id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
186	parse . prettyPrint /= id	dom	nibro	"I've been generating Haskell using haskell-src-exts but the prettyprinter isn't 
producing what I would expect.

I would expect parse . prettyPrint == id i.e. the AST should be unchanged if 
you prettyprint it then parse it.

Here's an example generated expression:

App (App (Var (UnQual (Ident ""pay""))) (Var (UnQual (Ident ""tPD"")))) (App (Var 
(UnQual (Ident ""a""))) (InfixApp (App (Var (UnQual (Ident ""length""))) (Var 
(UnQual (Ident ""tOD"")))) (QVarOp (UnQual (Symbol ""+""))) (Lit (Int (-1)))))

Here's what prettyPrint produces:

pay tPD a length tOD + -1

Parsing it gives this (i.e. not the expression I first thought of):

InfixApp (App (App (App (App (Var (UnQual (Ident ""pay""))) (Var (UnQual 
(Ident ""tPD"")))) (Var (UnQual (Ident ""a"")))) (Var (UnQual (Ident ""length"")))) 
(Var (UnQual (Ident ""tOD"")))) (QVarOp (UnQual (Symbol ""+""))) (NegApp (Lit (Int 
1)))

I would have expected the prettyprinter to produce this:

pay tPD (a (length tOD + -1))

Do I have to write my own prettyprinter? Do I have to put in explicit 
parentheses? The latter seems unsatisfactory as my generated AST is unambiguous 
and bracketing ought to be part of the prettyprinter. The former would be quite 
a lot of code as there are many cases to consider.

"	bug report	closed	major	Blue Sky	prettyprinter	1.1.4	fixed