char.expand: Expand a String with Respect to a Target Table

Description

Seeks a unique match of its first argument among the elements of its second. If successful, it returns this element; otherwise, it performs an action specified by the third argument.

Usage

char.expand(input, target, nomatch = stop("no match"))

Arguments

input

a character string to be expanded.

target

a character vector with the values to be matched against.

nomatch

an R expression to be evaluated in case expansion was not possible.

Value

A length-one character vector, one of the elements of target (unless nomatch is changed to be a non-error, when it can be a zero-length character string).

Details

This function is particularly useful when abbreviations are allowed in function arguments, and need to be uniquely expanded with respect to a target table of possible values.

Examples

Run this code

locPars <- c("mean", "median", "mode")
char.expand("me", locPars, warning("Could not expand!"))
char.expand("mo", locPars)