[R] Lexical scoping/calling stack issue: R fails to recognize an argument's default value

[Janko Thyson]

Thanks. I will try to further simplify the example.

On Sat, Nov 15, 2014 at 2:01 AM, Jeff Newmiller <jdnewmil at dcn.davis.ca.us>
wrote:

> While you appear to have been thorough in providing access to your code, I
> don't think I will install a bunch of your dev code to debug it for you.
> The Posting Guide does say your example should be minimal, and IMO this
> doesn't fit that description. You should extract enough generic functions
> to replicate the structure of the call tree in a single short example.
>
> I suppose there could be a bug in the parameter handling, but are you sure
> every calling point is including the "..." argument that should be?
>
> My second blind point is that visibility of package variables does follow
> a complicated path, but there are good descriptions available, such as [1]
> or [2].
>
> If you do think you have found a bug, the R Core team will want a minimal
> reproducible example, and you should read the Posting Guide on bug
> reporting to make sure your issue gets addressed.
>
> [1] http://obeautifulcode.com/R/How-R-Searches-And-Finds-Stuff/
> [2] http://adv-r.had.co.nz/Environments.html
> ---------------------------------------------------------------------------
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> Sent from my phone. Please excuse my brevity.
>
> On November 14, 2014 3:51:16 PM PST, Janko Thyson <janko.thyson at gmail.com>
> wrote:
> >Dear list,
> >
> >I just encountered a behavior that I've never seen before:
> >
> >Is it possible, that certain argument names (lazy in my case) are
> >special/reserved and thus would lead to unexpected behavior when a
> >calling
> >stack is involved that spreads across functions of three different
> >packages: optionr::setAnywhereOptions() calls nestr::setNested() calls
> >reactr::setShinyReactive()?
> >
> >Or is there something I'm generally missing with respect the
> >combination of
> >lexical scoping/the frame stack, S4 and default values of function
> >arguments.
> >
> >Running the following code leads to a situation where the default value
> >of
> >`lazy` in `reactr::setShinyReactive()` is not properly recognized while
> >others (e.g. `push`) are recognized just fine:
> >
> >require("devtools")
> >devtools::install_github("Rappster/conditionr")
> >devtools::install_github("Rappster/nestr")
> >devtools::install_github("Rappster/optionr")
> >require("optionr")
> >
> >container <- initializeOptionContainer(overwrite = TRUE)
> >expect_true(setAnywhereOption(id = "x_1", value = TRUE, reactive =
> >TRUE))
> >expect_equal(getAnywhereOption(id = "x_1"), TRUE)
> >expect_true(res <- setAnywhereOption(id = "x_2",
> >  value = reactr::reactiveExpression(
> >    !getAnywhereOption(id = "x_1")
> >  ),
> >  reactive = TRUE))
> >
> >The current version of `setShinyReactive()` contains a debugging
> >section
> >that prints these status messages (the actual code:
> >https://github.com/Rappster/reactr/blob/bug-28/R/setShinyReactive.r#L196)
> >
> >DEBUG/push/before[1] FALSE
> >DEBUG/lazy/before
> >Error in print(lazy) : argument is missing, with no default
> >DEBUG/is_lazy/before[1] FALSE
> >DEBUG/lazy/after[1] FALSE
> >
> >It also contains my current workaround: also include an argument with
> >name `is_lazy` (whose default)
> >value is recognized again) and then run `lazy <- is_lazy`.
> >
> >You can also find this information in this Stackoverflow post:
> >
> http://stackoverflow.com/questions/26940474/lexical-scoping-issue-r-fails-to-recognize-an-arguments-default-value
> >
> >Thanks a lot for everyone that can shed some light on this!
> >
> >
> >Best regards,
> >Janko
> >
> >       [[alternative HTML version deleted]]
> >
> >______________________________________________
> >R-help at r-project.org mailing list
> >https://stat.ethz.ch/mailman/listinfo/r-help
> >PLEASE do read the posting guide
> >http://www.R-project.org/posting-guide.html
> >and provide commented, minimal, self-contained, reproducible code.
>
>

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