[Rd] detect ->

Adrian Dușa du@@@@dr|@n @end|ng |rom gm@||@com
Wed Apr 15 12:45:11 CEST 2020

> On 15 Apr 2020, at 13:20, Ivan Krylov <krylov.r00t using gmail.com> wrote:
> On Wed, 15 Apr 2020 10:41:41 +0300
> Adrian Dușa <dusa.adrian using gmail.com> wrote:
>> Now, if I could find a way to define "=>" as a standalone operator,
>> and convince the R parser to bypass that error, it would solve
>> everything. If this is not possible, I am back to detecting "->".
> Just to confirm, are you avoiding custom %operators% because of two
> extra percent characters one would have to type per operator?

Yes, that's right. The "->" operator is the standard way to signal sufficiency into a SOP (sum of products) expression, something like:

A~BC + BC~D + E -> Y

This is consistently used in many books and articles, and currently the standard when quoted:

"A~BC + BC~D + E -> Y"

To require using the %% notation in unquoted strings would make the SOP expression different from the quoted one, which is likely to create confusion:

A~BC + BC~D + E %->% Y

If detecting "->" proves to be impossible, then I will probably have no choice but to stick with quoted expressions. I am just hoping the collective knowledge here would make this possible, though.


Adrian Dusa
University of Bucharest
Romanian Social Data Archive
Soseaua Panduri nr. 90-92
050663 Bucharest sector 5

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