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. Dominic. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
