If I write an instance of Semigroup with a horrible complexity for its operation (<>), will GHC know that mempty <> x = x x <> mempty = x and avoid computing (<>) ? I’m also interested in how you got that information, and, if this optimization does not exits, whether this could be done… Read More Does GHC optimize the monoid operation over mempty?
I have a row with 4 columns that are each 3 wide, which adds up to the 12 that are supposed the be in a row, but for some reason the last one is still going onto a new row. Any idea how to fix this? Here’s my code: <div class=”container text-center”> <h3>Welcome to “Ender’s… Read More Why is a column going into the next row when there are only 12 columns?
When I import the Day component into Week component (both are .tsx files), I get the following error: Uncaught Error: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: object. Check the render method of Week Day.tsx : import React from ‘react’; export default function Day… Read More TSX file can't render imported React Component
So I wrote a program to query a forex API (foreign exchange), and it works like a charm, but when I want to query every currency pair available, it evaluates all API calls as it takes a long time to execute but prints nothing. import Data.Functor ((<&>)) supportedPairs :: IO (Maybe [(String, String)]) forex ::… Read More Haskell mapM_ does not print