Hi Andy,
Thanks for the explanations.
On mar., 30 avril 2024 at 16:43, Andy Wingo <wi...@igalia.com> wrote:
>> The first question is: is it still correct? Because this module had
>> been implemented before many Guile compiler improvements.
>
> No, the comment is incorrect. The type check on whatever accessor is
> called first (unspecified in scheme; probably we should just bite the
> bullet and do predictable left-to-right semantics, as racket does) will
> dominate the rest and eliminate those checks. The assert-type is
> unnecessary.
Good to know.
> To see this, do ,optimize-cps at the repl, and count the number of
> e.g. struct? checks with and without the assert-vlist. There is only
> one, either way.
Hum, I am not sure to understand how to use ,optimize-cps at the repl.
Naively, I get:
--8<---------------cut here---------------start------------->8---
scheme@(guile-user)> ,use(ice-9 vlist)
scheme@(guile-user)> ,optimize-cps (vlist-cons 'foo vlist-null)
L0: ; at <unknown>:102:14
v0 := self
L1(...)
L1:
receive()
v1 := current-module() ; mod While executing
meta-command:
In procedure +: Wrong type argument in position 1: #f
--8<---------------cut here---------------end--------------->8---
Since ’,help compile’ reads,
,optimize-cps EXP [,optx] - Run the CPS optimizer on a piece of
code and print the result.
I assume that I do not feed with the correct expression EXP. What would
be the invocation?
> (A type check is a heap-object? check, then struct?,
> then get the vtable, then check against the global variable <vlist>.
> All of these duplicates get eliminated.)
Ah yeah, it makes sense. :-)
Cheers,
simon
