| % File src/library/base/man/char.expand.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2008 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{char.expand} |
| \alias{char.expand} |
| \title{Expand a String with Respect to a Target Table} |
| \usage{char.expand(input, target, nomatch = stop("no match"))} |
| \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. |
| } |
| \arguments{ |
| \item{input}{a character string to be expanded.} |
| \item{target}{a character vector with the values to be matched |
| against.} |
| \item{nomatch}{an \R expression to be evaluated in case expansion was |
| not possible.} |
| } |
| \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. |
| } |
| \value{ |
| A length-one character vector, one of the elements of \code{target} |
| (unless \code{nomatch} is changed to be a non-error, when it can be a |
| zero-length character string). |
| } |
| \seealso{ |
| \code{\link{charmatch}} and \code{\link{pmatch}} for performing |
| partial string matching. |
| } |
| \examples{ |
| locPars <- c("mean", "median", "mode") |
| char.expand("me", locPars, warning("Could not expand!")) |
| char.expand("mo", locPars) |
| } |
| \keyword{character} |