Logical infix operator for possibly NULL objects

[wlandau]

Some packages define an internal %||% operator to make a decision based on whether an object is NULL. I find this helps make code more compact and readable.

`%||%` <- function(x, y) {
  if (is.null(x)) {
    y
  } else {
    x
  }
}

I personally also use %|||% and %||NA, but maybe that's a bit much.

`%|||%` <- function(x, y) {
  if (!length(x)) {
    y
  } else {
    x
  }
}

`%||NA%` <- function(x, y) {
  if (anyNA(x)) {
    y
  } else {
    x
  }
}

[gmbecker]

depending on the purpose, though, %||% could also reasonably be defined as what you're calling %|||%.

Also, and more importantly, there are some gotchas here. Big, sharp-edged ones, regarding operator precedence:

lobstr::ast(x=a %||% b & c)

█─&

├─█─%||%

│ ├─a

│ └─b

└─c

On Wed, Feb 10, 2021 at 11:31 AM Will Landau notifications@github.com wrote:

Some packages define an internal %||% operator to make a decision based on whether an object is NULL. I find this helps make code more compact and readable.

%||% <- function(x, y) { if (is.null(x)) { y } else { x } }

I personally also use %|||% and %||NA, but maybe that's a bit much.

%|||% <- function(x, y) { if (!length(x)) { y } else { x } } %||NA% <- function(x, y) { if (anyNA(x)) { y } else { x } }

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[HenrikBengtsson]

I think you've been heard;

$ R --vanilla
R Under development (unstable) (2023-10-26 r85413) -- "Unsuffered Consequences"
...
> x <- NULL
> x %||% 42
[1] 42

Source: https://github.com/wch/r-source/commit/10df7eac991c297271e16c7a1888240196d540f2

[HenrikBengtsson]

Closing; %||% is available in R (>= 4.4.0).