R/fnAppend.R

In NMsim: Seamless 'Nonmem' Simulation Platform

##' paste something before file name extension.
##' 
##' Append a file name like file.mod to file_1.mod or file_pk.mod. If
##' it's a number, we can pad some zeros if wanted. The separator
##' (default is underscore) can be modified.
##' @param fn The file name or file names to modify.
##' @param x A character string or a numeric to add to the file
##'     name. If a vector, the vector is collapsed to a single string,
##'     using `sep` as separator in the collapsed string.
##' @param pad0 In case x is numeric, a number of zeros to pad before
##'     the appended number. This is useful if you are generating say
##'     more than 10 files, and your counter will be 01, 02,..,
##'     10,... and not 1, 2,...,10,...
##' @param sep The separator between the existing file name (until
##'     extension) and the addition.
##' @param collapse If `x` is of length greater than 1, the default is
##'     to collapse the elements to a single string using `sep` as
##'     separator. See the `collapse` argument to `?paste`. If you
##'     want to treat them as separate strings, use `collapse=NULL`
##'     which will lead to generation of separate file names. However,
##'     currently `fn` or `x` must be of length 1.
##' @param position "append" (default) or "prepend".
##' @param allow.noext Allow `fn` to be string(s) without extensions?
##'     Default is `FALSE` in which case an error will be thrown if
##'     `fn` contains strings without extensions. If `TRUE`, `x` will
##'     be appended to fn in these cases.
##' @return A character (vector)
##' @keywords internal


## Do not export. Copied from NMdata

fnAppend <- function(fn,x,pad0=0,sep="_",collapse=sep,position="append",allow.noext=FALSE){

    if(is.null(x)) return(fn)
    
    if((!is.numeric(x)&&!is.character(x))) stop("x must be numeric or character vector.")
    position <- match.arg(position,choices=c("append","prepend")) 
    
    if(is.numeric(x)){
        ## formating padding zeros. pad0 determines the format of x in sprintf. 
        fmt <- paste0("%0",pad0,"d")
        x.string <- sprintf(fmt=fmt,x)
    } else {
        x.string <- x
    }
    x.string <- paste(x.string,collapse=collapse)

    if(length(fn)>1 && length(x.string)>1){
        stop("Both fn and x are of length>1. This is currently not supported. Is `collapse NULL`?")
    }
    
    if(all(nchar(x.string))==0) return(fn)

    ## fnAppend supports strings in fn that do not have file name
    ## extensions (not in a str/ing.ext format). An extension can be
    ## required to ensure paths are meaningful.
    has.ext <- grepl(".*[^\\.]\\.[a-zA-Z0-9]+",fn)
    if( !all(has.ext) && !allow.noext){
        stop("Elements in fn have no extension and allow.noext=FALSE")
    }

    
    if(position=="append"){
        
        allext <- rep("",length(fn))
        allext[has.ext] <- sub(".*[^\\.]\\.([a-zA-Z0-9]+)$","\\1",fn[has.ext])
        allext[has.ext] <- paste0(".",allext[has.ext])

        fnroot <- sub(paste0("\\.[a-zA-Z0-9]+$"),"",fn)
        
        return(paste0(fnroot,sep,x.string,allext))
    }

    if(position=="prepend"){
        dir <- dirname(fn)
        dir[dir!="."] <- paste0(dir[dir!="."],"/")
        dir[dir=="."] <- ""
        
        return(
            paste0(
                dir
               ,paste(x.string,basename(fn),sep=sep)
            )
            )
    }
    
}