Hi,
In R 3.4.0, the "Pattern Matching and Replacement" documentation that
describes regexec(), gregexpr(), etc. states that the "text" argument
to regexec is a character vector, "or an object which can be coerced by
as.character to a character vector":
regexec(pattern, text, ignore.case = FALSE, perl = FALSE,
fixed = FALSE, useBytes = FALSE)
x, text: a character vector where matches are sought, or an object
which can be coerced by as.character to a character vector.
Long vectors are supported.
However, in R 3.4.0, this coercion doesn't seem to automatically occur for
the text argument of regexec(), whereas it does for gregexpr(), regexpr(), etc:
===========================================================$ R --vanilla
R version 3.4.0 (2017-04-21) -- "You Stupid Darkness"
Copyright (C) 2017 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)
...> text <- as.factor("foobar")
> regexec("foo", text)
Error in regexec("foo", text) : invalid 'text'
argument> regexec("foo", as.character(text))
[[1]]
[1] 1
attr(,"match.length")
[1] 3
attr(,"useBytes")
[1] TRUE
> gregexpr("foo", text)
[[1]]
[1] 1
attr(,"match.length")
[1] 3
attr(,"useBytes")
[1] TRUE
===========================================================
Is this a documentation issue, a bug in regexec(), or am I misunderstanding how
it's supposed to behave?
Thanks,
--
Nathan Weeks
IT Specialist
USDA-ARS Corn Insects and Crop Genetics Research Unit
Crop Genome Informatics Laboratory
Iowa State University
This electronic message contains information generated by the USDA solely for
the intended recipients. Any unauthorized interception of this message or the
use or disclosure of the information it contains may violate the law and subject
the violator to civil or criminal penalties. If you believe you have received
this message in error, please notify the sender and delete the email
immediately.