src/library/methods/R/cbind.R

#  File src/library/methods/R/cbind.R
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#### cbind() and rbind()  which build on  cbind2() / rbind2()
#### --------------------------------------------------------
### NOTE: We rely on
### o	dim(.) working reliably for all arguments of [cr]bind2()
### o	All [cr]bind2() methods are assumed to
###	correctly *use* (row/col)names of their matrix arguments
###     but cannot look at arguments for deparsing them
###  => all (row/col)names setting depending on deparse.level must be done *here

### Note that this
### 1) is namespace-hidden usually,
### 2) cbind / rbind are almost never called in 'methods' itself
### hence, the following has almost no effect unless ``activated'' (see below)

## rbind() is in ./rbind.R  {so it's easier to keep them 100% - synchronized !}

cbind <- function(..., deparse.level = 1)
{
    has.dl <- !missing(deparse.level)
    deparse.level <- as.integer(deparse.level)
    if(identical(deparse.level, -1L)) deparse.level <- 0L # our hack
    stopifnot(0 <= deparse.level, deparse.level <= 2)

    argl <- list(...)
    ## remove trailing 'NULL's:
    na <- nargs() - has.dl
    while(na > 0L && is.null(argl[[na]])) { argl <- argl[-na]; na <- na - 1L }
    if(na == 0) return(NULL)
    symarg <- as.list(substitute(list(...)))[-1L] # symbolic argument (names)
    nmsym <- names(symarg)
    ## Give *names* depending on deparse.level {for non-matrix}:
    nm <- c( ## 0:
	function(i) NULL,
	## 1:
	function(i) if(is.symbol(s <- symarg[[i]])) deparse(s) else NULL,
	## 2:
	function(i) deparse(symarg[[i]])[[1L]])[[ 1L + deparse.level ]]
    Nms <- function(i) { if(!is.null(s <- nmsym[i]) && nzchar(s)) s else nm(i) }
    if(na == 1) {
	if(isS4(..1)) {
	    r <- cbind2(..1)
	    if(length(dim(..1)) < 2L && length(dim(r)) == 2L)
		colnames(r) <- Nms(1)
	    return(r)
	}
	else return(base::cbind(..., deparse.level = deparse.level))
    }

    ## else :  na >= 2

    if(na == 2) {
	fix.na <- FALSE
    }
    else { ## na >= 3 arguments
	## determine nrow(<result>)  for e.g.,	cbind(diag(2), 1, 2)
	## only when the last two argument have *no* dim attribute:
	nrs <- unname(lapply(argl, nrow)) # of length na
	iV <- vapply(nrs, is.null, NA)# is 'vector'
	fix.na <- identical(nrs[(na-1L):na], list(NULL,NULL))
	if(fix.na) {
	    ## "fix" last argument, using 1-column `matrix' of proper nrow():
	    nr <- max(if(all(iV)) lengths(argl) else unlist(nrs[!iV]))
	    argl[[na]] <- cbind(rep(argl[[na]], length.out = nr),
				deparse.level = 0)
	    ## and since it's a 'matrix' now, cbind() below may not name it
	}
	## if(deparse.level) {
	    if(fix.na)
		fix.na <- !is.null(Nna <- Nms(na))
	## }
    }

    Ncol <- function(x) {
	d <- dim(x); if(length(d) == 2L) d[2L] else as.integer(length(x) > 0L) }
    setN <- function(i, nams)
	colnames(r)[i] <<- if(is.null(nams)) "" else nams

    r <- argl[[na]]
    for(i in (na-1L):1L) {
    d2 <- dim(r)
    r <- cbind2(argl[[i]], r)
    ## if(deparse.level == 0)
    ##     if(i == 1L) return(r) else next
    ism1 <- !is.null(d1 <- dim(argl[[i]])) && length(d1) == 2L
    ism2 <- !is.null(d2)                   && length(d2) == 2L
    if(ism1 && ism2) ## two matrices
	next

    ## else -- Setting colnames correctly
    ##	       when one was not a matrix [needs some diligence!]
    nn1 <- !is.null(N1 <- if(       (l1 <- Ncol(argl[[i]])) && !ism1) Nms(i)) # else NULL
    nn2 <- !is.null(N2 <- if(i == na-1L && Ncol(argl[[na]]) && !ism2) Nms(na))
    if(nn1 || nn2) {
	if(is.null(colnames(r)))
	    colnames(r) <- rep.int("", ncol(r))
	if(nn1) setN(1,	 N1)
	if(nn2) setN(1+l1, N2)
    }
    }

    if(fix.na) {
	if(is.null(colnames(r)))
	    colnames(r) <- rep.int("", ncol(r))
	setN(ncol(r), Nna)
    }
    r
}

### cbind2 () :	 Generic and methods need to be "method-bootstrapped"
### --------   --> ./MethodsListClass.R