main = [1..]
Standard input is empty
[1 of 1] Compiling Main ( prog.hs, prog.o )
prog.hs:1:0:
Couldn't match expected type `IO a' against inferred type `[t]'
In the first argument of `GHC.TopHandler.runMainIO', namely `main'
When checking the type of the function `main'
Standard output is empty