import Language.Haskell.TH (ExpQ, Q) -import Language.Haskell.TH.Quote (QuasiQuoter (QuasiQuoter)) +import Language.Haskell.TH.Quote (QuasiQuoter (..)) import Language.Haskell.TH.Syntax (Lift (lift)) -- $setup @@ -693,9 +693,6 @@ --------------------------------------------------- -qq :: Lift a => (String -> Q a) -> QuasiQuoter -qq f = QuasiQuoter (f >=> lift) undefined undefined undefined - -- | A single base-10 digit. -- -- This quasi-quoter, when used as an expression, produces a @@ -715,7 +712,12 @@ -- ... d10 :: QuasiQuoter -d10 = qq strD10Fail +d10 = QuasiQuoter + { quoteExp = strD10Fail >=> lift + , quotePat = \_ -> fail "d10 cannot be used in a pattern context" + , quoteType = \_ -> fail "d10 cannot be used in a type context" + , quoteDec = \_ -> fail "d10 cannot be used in a declaration context" + } -- | A list of base-10 digits. -- @@ -737,4 +739,9 @@ -- ... d10list :: QuasiQuoter -d10list = qq strD10ListFail +d10list = QuasiQuoter + { quoteExp = strD10ListFail >=> lift + , quotePat = \_ -> fail "d10list cannot be used in a pattern context" + , quoteType = \_ -> fail "d10list cannot be used in a type context" + , quoteDec = \_ -> fail "d10list cannot be used in a declaration context" + } diff --git a/src/Data/D10/Num.hs b/src/Data/D10/Num.hs --- a/src/Data/D10/Num.hs +++ b/src/Data/D10/Num.hs @@ -81,7 +81,7 @@ -- template-haskell import Language.Haskell.TH (ExpQ, Q) -import Language.Haskell.TH.Quote (QuasiQuoter (QuasiQuoter)) +import Language.Haskell.TH.Quote (QuasiQuoter (..)) import Language.Haskell.TH.Syntax (Lift (lift)) -- $setup @@ -696,9 +696,6 @@ --------------------------------------------------- -qq :: Lift a => (String -> Q a) -> QuasiQuoter -qq f = QuasiQuoter (f >=> lift) undefined undefined undefined - -- | A single base-10 digit. -- -- This quasi-quoter, when used as an expression, produces a @@ -718,7 +715,12 @@ -- ... d10 :: forall a. (Lift a, Num a) => QuasiQuoter -d10 = qq @(D10 a) strD10Fail +d10 = QuasiQuoter + { quoteExp = strD10Fail >=> lift @(D10 a) + , quotePat = \_ -> fail "d10 cannot be used in a pattern context" + , quoteType = \_ -> fail "d10 cannot be used in a type context" + , quoteDec = \_ -> fail "d10 cannot be used in a declaration context" + } -- | A list of base-10 digits. -- @@ -740,4 +742,9 @@ -- ... d10list :: forall a. (Lift a, Num a) => QuasiQuoter -d10list = qq @[D10 a] strD10ListFail +d10list = QuasiQuoter + { quoteExp = strD10ListFail >=> lift @[D10 a] + , quotePat = \_ -> fail "d10list cannot be used in a pattern context" + , quoteType = \_ -> fail "d10list cannot be used in a type context" + , quoteDec = \_ -> fail "d10list cannot be used in a declaration context" + } diff --git a/src/Data/D10/Safe.hs b/src/Data/D10/Safe.hs --- a/src/Data/D10/Safe.hs +++ b/src/Data/D10/Safe.hs @@ -81,7 +81,7 @@ -- template-haskell import Language.Haskell.TH (ExpQ, Q) -import Language.Haskell.TH.Quote (QuasiQuoter (QuasiQuoter)) +import Language.Haskell.TH.Quote (QuasiQuoter (..)) import Language.Haskell.TH.Syntax (Lift (lift)) -- $setup @@ -730,9 +730,6 @@ --------------------------------------------------- -qq :: Lift a => (String -> Q a) -> QuasiQuoter -qq f = QuasiQuoter (f >=> lift) undefined undefined undefined - -- | A single base-10 digit. -- -- This quasi-quoter, when used as an expression, produces a @@ -752,7 +749,12 @@ -- ... d10 :: QuasiQuoter -d10 = qq strD10Fail +d10 = QuasiQuoter + { quoteExp = strD10Fail >=> lift + , quotePat = \_ -> fail "d10 cannot be used in a pattern context" + , quoteType = \_ -> fail "d10 cannot be used in a type context" + , quoteDec = \_ -> fail "d10 cannot be used in a declaration context" + } -- | A list of base-10 digits. -- @@ -774,4 +776,9 @@ -- ... d10list :: QuasiQuoter -d10list = qq strD10ListFail +d10list = QuasiQuoter + { quoteExp = strD10ListFail >=> lift + , quotePat = \_ -> fail "d10list cannot be used in a pattern context" + , quoteType = \_ -> fail "d10list cannot be used in a type context" + , quoteDec = \_ -> fail "d10list cannot be used in a declaration context" + }