haskell - Hoogle 查询返回与类型签名不匹配的函数

Question

如果我尝试使用以下Hoogle命令（v4.2.33）来搜索包含类型签名的函数ByteString->[ByteString]：

hoogle --count 40 "ByteString->[ByteString]"

然后在输出结束时我得到：

Data.ByteString.Char8 transpose :: [ByteString] -> [ByteString]
Data.ByteString.Lazy transpose :: [ByteString] -> [ByteString]
Data.ByteString.Lazy.Char8 transpose :: [ByteString] -> [ByteString]
Codec.Compression.Zlib.Raw compress :: ByteString -> ByteString
Codec.Compression.GZip compress :: ByteString -> ByteString

ByteString -> ByteString当我将类型签名指定为时，为什么 Hoogle 会返回带有签名等的函数ByteString->[ByteString]？

Answer 1

Hoogle uses a concept of "approximate" type matching, generalizing types and stripping constructors to find close matches.