* bug#20375: doc. error in v 2.0.11, Section 7.6.2.5
@ 2015-04-20 2:20 Matt Wette
2016-06-23 20:07 ` Andy Wingo
0 siblings, 1 reply; 2+ messages in thread
From: Matt Wette @ 2015-04-20 2:20 UTC (permalink / raw)
To: 20375; +Cc: mwette
The reference manual for guile 2.0.11 has an error in Section 7.6.2.5 on rnrs lists. The statement "identical to the fold ..." is not quite correct. The section says:
fold-left combine nil list1 list2 . . . [Scheme Procedure] fold-right combine nil list1 list2 . . . [Scheme Procedure] These procedures are identical to the fold and fold-right procedures provided by SRFI-1. See Section 7.5.3.5 [SRFI-1 Fold and Map], page 556, for documentation.
In section 7.5.3.5, the manual says:
(fold cons ’() ’(1 2 3)) [...] (3 2 1)
But, fold-left does not work like fold: the arguments to the procedure to fold-left are reversed with respect to fold:.
guile i2.0.11correctly gives the following:
(fold-left cons '() '(1 2 3)) => (((() . 1) . 2) . 3)
(fold-left xcons '() '(1 2 3)) => (3 2 1)
Matt
^ permalink raw reply [flat|nested] 2+ messages in thread
* bug#20375: doc. error in v 2.0.11, Section 7.6.2.5
2015-04-20 2:20 bug#20375: doc. error in v 2.0.11, Section 7.6.2.5 Matt Wette
@ 2016-06-23 20:07 ` Andy Wingo
0 siblings, 0 replies; 2+ messages in thread
From: Andy Wingo @ 2016-06-23 20:07 UTC (permalink / raw)
To: Matt Wette; +Cc: 20375-done
On Mon 20 Apr 2015 04:20, Matt Wette <mwette@alumni.caltech.edu> writes:
> The reference manual for guile 2.0.11 has an error in Section 7.6.2.5
> on rnrs lists. The statement "identical to the fold ..." is not quite
> correct. The section says:
>
> fold-left combine nil list1 list2 . . . [Scheme Procedure] fold-right
> combine nil list1 list2 . . . [Scheme Procedure] These procedures are
> identical to the fold and fold-right procedures provided by
> SRFI-1. See Section 7.5.3.5 [SRFI-1 Fold and Map], page 556, for
> documentation.
>
>
> In section 7.5.3.5, the manual says:
> (fold cons ’() ’(1 2 3)) [...] (3 2 1)
>
>
> But, fold-left does not work like fold: the arguments to the procedure to fold-left are reversed with respect to fold:.
>
> guile i2.0.11correctly gives the following:
>
> (fold-left cons '() '(1 2 3)) => (((() . 1) . 2) . 3)
>
> (fold-left xcons '() '(1 2 3)) => (3 2 1)
Gah, you're right. What a mess. Fixed in master, will backport
soonish.
Andy
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2016-06-23 20:07 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-04-20 2:20 bug#20375: doc. error in v 2.0.11, Section 7.6.2.5 Matt Wette
2016-06-23 20:07 ` Andy Wingo
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).