#10980: Deriving Read instance from datatype with N fields leads to N^2 code size growth -------------------------------------+------------------------------------- Reporter: slyfox | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): Reid, interesting! So you think it's all in the code generation and closure construction. Can you give a simple test case, separate from `deriving Read` that demonstrates the phenomenon, with the monadic and applicative versions side by side, but with very different perf? That would help to focus our attention. Thanks Simon -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10980#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler