#8353: Easy way to defer type errors -------------------------------------+------------------------------------- Reporter: goldfire | Owner: Type: feature | Status: new request | Milestone: Priority: normal | Version: 7.6.3 Component: GHCi | Keywords: newcomer Resolution: | Architecture: Unknown/Multiple Operating System: | Difficulty: Unknown Unknown/Multiple | Blocked By: Type of failure: | Related Tickets: None/Unknown | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Changes (by goldfire): * keywords: => newcomer Comment: Though I originally encountered my desire for this feature in a teaching setting, it happens in my own work, too. Say I have a big file with lots of definitions. Somewhere, there is a type error. To fix the type error, I need to check the types of other definitions in my file. But, I can't use GHCi to query my definitions, because the file has a type error. Urgh. So, today, I have to enable `-fdefer-type-errors`, load the file, see my type ''warnings'', and then query the definitions I need to fix everything up. A big annoyance of this workflow is that, now, `-fdefer-type-errors` is on and stays on until I reboot GHCi. None of this is the end of anybody's world, but I just think it would be easier for everyone -- particularly newcomers to Haskell -- if there were just a way to "force" loading, by enabling deferred type errors for one compilation. That's the proposal here. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8353#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#8353: Easy way to defer type errors -------------------------------------+------------------------------------- Reporter: goldfire | Owner: Type: feature | Status: new request | Milestone: Priority: normal | Version: 7.6.3 Component: GHCi | Keywords: newcomer Resolution: | Architecture: Unknown/Multiple Operating System: | Difficulty: Unknown Unknown/Multiple | Blocked By: Type of failure: | Related Tickets: None/Unknown | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Comment (by goldfire): Replying to [comment:3 simonpj]:

You can say `:set -fno-defer-type-errors`. You don't need to reboot GHCi, do you?

Oops. Of course. I still think this would be a nice feature. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8353#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#8353: Easy way to defer type errors -------------------------------------+------------------------------------- Reporter: goldfire | Owner: Type: feature request | Status: patch Priority: normal | Milestone: Component: GHCi | Version: 7.6.3 Resolution: | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: Type of failure: None/Unknown | Unknown/Multiple Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: Phab:D960 -------------------------------------+------------------------------------- Changes (by thomie): * cc: bgamari (added) Comment: Moving design discussion to Trac, so it gets some more attention. bgamari asks in Phab:D960:

Is there consensus that we want to expand the use of the ! suffix on GHCi commands? It seems to me like we might want to consider a slightly less cryptic (albeit more verbose) flag structure to expose this sort of functionality.

Currently we have: {{{ :ctags[!] [<file>] create tags file for Vi (default: "tags") (!: use regex instead of line number) :info[!] [<name> ...] display information about the given names (!: do not filter instances) :kind[!] <type> show the kind of <type> (!: also print the normalised type) }}} The patch in D960 adds: {{{ :load[!] [*]<module> ... load module(s) and their dependents (!: defer type errors) :reload[!] reload the current module set (!: defer type errors) }}} Seems all rather inconsistent, but not a huge problem either. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8353#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#8353: Easy way to defer type errors -------------------------------------+------------------------------------- Reporter: goldfire | Owner: Type: feature request | Status: patch Priority: normal | Milestone: Component: GHCi | Version: 7.6.3 Resolution: | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: Type of failure: None/Unknown | Unknown/Multiple Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: Phab:D960 -------------------------------------+------------------------------------- Comment (by goldfire): For whatever it's worth, I haven't changed my mind about wanting this feature, nor the choice of concrete syntax. Thanks for putting together a patch! -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8353#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#8353: Easy way to defer type errors -------------------------------------+------------------------------------- Reporter: goldfire | Owner: Type: feature request | Status: closed Priority: normal | Milestone: 7.12.1 Component: GHCi | Version: 7.6.3 Resolution: fixed | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: Type of failure: None/Unknown | Unknown/Multiple Blocked By: | Test Case: Related Tickets: | ghci/scripts/T8353 | Blocking: | Differential Revisions: Phab:D960 -------------------------------------+------------------------------------- Changes (by thomie): * status: patch => closed * testcase: => ghci/scripts/T8353 * resolution: => fixed * milestone: => 7.12.1 Comment: Thanks Benjamin. Hope to see you tackle another ticket soon. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8353#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler