Thanks for the reply Ryan.
That's exactly the type of thing I was trying to do: use the
syntactical sugar of do-notation to express some replacement rules.
Why am I doing this?
A long time ago, when I was learning C, I did a small project
(spaghetti code) to encrypt text files in some
To take this a step further, if what you really want is the syntax sugar
for do-notation (and I understand that, I love sweet, sweet syntactical
sugar), you are probably implementing a Writer monad over some monoid.
Here's two data structures that can encode this type;
data Replacer1 k a =
A couple typos:
instance Monad Replacer1 where
-
instance Monad (Replacer1 k) where
instance Monad Replacer2 k where
-
instance Monad (Replacer2 k) where
I haven't tested any of this code, so you may have to fix some minor type
errors.
On Mon, Jul 30, 2012 at 10:38 PM, Ryan Ingram
As for understanding monads, you can try to define the State monad
[1]. Not sure if it's the best example but it's intuitive in that it
let's you thread a state behind the scenes.
***
Not related to your question -- in your example if you want to
translate characters but do not plan to change
Hello.
I'm trying to understand Monads. In order to do so, I decided to
create my own Monad for a simple domain-specific language.
The idea is to define a way to describe a multi-value replacement
inside do-notation.
Example of a function doing what I want (without Monads):
replaceAll :: (a -
On 07/28/2012 03:35 PM, Thiago Negri wrote:
[...]
As Monads are used for sequencing, first thing I did was to define the
following data type:
data TableDefinition a = Match a a (TableDefinition a) | Restart
So TableDefinition a is like [(a, a)].
[...]
So, to create a replacement table:
