R/methods.R

In smbache/squr: Structured Query Utility for R

#' S3 Print Method for 'sq' Objects
#'
#' @param x an sq object to be printed.
#' @param ... Passed on to \code{cat}.
#'
#' @export
print.sq <- function(x, ...)
{
  if (!inherits(x, "sq") || !is.character(x))
    stop("Invalid sq object.")

  cat(x)

  invisible(x)
}

#' S3 Print Method for 'sq_value' Objects
#'
#' @param x an sq_value object to be printed
#' @param ... Passed to \code{print.default}.
#'
#' @export
print.sq_value <- function(x, ...)
{
  if (!inherits(x, "sq_value") || !is.character(x))
    stop("Invalid sq_value object.")

  cat("sq_value:\n")

  print(unclass(x))
  invisible(x)
}

#' Concatenate sq objects
#'
#' Concatenate two sq chunks, separated by two line breaks.
#'
#' @param e1 An \code{sq} object.
#' @param e2 An \code{sq} object.
#'
#' @return An \code{sq} object.
#'
#' @export
`+.sq` <- function(e1, e2)
{
  sq_text(paste(e1, e2, sep = "\n"))
}