From luke-tierney @ending from uiow@@edu  Fri Nov 16 15:34:55 2018
From: luke-tierney @ending from uiow@@edu (Tierney, Luke)
Date: Fri, 16 Nov 2018 14:34:55 +0000
Subject: [Rd] STRING_IS_SORTED claims as.character(1:100) is sorted
In-Reply-To: <CAHPe-e_81PU8SyN9VNAimsC-PuWx3VYoVrKAyivg_bHe8cLbeg@mail.gmail.com>
References: <CAHPe-e_81PU8SyN9VNAimsC-PuWx3VYoVrKAyivg_bHe8cLbeg@mail.gmail.com>
Message-ID: <alpine.DEB.2.21.1811160833140.3050@luke-Latitude-7480>

Thanks. Fixed in R_devel and R-patched. [STRING_IS_SORTED was not yet
used anywhere so this did not affect any computations.]

Best,

luke

On Thu, 15 Nov 2018, Michael Sannella via R-devel wrote:

> If I have loaded the C code:
>    SEXP altrep_STRING_IS_SORTED(SEXP x)
>    {
>        return ScalarInteger(STRING_IS_SORTED(x));
>    }
> and defined the function:
>    issort <- function(x) .Call("altrep_STRING_IS_SORTED",x)
>
> I am seeing the following results in R 3.5.1/Linux:
>    > issort(LETTERS)
>    [1] NA
>    > issort(as.character(1:100))  ## should return NA
>    [1] 1
>    > issort(as.character(100:1))  ## should return NA
>    [1] -1
>    > issort(as.character(1:100+1L))
>    [1] NA
>
> issort(as.character(1:100)) should return NA, since the string vector
> "1","2",..."10",... is not sorted.  I suspect that the problem is that
> the Is_sorted method for deferred_string is just calling the Is_sorted
> method for the source object 1:100 (which _is_ a sorted integer
> vector).  It should probably just return NA for any source object.
>
>  ~~ Michael Sannella
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>

-- 
Luke Tierney
Ralph E. Wareham Professor of Mathematical Sciences
University of Iowa                  Phone:             319-335-3386
Department of Statistics and        Fax:               319-335-3017
    Actuarial Science
241 Schaeffer Hall                  email:   luke-tierney at uiowa.edu
Iowa City, IA 52242                 WWW:  http://www.stat.uiowa.edu



[Rd] STRING_IS_SORTED claims as.character(1:100) is sorted
Tierney, Luke