Add global access to all available REPLs

[AlejandroCatalina]

Enable a global binding to access a list of available REPLs to run everywhere. If the requested REPL depends on a major-mode that hasn't been loaded, it will be loaded along its dependencies. The global binding is under SPC a R.

To make this work, a new spacemacs/register-repl function is included. This function adds a major-mode and its repl function to a global variable.

Further work, such as add every layer REPL to this list is due to be completed after this PR is eviewed, to avoid silly work.

Address #3395

[syl20bnr]

Remove the mention to the key binding.

"List of all registered REPLs" is sufficient

[AlejandroCatalina]

Right, done.

[AlejandroCatalina]

What about SPC a C-r. If I didn't misunderstood, the key-binding order was from minus-mayus-Control-Control Shift.

[StreakyCobra]

What about SPC up up down down left right left right B A 😉

More seriously:

SPC a i r for application i nteractive repl
SPC a i prefix can be set to "irc/interactive"

but we need the opinion of other people anyway I think.

[AlejandroCatalina]

That sounds good and mnemonic. Let some other people show their opinion :P.

Btw, how to set a prefix binding?

[StreakyCobra]

spacemacs/layers/+distribution/spacemacs-base/config.el

Lines 17 to 68 in 8adb066

	(setq spacemacs/key-binding-prefixes '(("a" "applications")
	("ai" "irc")
	("as" "shells")
	("b" "buffers")
	("bm" "move")
	("c" "compile/comments")
	("C" "capture/colors")
	("e" "errors")
	("f" "files")
	("fC" "files/convert")
	("fe" "emacs(spacemacs)")
	("fv" "variables")
	("g" "git/versions-control")
	("h" "help")
	("hd" "help-describe")
	("i" "insertion")
	("j" "jump/join/split")
	("k" "lisp")
	("kd" "delete")
	("kD" "delete-backward")
	("k`" "hybrid")
	("n" "narrow/numbers")
	("p" "projects")
	("p$" "projects/shell")
	("q" "quit")
	("r" "registers/rings/resume")
	("Re" "elisp")
	("Rp" "pcre")
	("s" "search/symbol")
	("sa" "ag")
	("sg" "grep")
	("sk" "ack")
	("st" "pt")
	("sw" "web")
	("t" "toggles")
	("tC" "colors")
	("tE" "editing-styles")
	("th" "highlight")
	("tm" "modeline")
	("T" "UI toggles/themes")
	("C-t" "other toggles")
	("w" "windows")
	("wp" "popup")
	("x" "text")
	("xa" "align")
	("xd" "delete")
	("xg" "google-translate")
	("xl" "lines")
	("xm" "move")
	("xt" "transpose")
	("xw" "words")
	("z" "zoom")))

[StreakyCobra]

or (spacemacs/declare-prefix "oi" "insert")

[AlejandroCatalina]

I see, when other people show themselves we'll add it. So far, SPC a i r looks right to me.

[jmiven]

SPC a i r is also already occupied by rcirc! 😉
https://github.com/syl20bnr/spacemacs/blob/develop/layers/+irc/rcirc/packages.el#L68

[AlejandroCatalina]

Oh god, SPC a i R seems to be free, anyone who breaks that one too? 😂

[StreakyCobra]

SPC a i r is also already occupied by rcirc!

Oh, I shouldn't have been on the correct project when I searched for it 😔

[AlejandroCatalina]

Are we okay with SPC a i R?

[syl20bnr]

I have to think about it, SPC a i R looks fine for a first binding.

[AlejandroCatalina]

I'll add it tomorrow then ;).

[AlejandroCatalina]

If this is okay as it is, i'll rebase it.

[AlejandroCatalina]

Everything rebased and ready to go!

[TheBB]

Thanks! Cherry-picked in develop. You can safely delete your branch.

I cleaned your code up a bit in e8a10c3. In particular, calling a major mode function is a poor way of loading a file, just call require instead. I also used call-interactively instead of funcall.

In bedf807 I fixed the ielm code (which wasn't up to scratch) and registered it as a REPL, and I also did the shells in 44fd52d.

That's a good start.

[TheBB]

Oh, and I changed the binding to SPC a '. :-)