[SPARK-9316] [SPARKR] Add support for filtering using [ (synonym for filter / select)

[felixcheung]

Add support for

   df[df$name == "Smith", c(1,2)]
   df[df$age %in% c(19, 30), 1:2]

@shivaram

[shivaram]

Jenkins, ok to test

[shivaram]

cc @sun-rui @falaki

[SparkQA]

Test build #41458 has finished for PR 8394 at commit 16e0ba3.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[sun-rui]

... seems not necessary? It allows user pass parameters that won't be used, which may be confusing.

[felixcheung]

Are you referring to ...?
You are probably right... I'm more or less following line 938 above - since this is a i-not-missing overload of the operator/method.

 setMethod("[", signature(x = "DataFrame", i = "missing"),
           function(x, i, j, ...) {

setMethod("[", signature(x = "DataFrame", i = "Column"),
          function(x, i, j, ...) {

Perhaps we should take both out? But that would be a breaking change.

[shivaram]

So we need the ... to match the signature of [ in base R. From the help page you can see that the signatures look like

     x[i]
     x[i, j, ... , drop = TRUE]
     x[[i, exact = TRUE]]
     x[[i, j, ..., exact = TRUE]]

[shivaram]

Also FYI the Matrix package which also uses S4 is a good example for things like this
https://github.com/rforge/matrix/blob/master/pkg/Matrix/R/Matrix.R#L457

[sun-rui]

LGTM. some minor comments.

[SparkQA]

Test build #41517 has finished for PR 8394 at commit 3578ba2.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[shivaram]

Thanks @felixcheung -- this LGTM to me as well

[SparkQA]

Test build #41599 has finished for PR 8394 at commit 0fde873.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[shivaram]

Thanks @felixcheung -- Merging this