Add recipe for ob-elm

[BonfaceKilz]

Brief summary of what the package does

Org-Babel support for evaluating Elm code

Direct link to the package repository

https://github.com/BonfaceKilz/ob-elm

Your association with the package

I'm the author

Relevant communications with the upstream package maintainer

None needed

Checklist

Please confirm with x:

• The package is released under a GPL-Compatible Free Software License.
• I've read CONTRIBUTING.org
• I've used the latest version of package-lint to check for packaging issues, and addressed its feedback
• My elisp byte-compiles cleanly
• M-x checkdoc is happy with my docstrings
• I've built and installed the package using the instructions in CONTRIBUTING.org
• I have confirmed some of these without doing them

Note:

• When using package-lint, I found:

6 issues found:

6:3: warning: You should include standard keywords: see the variable `finder-known-keywords'.
51:0: error: "org-babel-elm-eoe" doesn't start with package's prefix "ob-elm".
105:0: error: "org-babel-elm-initiate-session" doesn't start with package's prefix "ob-elm".
112:0: error: "org-babel-load-session:elm" doesn't start with package's prefix "ob-elm".
112:0: error: `org-babel-load-session:elm' contains a non-standard separator `:', use hyphens instead (see Elisp Coding Conventions).
134:0: error: "org-babel-elm-var-to-elm" doesn't start with package's prefix "ob-elm".

I ignored the above errors because fixing them would mean going against conventions set here in the officicial org template for extending languages

[riscy]

Thanks, looks useful.

ob-elm.el

M-x checkdoc (using version 0.6.1):
No issues! 💯

M-x package-lint-current-buffer (using version 20191124.132):

6 issues found:

6:3: warning: You should include standard keywords: see the variable `finder-known-keywords'.
<snip>

The org-babel conventions seem fine, but the above one could be addressed.

M-x byte-compile-file (using Emacs 26.3):
Per CONTRIBUTING.org, consider using lexical binding
(the following is with lexical binding enabled)

ob-elm.el:64:29:Warning: `assq' called with 8 args, but requires 2
ob-elm.el:81:36:Warning: assq called with 8 arguments, but accepts only 2
ob-elm.el:64:47:Warning: reference to free variable `pThe'
ob-elm.el:64:52:Warning: reference to free variable `header-args'
ob-elm.el:64:64:Warning: reference to free variable `passed'
ob-elm.el:64:71:Warning: reference to free variable `to'
ob-elm.el:64:74:Warning: reference to free variable `the'
ob-elm.el:64:78:Warning: reference to free variable `src'
ob-elm.el:64:82:Warning: reference to free variable `block\.arams'

In end of data:
ob-elm.el:153:1:Warning: the following functions are not known to be defined:
    org-trim, org-strip-quotes

I think a typo snuck in for the first chunk. A (require 'org) is needed for org-trim, and I think org-strip-quotes isn't available with Emacs 26.3's version of org (I don't know about Emacs 27), so you should add a later-versioned Package-Require on org. Or you could use org-babel-strip-quotes for backward compatibility.

[BonfaceKilz]

@riscy Done. I've opted to specify the org version. Here's the merged(upstream) PR: https://github.com/BonfaceKilz/ob-elm/pull/9/files

Here are the specific commits that address each of the points addressed above:

• Fixing the typo: BonfaceKilz/ob-elm@36582a8
• Adding lexical binding: BonfaceKilz/ob-elm@432ea93
• Specifying the org version: BonfaceKilz/ob-elm@c73bacf
• Use standard key words: BonfaceKilz/ob-elm@37d791a

[riscy]

This is almost there, but I'm having trouble with this expression here (maybe you can clarify):

  (add-hook 'elm-mode-hook
            (lambda ()
              (setq-local comint-prompt-regexp
                          (concat elm-prompt-regexp "\\|^λ?> "))))

Does this have any effect? For instance I don't think elm-mode pays any attention to comint-prompt-regexp (but perhaps elm-repl does? Do we care it does for the purposes of this package?)

For reference, I see ob-haskell has something similar,

(add-hook 'inferior-haskell-hook
            (lambda ()
              (setq-local comint-prompt-regexp
                          (concat haskell-prompt-regexp "\\|^λ?> "))))

but the hook here is being added to inferior-haskell (i.e. the REPL) instead of haskell-mode.

Since I'm not too familiar with ob stuff, I'm not sure what the goal of changing the prompt is. But usually a change like that (one that a user might want to undo) should be done through a minor mode, not as a hook that gets snuck in when a function is called. In addition, anything you add as a hook in a package should probably be a named function, not an anonymous one -- named functions can be easily redefined, and named functions are easier to remove from hooks once they're in there.

That was a bit long-winded, but if that expression isn't having any effect, I wonder if you could just remove it?

[BonfaceKilz]

Thanks for the review. I've learnt something about things to watch out for when creating a package 😄 👍

I'm not an expert on ob myself... I really wanted to evaluate elm inside org so I hacked up something that works. With regards, to the minor hook, you are right... It has no effect on the elm buffer(and anyways I don't think it matters because the output in the org buffer is what matters). Anyways, I've removed it here

[riscy]

Great, thanks for this. And, welcome to MELPA!