Type:	Package
Title:	Shorthand if-Else
Version:	0.1.0
Maintainer:	Dawid Kałędkowski <dawid.kaledkowski@gmail.com>
Description:	Short hand if-else function to easily switch the values depending on a logical condition.
License:	GPL-2 | GPL-3 [expanded from: GPL (≥ 2)]
BugReports:	https://github.com/gogonzo/ox/issues
Encoding:	UTF-8
Language:	en-US
Depends:	R (≥ 3.0)
Suggests:	checkmate, dplyr, magrittr, knitr, rmarkdown, testthat, utils
RoxygenNote:	7.1.2
VignetteBuilder:	knitr
NeedsCompilation:	no
Packaged:	2021-12-14 07:10:41 UTC; gonzo
Author:	Dawid Kałędkowski [aut, cre], Paweł Rucki [aut]
Repository:	CRAN
Date/Publication:	2021-12-15 09:00:02 UTC

Utility function to run OX

Description

Utility function to run OX

Usage

OX_default(
  .f,
  ...,
  .then = list(...)[[1]],
  .else = rev(list(...))[[1]],
  .invert = FALSE
)

Arguments

Checks .then and .else for OX

Description

Checks if .then and .else are fine. If they have supported classes and if their length is the same.

Usage

check_thenelse_OX(.then, .else)

Arguments

Value

NULL invisible.

Indices inversion

Description

Inverts the indices to select the rest. For example when idx is logical then ⁠[!idx]⁠, if integer then ⁠[-idx]⁠

Usage

invert_indices(idx)

Arguments

Value

object identical to idx input but with inverted values.

Short hand if-else

Description

Short hand if-else functions for simple values switching.

Usage

ox(.f, ..., .then = list(...)[[1]], .else = rev(list(...))[[1]])

xo(.f, ..., .then = list(...)[[1]], .else = rev(list(...))[[1]])

Arguments

Details

ox evaluates function .f which returns a single logical value and depending on the result ox returns:

• on TRUE returns .then.

• on FALSE returns .else.

It's important to note is that .then and .else have a default values set as the first and the last element of the .... This means that they don't have to be specified if both are arguments of .f.
If any of them are not arguments of .f then this argument should be specified directly as .then or .else, otherwise it will be passed to the function.

As, far as .then and .else won't be specified order of arguments in ... matters for ox but it's up to you if they are passed in the correct order to the .f. Then one, might consider name the argument so .f will be executed as expected. Consider following example

greater_than_by <- function(x, y, by) x > (y + by)
ox(greater_than_by, x = 5, by = 3, y = 3)

In above, one needs to move y to the end so that it will be considered as .else.

To invert the switch one can use xo which is equivalent of ox(Negate(.f), ..., .then, .else).

Value

object identical to .then or .else depending on the condition result.

Examples

# if (is.null(NULL)) NULL else 1
ox(NULL, .f = is.null, .else = 1)

# if (is("text", "character")) "text" else "not a character"
ox("text", .f = is, "character", .else = "not a character")

# if (1 > 2) 1 else 2
ox(`>`, 1, 2)
# if (!is.null(NULL)) NULL else 1
xo(NULL, .f = is.null, .else = 1)

# if (!is("text", "character")) "text" else "not a character"
xo("text", .f = is, "character", .else = "not a character")

# if (!1 > 2) 1 else 2
xo(`>`, 1, 2)

Check .f output

Description

Checks whether .f has needed length

Usage

validate_f_out(idx, len)

Arguments

Value

idx if logical and unique(idx) if numeric.

Vectorized ox

Description

Switch the values of the vector by another on specific indices.

Usage

OX(.f, ..., .then = list(...)[[1]], .else = rev(list(...))[[1]])

XO(.f, ..., .then = list(...)[[1]], .else = rev(list(...))[[1]])

Arguments

Details

#' OX evaluates function .f which returns a vector of indices which are then decide which values of .then are replaced by ⁠else⁠.

.then[!idx] <- .else[!idx]

Consequence of above is that idx = .f(...) should be a logical vector or integer vector which would be valid indices for .then and .else. This means that .then and .else should be of the same length, but there are two exceptions:

• when .else is a single value, than this value will replace .then at returned indices .then[!idx] <- .else

• when .else is NULL

To invert the switch one can use XO which is equivalent of OX(Negate(.f), ..., .then, .else).

Value

atomic or list. Returned object is a .then object with elements replaced by .else depending on a result of the logical condition.

Examples

# switch values of the vector when condition is true
OX(is.na, c(1, NA, 3), .else = c(2, 2, 2))

# use OX to invert negate the condition
XO(is.na, c(1, NA, 3), .else = c(2, 2, 2))