* Re: [9fans] Inferno, Limbo unexpectancies
@ 2002-02-15 12:52 Bengt Kleberg
0 siblings, 0 replies; 6+ messages in thread
From: Bengt Kleberg @ 2002-02-15 12:52 UTC (permalink / raw)
To: 9fans
> From: forsyth@caldo.demon.co.uk
> To: 9fans@cse.psu.edu
> Subject: Re: [9fans] Inferno, Limbo unexpectancies
>
> >>With the Inferno mail list down I hope to reach 'the right people' here at
> >>9fans.
>
> i'm not sure what happened to it; at first it looked as though pip had
> gone on holiday and could mend it when he got back
That is what he said/wrote.
> but i think we'll set
> up yet another one ourselves.
Mail lists need 'Atleast one' semantics :-)
bengt
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [9fans] Inferno, Limbo unexpectancies
@ 2002-02-14 15:43 forsyth
2002-02-15 0:48 ` Sam Ducksworth
0 siblings, 1 reply; 6+ messages in thread
From: forsyth @ 2002-02-14 15:43 UTC (permalink / raw)
To: 9fans
>>With the Inferno mail list down I hope to reach 'the right people' here at
>>9fans.
i'm not sure what happened to it; at first it looked as though pip had
gone on holiday and could mend it when he got back but i think we'll set
up yet another one ourselves.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [9fans] Inferno, Limbo unexpectancies
@ 2002-02-14 15:40 forsyth
2002-02-18 10:13 ` Maarit Maliniemi
0 siblings, 1 reply; 6+ messages in thread
From: forsyth @ 2002-02-14 15:40 UTC (permalink / raw)
To: 9fans
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>>1 shadowing
shad.b:12: warning: redeclaration of local n, previously declared as a local on line shad.b:10
request warnings and you'll get them (-w option to limbo)
>>2 no bounds check in JIT
there's a plan to make them available in JIT mode as well.
(at least optionally: there are some things that can be proved
correct and don't need them but could use the speed.)
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To: 9fans@cse.psu.edu
Subject: [9fans] Inferno, Limbo unexpectancies
Date: Thu, 14 Feb 2002 16:05:15 +0100 (MET)
Message-ID: <200202141505.g1EF5FP01844@cbe.ericsson.se>
With the Inferno mail list down I hope to reach 'the right people' here at
9fans.
If Inferno related emails are considered bandwith waisting, please let me know
and I will stop.
I have stumbled upon 2 things in Limbo that I would like to warn about
(presumably somebody else is as stupid as I am :-)
1 Unintended variable shadowing:
n := 3
while (n > 0) {
n:= n - 1; # i know of n--, but this is an example
}
as is obvious (afterwards), n will never reach 0.
i really think the compiler should warn about this.
2 No array bounds checking (only for JIT):
The below program will crash at the return statement in crash(), not in the
for() loop. Moreover, this only happens when using JIT.
bengt
implement Crash;
include "draw.m";
include "sys.m";
sys: Sys;
Crash: module {
init: fn(nil: ref Draw->Context, args: list of string);
};
init(nil: ref Draw->Context, args: list of string) {
sys = load Sys Sys->PATH;
a:= crash( );
return;
}
crash( ): array of byte {
result:= array [1] of byte;
for (i:= 0; i < 10; i++) {
sys->print( "%d\n", i );
result[i] = byte 0;
sys->print( "%d\n", len result );
}
return result[:5];
}
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [9fans] Inferno, Limbo unexpectancies
2002-02-14 15:40 forsyth
@ 2002-02-18 10:13 ` Maarit Maliniemi
0 siblings, 0 replies; 6+ messages in thread
From: Maarit Maliniemi @ 2002-02-18 10:13 UTC (permalink / raw)
To: 9fans
In article <20020214153452.6CD4D199BB@mail.cse.psu.edu>, 9fans@cse.psu.edu
wrote:
> >>1 shadowing
>
> shad.b:12: warning: redeclaration of local n, previously declared as a
local on line shad.b:10
>
> request warnings and you'll get them (-w option to limbo)
>
Would it not be better with the opposite behaviour?
Ie, if somebody knows about limbo they can turn off warnings they do not need.
Whereas the not-so-knowledgable (eg they do not even know that there are
warnings available) get them since they presumably need them a lot more...
bengt
^ permalink raw reply [flat|nested] 6+ messages in thread
* [9fans] Inferno, Limbo unexpectancies
@ 2002-02-14 15:05 Bengt Kleberg
0 siblings, 0 replies; 6+ messages in thread
From: Bengt Kleberg @ 2002-02-14 15:05 UTC (permalink / raw)
To: 9fans
With the Inferno mail list down I hope to reach 'the right people' here at
9fans.
If Inferno related emails are considered bandwith waisting, please let me know
and I will stop.
I have stumbled upon 2 things in Limbo that I would like to warn about
(presumably somebody else is as stupid as I am :-)
1 Unintended variable shadowing:
n := 3
while (n > 0) {
n:= n - 1; # i know of n--, but this is an example
}
as is obvious (afterwards), n will never reach 0.
i really think the compiler should warn about this.
2 No array bounds checking (only for JIT):
The below program will crash at the return statement in crash(), not in the
for() loop. Moreover, this only happens when using JIT.
bengt
implement Crash;
include "draw.m";
include "sys.m";
sys: Sys;
Crash: module {
init: fn(nil: ref Draw->Context, args: list of string);
};
init(nil: ref Draw->Context, args: list of string) {
sys = load Sys Sys->PATH;
a:= crash( );
return;
}
crash( ): array of byte {
result:= array [1] of byte;
for (i:= 0; i < 10; i++) {
sys->print( "%d\n", i );
result[i] = byte 0;
sys->print( "%d\n", len result );
}
return result[:5];
}
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2002-02-18 10:13 UTC | newest]
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2002-02-15 12:52 [9fans] Inferno, Limbo unexpectancies Bengt Kleberg
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2002-02-14 15:43 forsyth
2002-02-15 0:48 ` Sam Ducksworth
2002-02-14 15:40 forsyth
2002-02-18 10:13 ` Maarit Maliniemi
2002-02-14 15:05 Bengt Kleberg
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