Here is a very useful bash script to have lying around: #!/usr/bin/env bash shopt -s nullglob while true; do if [[ "$PWD" == "$HOME" || "$PWD" == / || -f "$PWD/package.yaml" || -f "$PWD/stack.yaml" || -n "$(echo -n ./*.cabal)" ]]; then exec "$@" else cd .. fi done Name this something like "run-in-project-root", and then you can prefix any command you run with "run-in-project-root" in order for it to run in the project's root, as defined by the existence of a package.yaml or stack.yaml or *.cabal file. (Of course you can customize the exact condition to your tastes.) So running "run-in-project-root fast-tags filename" is exactly like running "fast-tags filename" except that fast-tags will execute in the project root. (And the same for all the other shell commands that you run.) Of course, this works both when running fast-tags (or any other command) directly in the shell, and when running a bash snippet in vim with :!, so long as the "run-in-project-root" script is in a directory that's in your $PATH. On Mon, Apr 1, 2019 at 5:56 PM Nathan Merkley wrote:

While there is probably a better way, my limited knowledge of vimscript had me write this and it works well enough

function! UpdateHaskellTags() if filereadable("tags") execute "silent !grep -v '" . bufname("%") . "' ./tags > __newtags" execute "silent !rm tags" execute "silent !mv __newtags tags" execute "silent !fast-tags " . bufname("%") endif endfunction

autocmd BufWritePost *.hs :call UpdateHaskellTags() autocmd BufWritePost *.hsc :call UpdateHaskellTags()

This uses fast-tags to regenerate tags for the current file on every save, but will only work if you are operating from the root of your project (or wherever you keep your tags). I use ctrlp for navigation so that's never been a problem for me

Nathan Merkley

On Mon, Apr 1, 2019 at 9:26 AM Vanessa McHale wrote:

...

Hi all,

I had been using hasktags for tag generation previously, however, I recently discovered that using GHCi with

cabal new-repl λ:> :ctags

creates a tags file that actually works with preprocessors (e.g. c2hs or alex or happy).

Is there any way to run this semi-automatically?

echo ':ctags' | cabal new-repl

seems to work in the shell, but I'd like a vim integration if possible (also, it's slow).

Cheers, Vanessa McHale

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Benjamin, Thanks for that, that should come in very handy Vanessa, While I haven't tried it, you should be able to replace fast-tags with any tool of your choice, as the script is just running a sequence of shell commands. The one caveat is that the script I sent generates tags on a per-file basis, so if generating them from the repl doesn't merge the tags file, you will have to change it to instead generate tags for the entire project directory Nathan Merkley On Mon, Apr 1, 2019, 12:10 PM Vanessa McHale wrote:

Unfortunately, fast-tags doesn't work with happy/alex/c2hs preprocessors :(

Cheers On 4/1/19 10:56 AM, Nathan Merkley wrote:

While there is probably a better way, my limited knowledge of vimscript had me write this and it works well enough

function! UpdateHaskellTags() if filereadable("tags") execute "silent !grep -v '" . bufname("%") . "' ./tags > __newtags" execute "silent !rm tags" execute "silent !mv __newtags tags" execute "silent !fast-tags " . bufname("%") endif endfunction

autocmd BufWritePost *.hs :call UpdateHaskellTags() autocmd BufWritePost *.hsc :call UpdateHaskellTags()

This uses fast-tags to regenerate tags for the current file on every save, but will only work if you are operating from the root of your project (or wherever you keep your tags). I use ctrlp for navigation so that's never been a problem for me

Nathan Merkley

On Mon, Apr 1, 2019 at 9:26 AM Vanessa McHale wrote:

...

Hi all,

I had been using hasktags for tag generation previously, however, I recently discovered that using GHCi with

cabal new-repl λ:> :ctags

creates a tags file that actually works with preprocessors (e.g. c2hs or alex or happy).

Is there any way to run this semi-automatically?

echo ':ctags' | cabal new-repl

seems to work in the shell, but I'd like a vim integration if possible (also, it's slow).

Cheers, Vanessa McHale

_______________________________________________ Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to: http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Only members subscribed via the mailman list are allowed to post.

_______________________________________________ Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to:http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Only members subscribed via the mailman list are allowed to post.

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On Mon, Apr 1, 2019 at 8:56 AM Nathan Merkley wrote:

While there is probably a better way, my limited knowledge of vimscript had me write this and it works well enough

function! UpdateHaskellTags() if filereadable("tags") execute "silent !grep -v '" . bufname("%") . "' ./tags > __newtags" execute "silent !rm tags" execute "silent !mv __newtags tags" execute "silent !fast-tags " . bufname("%") endif endfunction

autocmd BufWritePost *.hs :call UpdateHaskellTags() autocmd BufWritePost *.hsc :call UpdateHaskellTags()

If I'm reading it right, this goes to a lot of work to defeat (or reimplement?) the default incremental tagging. Why not just 'execute fast-tags %'? I use a script like "if [[ -r tags ]]; then fast-tags -R; else fast-tags $1; fi" for that first generate, and put 'rm tags' in the merge posthook.