This regarding GHC behaviour for literate Haskell programs in Bird
style. GHC expects a blank line between comment[1] and code.
Otherwise, during the literate pre-processor stage, the error
'unlit: Program line next to comment' is reported.
While above behaviour makes sense in general, there are situations
where one would like to place comments adjacent to code with no
intervening blank line. For example, in documenting a declaration
using Haddock (in standard, non-literate Haskell), as shown in
sections 3.1 and
3.2 of the Haddock User Guide, no blank line
separates comment and code.
beginning with '>'.