#15720: Assign to literals is allowed in ghci -------------------------------------+------------------------------------- Reporter: sighingnow | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: GHCi | Version: 8.6.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: GHC accepts | Unknown/Multiple invalid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott): Replying to [comment:2 sighingnow]:
Should we enable `-Wunused-pattern-binds` by default ?
It's enabled by `-Wall`: {{{ $ ghci -Wall GHCi, version 8.4.3: http://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/ryanglscott/.ghci λ> 1 = 2 <interactive>:1:1: warning: [-Wtype-defaults] • Defaulting the following constraints to type ‘Integer’ (Eq a0) arising from the literal ‘1’ at <interactive>:1:1 (Num a0) arising from the literal ‘1’ at <interactive>:1:1 • In the pattern: 1 In a pattern binding: 1 = 2 <interactive>:1:1: warning: [-Wunused-pattern-binds] This pattern-binding binds no variables: 1 = 2 }}} I'd be hesitant to enable `-Wunused-pattern-binds` by default without a clear community consensus for it (perhaps in the form of a GHC proposal). -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15720#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler