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Re: vm branch now uses vm repl by default
From: |
Ludovic Courtès |
Subject: |
Re: vm branch now uses vm repl by default |
Date: |
Tue, 09 Sep 2008 10:41:41 +0200 |
User-agent: |
Gnus/5.11 (Gnus v5.11) Emacs/22.3 (gnu/linux) |
Hey!
Andy Wingo <address@hidden> writes:
> I've enabled the VM repl by default on the vm branch. Here's a brief
> annotated tour:
>
> $ ./pre-inst-guile
> Guile Scheme interpreter 0.5 on Guile 1.9.0
> Copyright (C) 2001-2008 Free Software Foundation, Inc.
>
> Enter `,help' for help.
Cool!
> Late-variable-ref looks at a cell in the object vector. If it is a
> symbol, it is resolved relative to the module that was current when the
> program was made. The object cell is then replaced with the resulting
> resolved variable. Here we see that objects 0 and 1 were already
> resolved. Object 2 is just the constant, #:bar.
Aaah, nice! So, previously, there was `variable-ref':
-- Instruction: variable-ref
Dereference the variable object which is on top of the stack and
replace it by the value of the variable it represents.
Now, there's also a vector associated with each closure to store
references to global variables, right? Looks better!
(Hint: the doc is outdated. :-))
> scheme@(guile-user)> ,option interp #t
> scheme@(guile-user)> ,option
> trace #f
> interp #t
>
> Here we tell the repl that, given the option, we prefer to interpret
> rather than compile. Of course, if the current language doesn't support
> compilation, we always interpret.
That means good old `CEVAL ()' is used, right?
When that is the case, one can still use `{eval,debug}-options', right?
It'd be nice if we could find a way to "do something" with the
`current-reader' fluid at compilation time, like detecting top-level
`(fluid-set! current-reader ...)' statements and use that to switch the
compiler's reader (hacky...).
Thanks for the good news!
Ludo'.