[R] Question: write an R script with help information available to the user

[Gabor Grothendieck]

On Sun, Feb 3, 2013 at 1:50 AM, Bert Gunter <gunter.berton at gene.com> wrote:
> A  related approach which, if memory serves, was originally in S eons
> ago, is to define a "doc" attribute of any function (or object, for
> that matter)  that you wish to document that contains text for
> documentation and a doc() function of the form:
>
> doc <- function(obj) cat(attr(obj,"doc"))
>
> used as:
>
>> f- function(x) NULL
>> attr(f,"doc") <- "Some text\n\n"
>> doc(f)
>> doc(f)
> Some text
>
> This is pretty primitive, but I suppose you could instead have the
> attribute point to something like an HTML file and the doc() function
> open it in a web browser, which is basically what R's built-in package
> document system does anyway. Except you wouldn't have to build a
> package and don't have to learn or follow R's procedures. Which means
> you don't get  R's standardization and organization and no one but a
> private bunch of users will be able to use your function. But maybe
> that's sufficient for your needs.
>

To further build on this try the above idea using the comment function:

> f <- function() NULL
> comment(f) <- "Help goes here"
>
> comment(f)
[1] "Help goes here"

or combine it with the redefinition of ? like like this:

`?` <- function(...) if (!is.null(doc <-
comment(get(match.call()[[2]])))) cat(doc, "\n") else help(...)
?f    #  displays:  Help goes here
?dim   # normal help

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