I need some help in figuring a compiler error which is really driving me nuts... I have the following type class:
While trying to compile the following code, which is enhanced version of read build on readMay from Safe package.
Following the (accepted) answer from this question, I am expecting the following to work: Prelude Text.Regex.Posix Text.Regex.Base.RegexLike Text.Regex.Posix.String> makeRegex \".*\"
When working with derived instances in Haskell, is it possible to derive functions for arbitrary types, or are we restricted to particular functions?开发者_如何学GoYou can derive instances of the foll
I wrote something like this: instance Functor (Eithe开发者_StackOverflow中文版r e) where fmap _ (Left a) = Left a
Is there some way (any way) to implement constraints in type classes? As an example of what I\'m talking about, suppose I want to implement a Group as a type class. So a type would be a group if ther
I\'ve been playing with newtype wrappers for my indexes to avoid 开发者_JAVA技巧bugs, and I have some code like this:
I\'m reading Real World Haskell Pg 151, and I\'ve stared at the following passage for over an hour: Recall that String is a synonym for
I am learning Haskell. I have created function which returns multiplication table up to \'n\' in base \'b\'. Numbers are padded to \'w\' digits. As the last step, I want to compute \'w\' automatically
I thought I would try modeling some numerical integration on vector quantities of different dimensionality, and figured that type classes were the way to go.I needed something to define the difference
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