supporting dynamic/interactive procedure re-definition

[Per Bothner <per at bothner dot com>]

On 08/21/2010 02:51 PM, Helmut Eller wrote:
> For me, interactive programming includes that it's possible to compile a
> file and load the compiled code into the running Lisp.  I want to use
> the same file, with the same module imports/exports as I would for a
> batch compiler.  Then I want to make a small fix to the file, compile it
> and load it again.  And the (existing) bindings should be updated in
> some sensible way.  Yes, updatable bindings are obviously a problem for
> compile-time analysis.

I checked in an experimental fix that should help.

For example, create a file /tmp/foo.scm, containing:

(define (foo) "old")

$ kawa
#|kawa:1|# (require "/tmp/foo.scm")
#|kawa:2|# (define (bar) (foo))
#|kawa:3|# (define baz (list foo))
#|kawa:4|# (bar)
old
#|kawa:5|# ((car baz))
old

Then edit /tmp/foo.scm to:

(define (foo) "new")

and then:

##|kawa:6|# (require "/tmp/foo.scm")
#|kawa:7|# (bar)
new
#|kawa:8|# ((car baz))
new

Note this only handles functions, not variables, and specifically
only functions defined using this form:

(define (NAME PARAMS) BODY)

There are probably other limitations (and bugs); please let me know.
--
	--Per Bothner
per@bothner.com   http://per.bothner.com/