For with a step in Haskell

In Haskell, the for function is used to iterate over a range of values. The function takes three arguments:

1. The starting value of the range
2. The ending value of the range
3. A function to be applied to each value in the range

The syntax for the for function is as follows:

for :: Monad m => a -> a -> (a -> m ()) -> m ()

Here's an example of how to use the for function:

import Control.Monad
main = forM_ [1..5] $ \i -> do

  putStrLn $ "Iteration " ++ show i

In this example, the forM_ function is used instead of for. The forM_ function is a monadic version of the for function and is often preferred in Haskell. The first argument to forM_ is the range of values to iterate over ([1..5]), the second argument is a function to apply to each value, and in this case, it's an anonymous function that prints a message to the console with the iteration number.

The output of running this program would look like this:

Iteration 1
Iteration 2
Iteration 3
Iteration 4
Iteration 5

Note that the show function is used to convert the integer value of i to a string so that it can be concatenated with the message string in the putStrLn function.