Setting GHCi prompt inside multiline blocks

You can't use prompt2 for GHC 8.2.1 and newer anymore because interface is changed. Previously it was:

   :set prompt <prompt>        set the prompt used in GHCi
   :set prompt2 <prompt>       set the continuation prompt used in GHCi

Now it's:

   :set prompt <prompt>        set the prompt used in GHCi
   :set prompt-cont <prompt>   set the continuation prompt used in GHCi
   :set prompt-function <expr> set the function to handle the prompt
   :set prompt-cont-function <expr> set the function to handle the continuation prompt

Some typical usages of these functions (just type in your GHCi or add in ~/.ghc/ghci.conf to apply settings globally):

:set prompt      λ: 
:set prompt-cont λ| 

or

:set prompt      ghci> 
:set prompt-cont ghci| 

Note: space at the end of each line

In GHC 7.8.1 and newer, you can change the continuation prompt using :set prompt2.

See GHC #7509.