Hans Aberg <haber...@telia.com> writes: > On 16 Dec 2011, at 11:33, Mark H Weaver wrote: > >> Here's what I currently see: >> >> scheme@(guile-user)> (local-eval #'t (primitive-eval '(let ((t 42)) >> (or #f (the-environment))))) >> ERROR: In procedure memoize-variable-access!: >> ERROR: Unbound variable: t >> >> This is the correct behavior, no? > > This is what I get when I play around with the following variation of David's > code in Guile 2.0.3: > (define (xxx) > (let* ((x 2)) > (set! x (+ x 3)) > (interaction-environment))) > > (eval '(begin (set! x (+ x 5)) x) (xxx)) > > My guess (correct?) is that one wants some variation of > (interaction-environment) that can cause x in the eval expression to > bind to the environment returned by (xxx). > > Might eval be changed to accommodate for that (without introducing the > name local-eval)?
It would likely help with unasking the question of what to do when (current-module) is different at the time of local-eval. I don't know, however, what the _lexical_ effects of switching the current module are supposed to be. If it is supposed to be a noop, then lexical environments and modules are presumably orthogonal, and eval should likely be allowed to take both (currently, local-eval is like taking a lexical environment and using primitive-eval in it). -- David Kastrup