How to hack -- that is, run from a fork rather than Cabal?

Questions and Answers
1

In a nutshell

I found instructions for installing and using Tidal -- and they worked! -- but I've found no guidance for hacking it.

More detail

Tidal's installation instructions explain how to install Tidal via Cabal. I did that. As a result, my ~/.cabal store now has a copy of Tidal, which defines how it works whenever I run Tidal.

I don't just want to use Tidal. I want to change how it works -- but hacking the Cabal store is a bad idea. So instead I'd like to use my own fork of the Tidal repo, outside of the Cabal store. I know how to clone and alter the Tidal repo, but I don't know how to use the result -- every time I start Tidal it runs from the Cabal store.

What I tried

The bottom of the docs for using Tidal on Emacs mentions that one might need to replace tidal-boot-script-path "with the actual location of the BootTidal.hs file". Following that advice, I tried adding this line to my .emacs config:

(setq tidal-boot-script-path "~/code/music/Tidal/Tidal/BootTidal.hs")

To test whether that had worked, I added to "~/code/music/Tidal/Tidal/src/Sound/Tidal/Core.hs" a synonym for silence called turpa. When I reboot Emacs and restart Tidal, :i silence is defined but :i turpa is not. So that didn't work.

Next I tried simply replacing the complicated definition of tidal-boot-script-path in tidal.el with this:

(defvar tidal-boot-script-path
  "~/code/music/Tidal/Tidal/BootTidal.hs")

I repeated the turpa = silence test described above. Still not working.

I don't have any more ideas.

2

Here's what I do..

Start from a clean slate by deleting ~/.ghc and ~/.cabal

Change into the tidal folder cd ~/code/music/Tidal

Install it using the 'old-style' cabal commands:

cabal v1-update
cabal v1-install

Then it should work from ghci (or via the edit plugins which generally use ghci).

This probably isn't 'best practice' use of the new v2-install commands, but as far as I can tell they are not designed for live coding and (therefore?) break all the time. Would love to hear different!

3

Weird. What version of Cabal do you use? Mine, 3.6.2.0, does not provide cabal v1-update. I do have v1-install. When I tried doing what you said, but using cabal update instead of cabal v1-update, it didn't work -- it still put tidal into my new .cabal folder, and my mod still wasn't recognized.

OTOH I can run cabal repl from the root of the project, run :s BootTidal.hs from the repl, and then use Tidal from that repl. That's good enough that I might not try to improve it for a while.

4

I got it working! No need for v1 commands or a global install.

From bash, I wiped my .ghc and .cabal folders like you suggested.

Then, in Emacs, I didn't use tidal.el at all. Instead I opened a shell (M-x shell),navigated to the root of the project, and typed cabal repl.

Then I defined these functions:

;; source:
;; https://emacs.stackexchange.com/a/37889
(defun my-set-target ()
   (interactive)
   (setq my-target (buffer-name)))

(defun my-send (beg end)
  (interactive "r")
  (process-send-region my-target beg end)
  (process-send-string my-target "\n"))

and ran my-set-target from the shell in Emacs.

Once that's done, I can highlight text in any buffer (doesn't have to end in .tidal) and send it to the shell buffer with my-set-target.

5

Another advantage of doing it that way: Tab completion.