Question - Using as.period within a package

[rsangole]

Hello,

Situation

I don't wish to write require(lubridate) in my package. However, not doing so results in an error.

Error & Reproducible Example

• Doesn't work:

In a brand new R session.

lubridate::as.period(x = 10, unit = 'day')
#> Error in get(as.character(FUN), mode = "function", envir = envir): object 'days' of mode 'function' was not found

• Works:

In a brand new R session.

library('lubridate')
#> 
#> Attaching package: 'lubridate'
#> The following object is masked from 'package:base':
#> 
#>     date
lubridate::as.period(x = 10, unit = 'day')
#> [1] "10d 0H 0M 0S"

Why is this behavior true?

Background

I'm writing a package which uses the lubridate::as.period function and would like to make a call like:

historic_timeperiod <- lubridate::as.period(30, units='days')

(In the package, lubridate is set as Imports:)

Version Information

R version 3.3.3 (2017-03-06)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Ubuntu 16.04.4 LTS

locale:
[1] LC_CTYPE=en_US.UTF-8 LC_NUMERIC=C LC_TIME=en_US.UTF-8 LC_COLLATE=en_US.UTF-8
[5] LC_MONETARY=en_US.UTF-8 LC_MESSAGES=en_US.UTF-8 LC_PAPER=en_US.UTF-8 LC_NAME=C
[9] LC_ADDRESS=C LC_TELEPHONE=C LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C

attached base packages:
[1] stats graphics grDevices utils datasets methods base

other attached packages:
[1] RevoUtilsMath_10.0.0 RevoUtils_10.0.3 RevoMods_11.0.0 MicrosoftML_1.3.0 RevoScaleR_9.1.1
[6] lattice_0.20-34 rpart_4.1-10

loaded via a namespace (and not attached):
[1] codetools_0.2-15 lubridate_1.6.0 CompatibilityAPI_1.1.0 foreach_1.4.3 grid_3.3.3
[6] R6_2.2.0 jsonlite_1.3 magrittr_1.5 stringi_1.1.2 iterators_1.0.8
[11] tools_3.3.3 stringr_1.2.0 mrupdate_1.0.1

[vspinu]

It should work without attaching the package.

## in  a new session on a similar platform as yours
> lubridate::as.period(x = 10, unit = 'day')
[1] "10d 0H 0M 0S"

Might be an instalation issue. Please try to reinstall lubridate. If you use lubridate as imports you can also specify which functions you would like to use and use them without lubridate:: prefix. Shouldn't matter though.

#' @importFrom lubridate as.period

or in NAMESPACE

importFrom(lubridate,as.period)

[rsangole]

Odd. It might be an installation issue.

On the + side, lubridate::period() works perfectly and I'm going to run with that for now. I'm OK closing this issue.

[vspinu]

Actually I can reproduce. It's because of the match.fun within as.period. It looks like that function has a non dynamic lookup which is rather unexpected. Give me a sec.

[vspinu]

Actually it has a dynamic lookup which was the cause of the problem. Thanks for reporting this!

[rsangole]

Wow, super quick!! Thanks @vspinu !