[project @ 2000-10-03 08:43:00 by simonpj]
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Adding generics SLPJ Oct 2000
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This big commit adds Hinze/PJ-style generic class definitions, based
on work by Andrei Serjantov. For example:
class Bin a where
toBin :: a -> [Int]
fromBin :: [Int] -> (a, [Int])
toBin {| Unit |} Unit = []
toBin {| a :+: b |} (Inl x) = 0 : toBin x
toBin {| a :+: b |} (Inr y) = 1 : toBin y
toBin {| a :*: b |} (x :*: y) = toBin x ++ toBin y
fromBin {| Unit |} bs = (Unit, bs)
fromBin {| a :+: b |} (0:bs) = (Inl x, bs') where (x,bs') = fromBin bs
fromBin {| a :+: b |} (1:bs) = (Inr y, bs') where (y,bs') = fromBin bs
fromBin {| a :*: b |} bs = (x :*: y, bs'') where (x,bs' ) = fromBin bs
(y,bs'') = fromBin bs'
Now we can say simply
instance Bin a => Bin [a]
and the compiler will derive the appropriate code automatically.
(About 9k lines of diffs. Ha!)
Generic related things
~~~~~~~~~~~~~~~~~~~~~~
* basicTypes/BasicTypes: The EP type (embedding-projection pairs)
* types/TyCon:
An extra field in an algebraic tycon (genInfo)
* types/Class, and hsSyn/HsBinds:
Each class op (or ClassOpSig) carries information about whether
it a) has no default method
b) has a polymorphic default method
c) has a generic default method
There's a new data type for this: Class.DefMeth
* types/Generics:
A new module containing good chunk of the generic-related code
It has a .hi-boot file (alas).
* typecheck/TcInstDcls, typecheck/TcClassDcl:
Most of the rest of the generics-related code
* hsSyn/HsTypes:
New infix type form to allow types of the form
data a :+: b = Inl a | Inr b
* parser/Parser.y, Lex.lhs, rename/ParseIface.y:
Deal with the new syntax
* prelude/TysPrim, TysWiredIn:
Need to generate generic stuff for the wired-in TyCons
* rename/RnSource RnBinds:
A rather gruesome hack to deal with scoping of type variables
from a generic patterns. Details commented in the ClassDecl
case of RnSource.rnDecl.
Of course, there are many minor renamer consequences of the
other changes above.
* lib/std/PrelBase.lhs
Data type declarations for Unit, :+:, :*:
Slightly unrelated housekeeping
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* hsSyn/HsDecls:
ClassDecls now carry the Names for their implied declarations
(superclass selectors, tycon, etc) in a list, rather than
laid out one by one. This simplifies code between the parser
and the type checker.
* prelude/PrelNames, TysWiredIn:
All the RdrNames are now together in PrelNames.
* utils/ListSetOps:
Add finite mappings based on equality and association lists (Assoc a b)
Move stuff from List.lhs that is related
66 files changed: