我想使用参数化类型类。下面是我的源代码:Haskell类型类别中的模糊类型
class (CContext3D c k v) => CBuilder3D c a k v where
build3D :: c -> a -> String -> HSL HLangJS HLangJS
在编译时我收到以下错误:
Could not deduce (CBuilder3D c a k0 v0)
from the context: CBuilder3D c a k v
bound by the type signature for:
build3D :: CBuilder3D c a k v =>
c -> a -> String -> HSL HLangJS HLangJS
下面的代码工作正常:
class (CContext3D c KeyContext3D String) => CBuilder3D c a where
build3D :: c -> a -> String -> HSL HLangJS HLangJS
这怎么可能释放类的实例取决于k和v类型?