R/modifyHelpers.R

In NMsim: Seamless 'Nonmem' Simulation Platform

##' Create function that adds text elements to vector
##'
##' Namely used to feed functions to modify control streams using
##' `NMsim()` arguments such as `modify`. Those functions are often
##' onveniently passed a function. `add` and `overwrite` are simple
##' shortcuts to creating such functions. Make sure to see examples.
##' @param ... Elements to add.
##' @param .pos Either "top" or "bottom". Decides if new text is
##'     prepended or appended to existing text.
##' @return A function that adds the specified text to character
##'     vectors
##' @examples
##' myfun <- add("b","d")
##' myfun("a")
##' ## If more convenient, you can add a vector instead.
##' myfun2 <- add(c("b","d"))
##' myfun2("a")
##' myfun3 <- add("b","d",.pos="top")
##' myfun3("a")
##' @export
add <- function(...,.pos="bottom"){
    
    switch(.pos,
           top=function(x)c(unlist(list(...)),x),
           bottom=function(x)c(x,unlist(list(...)))
           )
    
}

##' Create function that modifies text elements in a vector Namely
##' used to feed functions to modify control streams using `NMsim()`
##' arguments such as `modify`. Those functions are often onveniently
##' passed a function. `add` and `overwrite` are simple shortcuts to
##' creating such functions. Make sure to see examples.
##' @param ... Passed to `gsub()`
##' @param fixed This is passed to gsub(), but `overwrite()`'s default
##'     behavior is the opposite of the one of `gsub()`. Default is
##'     `FALSE` which means that strings that are exactly matched will
##'     be replaced. This is useful because strings like `THETA(1)`
##'     contains special characters. Use `fixed=FALSE` to use regular
##'     expressions. Also, see other arguments accepted by `gsub()`
##'     for advanced features.
##' @return A function that runs `gsub` to character vectors
##' @examples
##' myfun <- overwrite("b","d")
##' myfun(c("a","b","c","abc"))
##' ## regular expressions
##' myfun2 <- overwrite("b.*","d",fixed=FALSE)
##' myfun2(c("a","b","c","abc"))
##' @export
overwrite <- function(...,fixed=TRUE){
    
    function(x){
        do.call(gsub,
                append(list(...),list(x=x,fixed=fixed))
                )
    }
}