Question

haskell code:

divisableBy3 :: [a] -> [a]
divisableBy3 v = filter odd(filter(\v -> v 'mod' 3 == 0))

Goal to filter all numbers in a list and then filter to keep only the ones divisbable by 3.
getting an error:

error:
* Syntax error on 'mod'
Perhaps you intended to use TemplateHaskell or TemplateHaskellQuotes
* In the Template Haskell quotation 'mod'
|
7 | divisableBy3 v = filter odd(filter(\v -> v 'mod' 3 == 0))
| ^^^^^

how to fix it ?

Also, can you use the (&&) or (||) operators in the filtering? for example if I wanted the it to filter the numbers that are divisible by 3 and the numbers divisible by 6, is that possible to do inside the Parentheses ?

Answer 1

You should have written mod using `` and not ''

Hence the correct code is

divisableBy3 v = filter odd(filter(\v -> v `mod` 3 == 0))