{-# LANGUAGE CPP, TemplateHaskell #-}
module Web.Routes.TH
( derivePathInfo
, derivePathInfo'
, standard
, mkRoute
) where
import Control.Applicative ((<$>))
import Control.Monad (ap, replicateM)
import Data.Char (isUpper, toLower, toUpper)
import Data.List (intercalate, foldl')
import Data.List.Split (split, dropInitBlank, keepDelimsL, whenElt)
import Data.Text (pack, unpack)
import Data.Typeable (typeOf)
import Language.Haskell.TH
import Language.Haskell.TH.Syntax (nameBase)
import Text.ParserCombinators.Parsec ((<|>),many1)
import Web.Routes.PathInfo
derivePathInfo :: Name
-> Q [Dec]
derivePathInfo :: Name -> Q [Dec]
derivePathInfo = ([Char] -> [Char]) -> Name -> Q [Dec]
derivePathInfo' [Char] -> [Char]
standard
derivePathInfo' :: (String -> String)
-> Name
-> Q [Dec]
derivePathInfo' :: ([Char] -> [Char]) -> Name -> Q [Dec]
derivePathInfo' [Char] -> [Char]
formatter Name
name
= do Class
c <- Name -> Q Class
parseInfo Name
name
case Class
c of
Tagged [(Name, Int)]
cons Cxt
cx [Name]
keys ->
do let context :: Q Cxt
context = forall (f :: * -> *) a. Applicative f => a -> f a
pure forall a b. (a -> b) -> a -> b
$ [ Type -> Type -> Type
AppT (Name -> Type
ConT ''PathInfo) (Name -> Type
VarT Name
key) | Name
key <- [Name]
keys ] forall a. [a] -> [a] -> [a]
++ Cxt
cx
Dec
i <- forall (m :: * -> *).
Quote m =>
m Cxt -> m Type -> [m Dec] -> m Dec
instanceD Q Cxt
context (Name -> [TypeQ] -> TypeQ
mkType ''PathInfo [Name -> [TypeQ] -> TypeQ
mkType Name
name (forall a b. (a -> b) -> [a] -> [b]
map forall (m :: * -> *). Quote m => Name -> m Type
varT [Name]
keys)])
[ [(Name, Int)] -> Q Dec
toPathSegmentsFn [(Name, Int)]
cons
, [(Name, Int)] -> Q Dec
fromPathSegmentsFn [(Name, Int)]
cons
]
forall (m :: * -> *) a. Monad m => a -> m a
return [Dec
i]
where
toPathSegmentsFn :: [(Name, Int)] -> DecQ
toPathSegmentsFn :: [(Name, Int)] -> Q Dec
toPathSegmentsFn [(Name, Int)]
cons
= do Name
inp <- forall (m :: * -> *). Quote m => [Char] -> m Name
newName [Char]
"inp"
let body :: Q Exp
body = forall (m :: * -> *). Quote m => m Exp -> [m Match] -> m Exp
caseE (forall (m :: * -> *). Quote m => Name -> m Exp
varE Name
inp) forall a b. (a -> b) -> a -> b
$
[ do [Name]
args <- forall (m :: * -> *) a. Applicative m => Int -> m a -> m [a]
replicateM Int
nArgs (forall (m :: * -> *). Quote m => [Char] -> m Name
newName [Char]
"arg")
let matchCon :: Q Pat
matchCon = forall (m :: * -> *). Quote m => Name -> [m Pat] -> m Pat
conP Name
conName (forall a b. (a -> b) -> [a] -> [b]
map forall (m :: * -> *). Quote m => Name -> m Pat
varP [Name]
args)
conStr :: [Char]
conStr = [Char] -> [Char]
formatter (Name -> [Char]
nameBase Name
conName)
forall (m :: * -> *).
Quote m =>
m Pat -> m Body -> [m Dec] -> m Match
match Q Pat
matchCon (forall (m :: * -> *). Quote m => m Exp -> m Body
normalB ([Char] -> [Name] -> Q Exp
toURLWork [Char]
conStr [Name]
args)) []
| (Name
conName, Int
nArgs) <- [(Name, Int)]
cons ]
toURLWork :: String -> [Name] -> ExpQ
toURLWork :: [Char] -> [Name] -> Q Exp
toURLWork [Char]
conStr [Name]
args
= forall (t :: * -> *) a. Foldable t => (a -> a -> a) -> t a -> a
foldr1 (\Q Exp
a Q Exp
b -> forall (m :: * -> *). Quote m => m Exp -> m Exp -> m Exp
appE (forall (m :: * -> *). Quote m => m Exp -> m Exp -> m Exp
appE [| (++) |] Q Exp
a) Q Exp
b) ([| [pack conStr] |] forall a. a -> [a] -> [a]
: [ [| toPathSegments $(varE arg) |] | Name
arg <- [Name]
args ])
forall (m :: * -> *). Quote m => Name -> [m Clause] -> m Dec
funD 'toPathSegments [forall (m :: * -> *).
Quote m =>
[m Pat] -> m Body -> [m Dec] -> m Clause
clause [forall (m :: * -> *). Quote m => Name -> m Pat
varP Name
inp] (forall (m :: * -> *). Quote m => m Exp -> m Body
normalB Q Exp
body) []]
fromPathSegmentsFn :: [(Name,Int)] -> DecQ
fromPathSegmentsFn :: [(Name, Int)] -> Q Dec
fromPathSegmentsFn [(Name, Int)]
cons
= do let body :: Q Exp
body = (forall (t :: * -> *) a. Foldable t => (a -> a -> a) -> t a -> a
foldl1 (\Q Exp
a Q Exp
b -> forall (m :: * -> *). Quote m => m Exp -> m Exp -> m Exp
appE (forall (m :: * -> *). Quote m => m Exp -> m Exp -> m Exp
appE [| (<|>) |] Q Exp
a) Q Exp
b)
[ Name -> Int -> Q Exp
parseCon Name
conName Int
nArgs
| (Name
conName, Int
nArgs) <- [(Name, Int)]
cons])
parseCon :: Name -> Int -> ExpQ
parseCon :: Name -> Int -> Q Exp
parseCon Name
conName Int
nArgs = forall (t :: * -> *) a. Foldable t => (a -> a -> a) -> t a -> a
foldl1 (\Q Exp
a Q Exp
b -> forall (m :: * -> *). Quote m => m Exp -> m Exp -> m Exp
appE (forall (m :: * -> *). Quote m => m Exp -> m Exp -> m Exp
appE [| ap |] Q Exp
a) Q Exp
b)
([| segment (pack $(stringE (formatter $ nameBase conName))) >> return $(conE conName) |]
forall a. a -> [a] -> [a]
: (forall a. Int -> a -> [a]
replicate Int
nArgs [| fromPathSegments |]))
forall (m :: * -> *). Quote m => Name -> [m Clause] -> m Dec
funD 'fromPathSegments [forall (m :: * -> *).
Quote m =>
[m Pat] -> m Body -> [m Dec] -> m Clause
clause [] (forall (m :: * -> *). Quote m => m Exp -> m Body
normalB Q Exp
body) []]
mkType :: Name -> [TypeQ] -> TypeQ
mkType :: Name -> [TypeQ] -> TypeQ
mkType Name
con = forall (t :: * -> *) b a.
Foldable t =>
(b -> a -> b) -> b -> t a -> b
foldl forall (m :: * -> *). Quote m => m Type -> m Type -> m Type
appT (forall (m :: * -> *). Quote m => Name -> m Type
conT Name
con)
data Class = Tagged [(Name, Int)] Cxt [Name]
parseInfo :: Name -> Q Class
parseInfo :: Name -> Q Class
parseInfo Name
name
= do Info
info <- Name -> Q Info
reify Name
name
case Info
info of
TyConI (DataD Cxt
cx Name
_ [TyVarBndr ()]
keys Maybe Type
_ [Con]
cs [DerivClause]
_) -> forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ [(Name, Int)] -> Cxt -> [Name] -> Class
Tagged (forall a b. (a -> b) -> [a] -> [b]
map Con -> (Name, Int)
conInfo [Con]
cs) Cxt
cx forall a b. (a -> b) -> a -> b
$ forall a b. (a -> b) -> [a] -> [b]
map forall {flag}. TyVarBndr flag -> Name
conv [TyVarBndr ()]
keys
TyConI (NewtypeD Cxt
cx Name
_ [TyVarBndr ()]
keys Maybe Type
_ Con
con [DerivClause]
_)-> forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ [(Name, Int)] -> Cxt -> [Name] -> Class
Tagged [Con -> (Name, Int)
conInfo Con
con] Cxt
cx forall a b. (a -> b) -> a -> b
$ forall a b. (a -> b) -> [a] -> [b]
map forall {flag}. TyVarBndr flag -> Name
conv [TyVarBndr ()]
keys
Info
_ -> forall a. HasCallStack => [Char] -> a
error ([Char]
"Unexpected " forall a. Semigroup a => a -> a -> a
<> forall a. Show a => a -> [Char]
show (forall a. Typeable a => a -> TypeRep
typeOf Info
info) forall a. Semigroup a => a -> a -> a
<> [Char]
": " forall a. Semigroup a => a -> a -> a
<> forall a. Show a => a -> [Char]
show Info
info)
where conInfo :: Con -> (Name, Int)
conInfo (NormalC Name
n [BangType]
args) = (Name
n, forall (t :: * -> *) a. Foldable t => t a -> Int
length [BangType]
args)
conInfo (RecC Name
n [VarBangType]
args) = (Name
n, forall (t :: * -> *) a. Foldable t => t a -> Int
length [VarBangType]
args)
conInfo (InfixC BangType
_ Name
n BangType
_) = (Name
n, Int
2)
conInfo (ForallC [TyVarBndr Specificity]
_ Cxt
_ Con
con) = Con -> (Name, Int)
conInfo Con
con
#if MIN_VERSION_template_haskell(2,17,0)
conv :: TyVarBndr flag -> Name
conv (PlainTV Name
nm flag
_) = Name
nm
conv (KindedTV Name
nm flag
_ Type
_) = Name
nm
#else
conv (PlainTV nm) = nm
conv (KindedTV nm _) = nm
#endif
standard :: String -> String
standard :: [Char] -> [Char]
standard =
forall a. [a] -> [[a]] -> [a]
intercalate [Char]
"-" forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a b. (a -> b) -> [a] -> [b]
map (forall a b. (a -> b) -> [a] -> [b]
map Char -> Char
toLower) forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a. Splitter a -> [a] -> [[a]]
split Splitter Char
splitter
where
splitter :: Splitter Char
splitter = forall a. Splitter a -> Splitter a
dropInitBlank forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a. Splitter a -> Splitter a
keepDelimsL forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a. (a -> Bool) -> Splitter a
whenElt forall a b. (a -> b) -> a -> b
$ Char -> Bool
isUpper
mkRoute :: Name -> Q [Dec]
mkRoute :: Name -> Q [Dec]
mkRoute Name
url =
do (Tagged [(Name, Int)]
cons Cxt
_ [Name]
_) <- Name -> Q Class
parseInfo Name
url
Dec
fn <- forall (m :: * -> *). Quote m => Name -> [m Clause] -> m Dec
funD ([Char] -> Name
mkName [Char]
"route") forall a b. (a -> b) -> a -> b
$
forall a b. (a -> b) -> [a] -> [b]
map (\(Name
con, Int
numArgs) ->
do
[Name]
args <- forall (m :: * -> *) a. Applicative m => Int -> m a -> m [a]
replicateM Int
numArgs (forall (m :: * -> *). Quote m => [Char] -> m Name
newName [Char]
"arg")
forall (m :: * -> *).
Quote m =>
[m Pat] -> m Body -> [m Dec] -> m Clause
clause [forall (m :: * -> *). Quote m => Name -> [m Pat] -> m Pat
conP Name
con forall a b. (a -> b) -> a -> b
$ forall a b. (a -> b) -> [a] -> [b]
map forall (m :: * -> *). Quote m => Name -> m Pat
varP [Name]
args] (forall (m :: * -> *). Quote m => m Exp -> m Body
normalB forall a b. (a -> b) -> a -> b
$ forall (t :: * -> *) b a.
Foldable t =>
(b -> a -> b) -> b -> t a -> b
foldl' forall (m :: * -> *). Quote m => m Exp -> m Exp -> m Exp
appE (forall (m :: * -> *). Quote m => Name -> m Exp
varE ([Char] -> Name
mkName ([Char] -> [Char]
headLower (Name -> [Char]
nameBase Name
con)))) (forall a b. (a -> b) -> [a] -> [b]
map forall (m :: * -> *). Quote m => Name -> m Exp
varE [Name]
args)) []
) [(Name, Int)]
cons
forall (m :: * -> *) a. Monad m => a -> m a
return [Dec
fn]
where
headLower :: String -> String
headLower :: [Char] -> [Char]
headLower (Char
c:[Char]
cs) = Char -> Char
toLower Char
c forall a. a -> [a] -> [a]
: [Char]
cs
parseMethods :: Name -> Q [Name]
parseMethods :: Name -> Q [Name]
parseMethods Name
con =
do Info
info <- Name -> Q Info
reify Name
con
case Info
info of
(DataConI Name
_ Type
ty Name
_) ->
do forall a. IO a -> Q a
runIO forall a b. (a -> b) -> a -> b
$ forall a. Show a => a -> IO ()
print Type
ty
forall a. IO a -> Q a
runIO forall a b. (a -> b) -> a -> b
$ forall a. Show a => a -> IO ()
print forall a b. (a -> b) -> a -> b
$ Type -> Type
lastTerm Type
ty
forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ Type -> [Name]
extractMethods (Type -> Type
lastTerm Type
ty)
extractMethods :: Type -> [Name]
Type
ty =
case Type
ty of
(AppT (ConT Name
con) (ConT Name
method)) ->
[Name
method]
(AppT (ConT Name
con) Type
methods) ->
Type -> [Name]
extractMethods' Type
methods
where
extractMethods' :: Type -> [Name]
extractMethods' :: Type -> [Name]
extractMethods' Type
t = forall a b. (a -> b) -> [a] -> [b]
map (\(ConT Name
n) -> Name
n) (Type -> Cxt
leafs Type
t)
lastTerm :: Type -> Type
lastTerm :: Type -> Type
lastTerm t :: Type
t@(AppT Type
l Type
r)
| Type -> Bool
hasArrowT Type
l = Type -> Type
lastTerm Type
r
| Bool
otherwise = Type
t
lastTerm Type
t = Type
t
hasArrowT :: Type -> Bool
hasArrowT :: Type -> Bool
hasArrowT Type
ArrowT = Bool
True
hasArrowT (AppT Type
l Type
r) = Type -> Bool
hasArrowT Type
l Bool -> Bool -> Bool
|| Type -> Bool
hasArrowT Type
r
hasArrowT Type
_ = Bool
False
leafs :: Type -> [Type]
leafs :: Type -> Cxt
leafs (AppT l :: Type
l@(AppT Type
_ Type
_) Type
r) = Type -> Cxt
leafs Type
l forall a. [a] -> [a] -> [a]
++ Type -> Cxt
leafs Type
r
leafs (AppT Type
_ Type
r) = Type -> Cxt
leafs Type
r
leafs Type
t = [Type
t]