#' @title Compare two character elements
#' @description Logical test if two character elements are identical
#' @param s1 first character element (string, vector or matrix)
#' @param s2 second character element (string, vector or matrix)
#' @return a logical element of the same type as the input
#' @export
strcmp <- function(s1, s2) {
    if (length(s1) == 1 & length(s2) == 1) {
        # Both are scalars, comparison is straightforward
        return(identical(s1, s2))
    } else if (length(s1) == 1 & length(s2) > 1) {
        # s1 is a scalar and s2 is a vector or a matrix
        checks <- sapply(s2, function(s) s1 %in% s)
        if (is(s2, "matrix")) checks <- matrix(checks, nrow(s2))
    } else if (length(s1) > 1 & length(s2) == 1) {
        # s1 is a vector/matrix, s2 is a scalar
        checks <- sapply(s1, function(s) s2 %in% s)
        if (is(s1, "matrix")) checks <- matrix(checks, nrow(s1))
    } else {
        # s1 and s2 are vectors/matrices
        if (identical(dim(s1), dim(s2))) {
            checks <- as.matrix(s4 == s5)
        } else {
            stop("Inputs must be the same size or either one can be a scalar.")
        }
    }
    return(checks)
}