On further digging I see that Pretty.ftext eventually uses unpackFS, but outputs it via hPutStr. So no problem in GHC. Alan On Sat, Jan 10, 2015 at 5:39 PM, Alan & Kim Zimmerman wrote:

While doing further round-trip testing, I cam across the following issue

Original source

module Deprecation {-# Deprecated ["This is a module \"deprecation\"", "multi-line"] #-} ( foo ) where

Pretty-printed AST via ppr

(L {examples/Deprecation.hs:(3,1)-(4,30)} (DeprecatedTxt (L {examples/Deprecation.hs:3:1-14} "{-# Deprecated") [ (L {examples/Deprecation.hs:3:17-50} {FastString: "This is a module \"deprecation\""}), (L {examples/Deprecation.hs:4:14-25} {FastString: "multi-line"})])))

output where the FastString is converted to a string via unpackFS

module Deprecation {-# Deprecated ["This is a module "deprecation"", "multi-line"] #-} ( foo ) where

So, the ppr (via Pretty.ftext) is able to reproduce the escape characters in original string, but unpackFS does not.

Is this a problem for anyone else?

Regards Aan