Initializing MEDLEY-INIT-VARS

[rmkaplan]

i don't think there would be a problem with using ADDVARS ... this all was done when the loadup process was not scripted. The difficulties come when cross-compiling for a different maiko/opcodes where you don't want to mix the directories for things to run in this environment vs things to run in the future -- if they are being set in an ADDVARS when you're adding future values to the current values?

Originally posted by @masinter in #2358 (comment)

[rmkaplan]

Actually, there does appear to be a problem with ADDVARS, although I'm grasping to understand what's going on.

One of the early things that the MAKEINIT does is to load MEDLEYDIR and then evaluate (MEDLEY-INIT-VARS). With the ADDVARS for the values of MEDLEY-INIT-VARS you get the stuff you want but you also have the stuff that previously existed in the starter Lisp sysout, and some of those might not make sense (and error).

But there is a problem with the current VARS also. Whenever the file MEDLEYDIR is worked on and dumped, for whatever reason, the value of MEDLEY-INIT-VARS in that memory image is copied back into the MEDLEYDIR file. So for example, UNIXUTILS ADDVARS (ShellBrowser)(ShellOpener) when it is loaded, but those entries already migrated to MEDLEYDIR when it was last dumped. Those will live on even if the Unix tools are changed sometime in the future--they have been detached from their logical source, a breakdown of modularity.

Similarly, the entries to erase the font-exists and fonts-available caches logically belong in FONT--maybe someone wil decide to change that interface--but adding the entries there would only have an effect if I then wrote out MEDLEYDIR from a new loadup. That's because FONT is earlier in the loadup then the load of MEDLEYDIR that happens when the loadup-lisp phase starts.

If those are the issues, then one solution would be to have the MAKEINIT script set MEDLEY-INIT-VARS back to NOBIND just before it loads MEDLEYDIR, and then put an INITVARS command in MEDLEYDIR. That would guarantee that only the desired values are present at that point, wouldn't allow for the accidental accumulation of other entries, and would allow files to add (and own) their entries whether they come early or late in the loadup sequence.