[R-Forge #5399] %between% could be vectorised

[arunsrinivasan]

Submitted by: Michele Carriero; Assigned to: Nobody; R-Forge link

As implemented now

between(x, y[1], y[2], incbounds = TRUE)

%between% has only a single upper and lower bound. Replacing its body with

between(x, y[[1]], y[[2]], incbounds = TRUE)

would allow the current usage plus a vectorised usage. Like:

dt[ colA %between% list(colB, colC)]

[arunsrinivasan]

Hm, currently between() checks which values of x is between y and z (length=1 as it were before this commit). In that sense, if it has to be vectorised, then the Q we could instead ask is:

Is x between any of the ranges between y and z?

In essence, we could promote current vectorised behaviour to do even more -- true range join/subset. Will do and then close.

[arunsrinivasan]

Implemented new function anywhere() that does a range join.. See #679