use-modules in gexps

[Ricardo Wurmus]

Hi Guix,

I just watched the excellent FOSDEM talk about G-expressions by Chris
Marusich.  One person asked at the end about why it is necessary to use
“with-imported-modules” when inside of the G-expression “use-modules” is
used.

I wondered if perhaps we could add a G-expression compiler for module
imports, so that instead of

(with-imported-modules (source-module-closure '((my module)))
  #~(begin
     (use-modules (my module))
     …))

we would do

  #~(begin
     #$(use-modules (my module))
     …)

which would have the effect of adding (my module) — or the module
closure – to the list of modules needed by the current G-expression.

Can a G-expression compiler help accumulate state (e.g. by making
G-expressions values in the state monad) or can it only be compiled down
to a value at the current location?

--
Ricardo