read "(3,'a')"::(Int, Char) returns expected tuple. But with ":: Int" leads to runtime exception, because it calls `readsPrec` of Int and can not parse such string. But readsPrec of (a,b) where both are readable parses it successfully. 12.07.2018 13:05, mrx wrote:
Hi,
I'm trying to make sense of the type class `Read`. It feels to be like a function performing casting to me, similar to what you have in C and Java.
The weird thing is that the casting doesn't have to make sense, type-wise. So `read "5" :: Int` produce the integer 5 which make sense but `read "(3,'a')" :: Int` doesn't make sense to me but ghci accepts it!
This is seeing Read as a function, as it's a type class i suspect I'm missing something. Quite possibly quite a lot...
Why is the type class called `Read`? What am I missing above?
// Patrik Iselind
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