

   CCllaassss ffoorr ````nnoo qquuoottee'''' PPrriinnttiinngg ooff SSttrriinnggss

        noquote(obj)
        print.noquote(obj, ...)
        obj[j]

   AArrgguummeennttss::

        obj: any object; typically a vector of `character'
             strings.

        ...: further options for `print'.

   DDeessccrriippttiioonn::

        These functions exist both as utilities and as an exam-
        ple of using `class' and object orientation.

   VVaalluuee::

        `noquote' returns its argument as an object of class
        `"noquote"'.  The function `"[.noquote"' ensures that
        the class is not lost by subsetting.

        For (default) printing, `print.noquote' will be used
        which prints characters without quotes (`"..."').

   AAuutthhoorr((ss))::

        Martin Maechler maechler@stat.math.ethz.ch

   SSeeee AAllssoo::

        `methods',`class',`print'.

   EExxaammpplleess::

        letters
        nql <- noquote(letters)
        nql
        nql[1:4] <- "oh"
        nql[1:12]

        cmp.logical <- function(log.v)
        {
          ## Purpose: compact printing of logicals
          if(!is.logical(log.v)) {
            warning("coercing argument 'log.v' to logical")
            log.v <- as.logical(log.v)
          }
          structure(if(length(log.v)==0)"()" else c(".","|")[1+log.v],
                 class = "noquote")
        }
        cmp.logical(runif(20) > 0.8)

