The program:

x = v where v = 2 where

main = putStrLn "hello world"

parses as:

x = v where v = 2 main = putStrLn "hello world"

which is incorrect. (in general, the parser can't deal with empty where clauses) as in:

x = 'a' where class A a where

this gives a parse error because it's waiting for a real declaration inside of the first where clause. it also can't deal with empty statements:

v = do {return 'a';;}

should be accepted but results in a parser error. in Parser.ly, this essentially boils down to the fact that 'decllist' must be nonempty, but in certain circumstances (all?), it really *can* be empty. the last error (with statements), can be fixed by replacing line 637-639:

stmtlist :: { [HsStmt] } : '{' stmts '}' { $2 } | open stmts close { $2 }

with:

stmtlist :: { [HsStmt] } : '{' stmts optsemis '}' { $2 } | open stmts optsemis close { $2 }

i believe. - Hal -- Hal Daume III | hdaume@isi.edu "Arrest this man, he talks in maths." | www.isi.edu/~hdaume