module DerivingDrift.StandardRules (standardRules,driftResolvedNames) where
import DerivingDrift.RuleUtils
import Name.Prim
import Name.Name
import qualified Data.Map as Map
standardRules :: Map.Map Name.Name.Name (Data -> Doc)
standardRules = Map.fromList [
(class_Eq,eqfn),
(class_Ord,ordfn),
(class_Enum,enumfn),
(class_Show,showfn),
(class_Read,readfn),
(class_Bounded,boundedfn)]
driftResolvedNames :: [(Name.Name.Name,[Name.Name.Name])]
driftResolvedNames = map unkn stdCls ++ map self stdCls ++ map self stdVals
where unkn n = (toName UnknownType (q n), [n])
self n = (n,[n])
stdCls = Map.keys standardRules
stdVals = [v_sub,v_compose,
dc_True,dc_False,v_and,
dc_EQ,v_equals,v_geq,v_gt,v_compare,
dc_Pair,
dc_EmptyList,dc_Cons,v_foldl,v_cat,v_drop,
v_showsPrec,v_showParen,v_showChar,v_showString,
v_readsPrec,v_readParen,v_lex,
v_fromEnum,v_toEnum,v_enumFrom,v_enumFromThen,
v_minBound,v_maxBound]
q,u :: Name.Name.Name -> String
q = snd . fromName
u = getIdent
eqfn = instanceSkeleton (q class_Eq) [(makeEq,defaultEq)]
makeEq :: IFunction
makeEq (Body{constructor=constructor,types=types})
| null types = hsep $ texts [constructor,u v_equals,constructor, "=", q dc_True]
| otherwise = let
v = varNames types
v' = varNames' types
d x = parens . hsep $ text constructor : x
head = [ text (u v_equals), d v', text "="]
body = sepWith (text $ q v_and) $
zipWith (\x y -> (x <+> text (q v_equals) <+> y)) v v'
in d v <+> fsep (head ++ body)
defaultEq = hsep $ texts ["_", u v_equals, "_", "=" ,q dc_False]
ordfn d = let
ifn = [f c c'
| c <- zip (body d) [1 :: Int ..]
, c' <- zip (body d) [1 :: Int ..]]
cmp n n' = show $ compare n n'
f (b,n) (b',n')
| null (types b) = text (u v_compare) <+>
fsep [text (constructor b),
pattern (constructor b') (types b')
, char '=', text $ cmp n n' ]
| otherwise = let
head = fsep [l,r, char '=']
l = pattern (constructor b) (types b)
r = pattern' (constructor b') (types b')
one x y = fsep [text (q v_compare),x,y]
list [x] [y] = one x y
list xs ys = fsep [text (q v_foldl), parens fn, text (q dc_EQ),
bracketList (zipWith one xs ys)]
fn = fsep $ texts ["\\x y", "->", "if", "x", q v_equals, q dc_EQ,
"then", q v_compare, "y", q dc_EQ, "else", "x"]
in if constructor b == constructor b' then
text (u v_compare) <+> fsep [head,
list (varNames $ types b) (varNames' $ types b')]
else text (u v_compare) <+> fsep [head,text (cmp n n')]
in simpleInstance (q class_Ord) d <+> text "where" $$ block ifn
showfn = instanceSkeleton (q class_Show) [(makeShow,empty)]
makeShow :: IFunction
makeShow (Body{constructor=constructor,labels=labels,types=types})
| null types = fnName <+> fsep [headfn,showString constructor]
| null labels = fnName <+> fsep [headfn,bodyStart, body]
| otherwise = fnName <+> fsep[headfn,bodyStart,recordBody]
where
fnName = text (u v_showsPrec)
headfn = fsep [char 'd',(pattern constructor types),equals]
bodyStart = fsep [text (q v_showParen),parens $ fsep [text "d",text (q v_geq),text "10"]]
body = parens . fsep $ sepWith s (c : b)
recordBody = parens $ fsep [c,comp,showChar '{',comp,
fsep (sepWith s' b'),comp,showChar '}']
c = showString constructor
b = map (\x -> fsep[text (q v_showsPrec), text "10", x]) (varNames types)
b' = zipWith (\x l -> fsep [showString l, comp, showString " = ", comp, x])
b (map getIdent labels)
s = fsep [comp,showChar ' ', comp]
s' = fsep [comp,showChar ',',comp]
showChar c = fsep [text (q v_showChar), text ('\'':c:"\'")]
showString s = fsep [text (q v_showString), doubleQuotes $ text s]
comp = text (q v_compose)
readfn d = simpleInstance (q class_Read) d <+> text "where" $$ readsPrecFn d
readsPrecFn d = let
fnName = text (u v_readsPrec)
bodies = vcat $ sepWith (text $ q v_cat) (map makeRead (body d))
in nest 4 $ fnName <+> fsep[char 'd', text "input", equals,bodies]
makeRead :: IFunction
makeRead (Body{constructor=constructor,labels=labels,types=types})
| null types = fsep [read0,text "input"]
| null labels = fsep [headfn,read,text "input"]
| otherwise = fsep [headfn,readRecord, text "input"]
where
headfn = fsep [text (q v_readParen), parens (text $ unwords ["d",q v_gt,"9"])]
read0 = lambda $ listComp (result rest) [lexConstr rest]
read = lambda . listComp (result rest)
$ lexConstr ip : ( map f (init vars) )
++ final (last vars)
f v = fsep [tup v ip, from,readsPrec, ip]
final v = [fsep[tup v rest,from,readsPrec,ip]]
readRecord = let
f lab v = [
fsep [tup (tshow $ show (toUnqualified lab)) ip,lex],
fsep [tup (text $ show "=") ip,lex],
fsep [tup v ip ,from,readsPrec,ip]]
openB = fsep [tup (text $ show "{") ip,lex]
closeB = fsep [tup (text $ show "}") rest,lex]
comma = [fsep [tup (text $ show ",") ip,lex]]
in lambda . listComp (result rest)
$ lexConstr ip : openB
: (concat . sepWith comma) (zipWith f labels vars)
++ [closeB]
lambda x = parens ( fsep [text "\\",ip,text "->",x])
listComp x ~(l:ll) = brackets . fsep . sepWith comma $
((fsep[x, char '|', l]) : ll)
result x = tup (pattern constructor vars) x
lexConstr x = fsep [tup (text $ show constructor) x, lex]
vars = varNames types
ip = text "inp"
rest = text "rest"
tup x y = parens $ fsep [x <> char ',', y]
lex = fsep[from,text (q v_lex),ip]
readsPrec = fsep [text (q v_readsPrec),text "10"]
from = text "<-"
tshow x = text (show x)
enumfn d = let
fromE = fromEnumFn d
toE = toEnumFn d
eFrom = enumFromFn d
in if any (not . null . types) (body d)
then commentLine $ text "Warning -- can't derive Enum for"
<+> text (getIdent $ name d)
else simpleInstance (q class_Enum) d <+> text "where"
$$ block (fromE ++ toE ++ [eFrom,enumFromThenFn])
fromEnumFn :: Data -> [Doc]
fromEnumFn (D{body=body}) = map f (zip body [0:: Int ..])
where
f (Body{constructor=constructor},x) = text (u v_fromEnum) <+> (fsep $
texts [constructor , "=", show x])
toEnumFn :: Data -> [Doc]
toEnumFn (D{body=body}) = map f (zip body [0 :: Int ..])
where
f (Body{constructor=constructor},x) = text (u v_toEnum) <+> (fsep $
texts [show x , "=", constructor])
enumFromFn :: Data -> Doc
enumFromFn D{body=body} = let
conList = bracketList . texts . map constructor $ body
bodydoc = fsep [char 'e', char '=', text (q v_drop),
parens (text (q v_fromEnum) <+> char 'e'), conList]
in text (u v_enumFrom) <+> bodydoc
enumFromThenFn :: Doc
enumFromThenFn = let
wrapper = fsep $ texts ["i","j","=","enumFromThen\'","i","j","(",
q v_enumFrom, "i", ")"]
eq1 = text "enumFromThen\'"
<+> fsep (texts ["_","_",u dc_EmptyList,"=",u dc_EmptyList])
eq2 = text "enumFromThen\'"
<+> fsep (texts ["i","j","(x",u dc_Cons,"xs)","="])
<+> fsep [hsep $ texts [
"let", "d", "=",
q v_fromEnum,"j",q v_sub,q v_fromEnum,"i"],
text "in" <+> fsep (texts [
"x",u dc_Cons,"enumFromThen\'","i","j","(", q v_drop]
++ [parens . hsep $ texts ["d",q v_sub,"1"]]
++ [text "xs",text ")"])]
in text (q v_enumFromThen) <+> wrapper $$ block [text "where",eq1,eq2]
boundedfn d@D{name=name,body=body,derives=derives}
| all (null . types) body = boundedEnum d
| singleton body = boundedSingle d
| otherwise = commentLine $ text "Warning -- can't derive Bounded for"
<+> (text $ getIdent name)
boundedEnum d@D{body=body} = let f = constructor . head $ body
l = constructor . last $ body
in simpleInstance (q class_Bounded) d <+> text "where" $$ block [
hsep (texts [u v_minBound,"=",f]),
hsep (texts [u v_maxBound,"=",l])]
boundedSingle d@D{body=body} = let f = head $ body
in simpleInstance (q class_Bounded) d <+> text "where" $$ block [
hsep . texts $ [u v_minBound,"=",constructor f] ++
replicate (length (types f)) (q v_minBound),
hsep . texts $ [u v_maxBound,"=",constructor f] ++
replicate (length (types f)) (q v_maxBound)]
singleton [x] = True
singleton _ = False