ghc-imported-from
For a given Haskell source file, determine the path to the Haddock documentation for a symbol at a particular line/col location.
Example: on the file src/Main.hs,
ghc-imported-from src/Main.hs Main strOption 18 17
says
SUCCESS: file:///home/carlo/.stack/snapshots/x86_64-linux/lts-5.8/7.10.3/doc/optparse-applicative-0.12.1.0/Options-Applicative-Builder.html
since the usage of strOption at line 18, column 17, is from the Options.Applicative.Builder module.
Difficulties arise in resolving names because some symbols are exported from a certain
package but defined in another, for example String is defined in
GHC.Base but is exported from the standard prelude, the module
Prelude. There are other cases to deal with including qualified
imports, selective imports, imports with hidden components, etc.
Using with Stack
Stack makes everything easier.
Build ghc-imported-from:
git clone https://github.com/carlohamalainen/ghc-imported-from
cd ghc-imported-from
stack build
then add
`pwd`/.stack-work/install/x86_64-linux/lts-5.8/7.10.3/bin
or similar to your $PATH.
Then in a project that you are working on:
cd my-project
stack build
stack haddock # Must do this!
ghc-imported-from some/file/Blah.hs Blah f 100 3
Tests
Run the tests using Stack:
stack test
ghcimportedfrom-vim
For Vim users,
follow the instructions at
[https://github.com/carlohamalainen/ghcimportedfrom-vim](https://github.com/carlohamalainen/ghcimportedfrom-vim)
to install the Vim plugin.
ghc-imported-from-el
For Emacs users, David Christiansen has written ghc-imported-from-el.
Usage
See the tests subdirectory for some examples. Or load your favourite Haskell project and hit F4.
Or watch the screencast (be sure to set 720p HD and then fullscreen):
[https://www.youtube.com/watch?v=7yO_VGCWMu8](https://www.youtube.com/watch?v=7yO_VGCWMu8)
Notes
ghc-imported-from uses both GHC and ghc-pkg, which
accept arguments in differing formats. For example GHC takes
-package-db while ghc-pkg takes --package-db=. For more
details: http://www.vex.net/~trebla/haskell/sicp.xhtml
Debugging
To see the GHC options that have been automatically detected, change into your project's directory and run:
$ cd ~/ghc-imported-from
$ cabal repl --with-ghc=fake-ghc-for-ghc-imported-from
Preprocessing library ghc-imported-from-0.2.0.2...
--interactive -fbuilding-cabal-package -O0 -outputdir dist/build -odir dist/build -hidir dist/build -stubdir dist/build -i -idist/build -i. -idist/build/autogen -Idist/build/autogen -Idist/build -optP-include -optPdist/build/autogen/cabal_macros.h -package-name ghc-imported-from-0.2.0.2 -hide-all-packages -no-user-package-db -package-db /home/user/ghc-imported-from/.cabal-sandbox/x86_64-linux-ghc-7.6.3-packages.conf.d -package-db dist/package.conf.inplace -package-id Cabal-1.16.0-c6e09e008cd04cf255c1ce0c59aba905 -package-id base-4.6.0.1-8aa5d403c45ea59dcd2c39f123e27d57 -package-id containers-0.5.0.0-ab1dae9a94cd3cc84e7b2805636ebfa2 -package-id directory-1.2.0.1-91a788fd88acd7f149f0f10f5f1e23f2 -package-id filepath-1.3.0.1-b12cbe18566fe1532a1fda4c85e31cbe -package-id ghc-7.6.3-18957ddbb817289f604552aa2da2e879 -package-id ghc-mod-4.1.0-a87501f2667239b3f0bef3e0f3753496 -package-id ghc-paths-0.1.0.9-3817f31ae510ed3b58554933ea527b74 -package-id ghc-syb-utils-0.2.1.2-bf72c1e71339c52f0af404a12449c9d2 -package-id mtl-2.2.0.1-ef91e0abcf7a4fb581ecb7fe83cdcba1 -package-id process-1.1.0.2-76e05340eb66705981411022731ca84a -package-id safe-0.3.4-ba52ca348aecad429ba90450e3aba4c4 -package-id syb-0.4.1-9469ffdd9c6a7ebbf035421c915a08ee -package-id transformers-0.4.1.0-42810d723884ebf2a2dd638e5b22e523 -XHaskell2010 Language.Haskell.GhcImportedFrom Language.Haskell.GhcImportedFrom.UtilsFromGhcMod Language.Haskell.GhcImportedFrom.Types -Wall
Alternatives
As far as I know the only alternative is the fpco/hoogle-doc function in
[https://www.fpcomplete.com/page/api](https://www.fpcomplete.com/page/api). Or try Ctrl-i
in the web version of FP Complete.
