- spans <- mapM (io . GHC.getHistorySpan s) took
- let nums = map (printf "-%-3d:") [(1::Int)..]
- let names = map GHC.historyEnclosingDecl took
- printForUser (vcat(zipWith3
- (\x y z -> x <+> y <+> z)
- (map text nums)
- (map (bold . ppr) names)
- (map (parens . ppr) spans)))
- io $ putStrLn $ if null rest then "<end of history>" else "..."
+ case hist of
+ [] -> io $ putStrLn $
+ "Empty history. Perhaps you forgot to use :trace?"
+ _ -> do
+ spans <- mapM (io . GHC.getHistorySpan s) took
+ let nums = map (printf "-%-3d:") [(1::Int)..]
+ names = map GHC.historyEnclosingDecl took
+ printForUser (vcat(zipWith3
+ (\x y z -> x <+> y <+> z)
+ (map text nums)
+ (map (bold . ppr) names)
+ (map (parens . ppr) spans)))
+ io $ putStrLn $ if null rest then "<end of history>" else "..."