1 T9497a-run: T9497a-run.hs:2:8: error:
2 • Found hole: _main :: IO ()
3 Or perhaps ‘_main’ is mis-spelled, or not in scope
4 • In the expression: _main
5 In an equation for ‘main’: main = _main
6 • Relevant bindings include
7 main :: IO () (bound at T9497a-run.hs:2:1)
8 Valid substitutions include
9 main :: IO () (defined at T9497a-run.hs:2:1)
10 readLn :: forall a. Read a => IO a
11 (imported from ‘Prelude’ at T9497a-run.hs:1:1
12 (and originally defined in ‘System.IO’))
13 mempty :: forall a. Monoid a => a
14 (imported from ‘Prelude’ at T9497a-run.hs:1:1
15 (and originally defined in ‘GHC.Base’))
16 undefined :: forall a. GHC.Stack.Types.HasCallStack => a
17 (imported from ‘Prelude’ at T9497a-run.hs:1:1
18 (and originally defined in ‘GHC.Err’))