Proposal to not `quit` when we are working inside Slime

[vindarel]

Hello there,

I tried defmain, and I tried to call the main function from Emacs & Slime. It should be possible, since what defmain does is creating a defun called main which accepts a &rest argv. My goal was to call the main function from a run.lisp script. That way I could avoid writing another function that would be called by main and that would accept the same key arguments from main.

So I evaluated (C-x C-e) or compiled a line like (mypackage::main :debug t) to see what it does, but it closes the Lisp connection.

I suggest we check if we are on Slime and do not quit in that case. A very simple way is to check the TERM environment variable. On Slime, it's "dumb". I made a trivial system for that: termp.

[svetlyak40wt]

This is a good idea. Ideally, we should call this helper system like in-ide instead of termp, because there are other environments like SLY, Lem, Closure IDE, LispWorks, etc. I'd create a single function there which will return a keyword for IDE kind or NIL, if this script is running standalone.

[svetlyak40wt]

By the way, a function defined with defmain will not work like this (mypackage::main :debug t), because it defines a function which accepts args which are unix args – a list of strings.

To solve this issue really well, we need to separate defined body where variables names a used as keywords from the function which parses command-line arguments. And a version to be called should be chosen depending on IDE or non-IDE environent.

[vindarel]

How would you find the IDE kind? (is there an environment variable for this?)

[svetlyak40wt]

I don't see any special environment variables in LispWorks listener. But probably the best way will be to figure out IDE from backtrace stack frames.

For example, in lispworks it contains a call to INTERACTIVE-PANE-TOP-LOOP:

CL-USER 33 > (dbg:output-backtrace :bried)
Call to EVAL
Call to CAPI::CAPI-TOP-LEVEL-FUNCTION
Call to CAPI::INTERACTIVE-PANE-TOP-LOOP
Call to MP::PROCESS-SG-FUNCTION

In SBCL running under the SLYNK:

...
/Users/art/projects/lisp/sly/slynk/slynk.lisp:tlf73fn4: CALL-WITH-LISTENER:
 FN = #<FUNCTION (LAMBDA () :IN SLYNK::SPAWN-CHANNEL-THREAD) {1003B4802B}>
 LISTENER = #<SLYNK-MREPL::MREPL mrepl-1-1>
 OBJECT = #<SLYNK-MREPL::MREPL mrepl-1-1>
 SAVING = NIL
/Users/art/projects/lisp/sly/slynk/slynk.lisp:tlf131fn4: (FLET FORM-FUN-5 IN SPAWN-CHANNEL-THREAD):
 CONNECTION = #<SLYNK::MULTITHREADED-CONNECTION {10027A5C93}>
 G6 = #<SLYNK-MREPL::MREPL mrepl-1-1>
...

[svetlyak40wt]

The guesser should search for packages such as CAPI, SLYNK, SWANK, etc and then check if some symbols are present in the stackframes.

[vindarel]

mmh good ideas, though would you maybe accept a first patch that does like termp? "make it work, make it right"…