Add as.regex and c methods

Partially addresses #10 when the `regex` object is the first object to
be Concatenated.

NAMESPACE

@@ -1,6 +1,7 @@
 # Generated by roxygen2 (4.0.2.9000): do not edit by hand
 
 S3method(as.character,regex)
+S3method(as.regex,default)
 S3method(character_class_escape,character)
 S3method(character_class_escape,character_class)
 S3method(character_class_escape,default)
@@ -18,6 +19,7 @@ export("%if_next_isnt%")
 export("%if_prev_is%")
 export("%if_prev_isnt%")
 export("%or%")
+export(as.regex)
 export(at_least)
 export(at_most)
 export(between)

R/rex.R

@@ -25,16 +25,28 @@ rex_ <- function(args, env = parent.frame()) {
   return(output)
 }
 
-#' Convert regex to a character
-#' @param x \code{regex} object.
-#' @param ... further args ignored by method.
+#' @describeIn regex coerce regex object to a character
 #' @export
-as.character.regex <- function(x, ...) escape(x)
+as.character.regex <- function(x, ...) x
 
-#' Print regex object
-#' @param x Object to be printed.
-#' @param ... further args are ignored.
+#' Coerce objects to a \code{\link{regex}}.
+#' @name as.regex
+#' @param x Object to coerce to \code{\link{regex}}.
+#' @param ... further arguments passed to methods.
 #' @export
+as.regex <- function(x, ...) UseMethod("as.regex")
+
+#' @export
+#' @describeIn as.regex Simply escape the Object.
+as.regex.default <- function(x, ...) escape(x)
+
+#' @describeIn regex concatenate regex
+c.regex <- function(...) {
+  p(escape_dots(...))
+}
+
+#' @export
+#' @describeIn regex Print regex object
 print.regex <- function(x, ...){
   cat(paste(strwrap(x), collapse = "\n"), "\n", sep = "")
 }
@@ -43,7 +55,9 @@ print.regex <- function(x, ...){
 #'
 #' Specify an explicit regular expression.  This expression must already be
 #' escaped.
-#' @param x Object to be coerced to a regex.
+#' @param x Object
+#' @param ... further arguments
+#' @seealso \code{\link{as.regex}} to coerce to a regex object.
 #' @export
-regex <- function(x) structure(x, class = "regex")
+regex <- function(x, ...) structure(x, class = "regex")
 

man/as.regex.Rd

@@ -0,0 +1,23 @@
+% Generated by roxygen2 (4.0.2.9000): do not edit by hand
+\name{as.regex}
+\alias{as.regex}
+\alias{as.regex.default}
+\title{Coerce objects to a \code{\link{regex}}.}
+\usage{
+as.regex(x, ...)
+
+\method{as.regex}{default}(x, ...)
+}
+\arguments{
+\item{x}{Object to coerce to \code{\link{regex}}.}
+
+\item{...}{further arguments passed to methods.}
+}
+\description{
+Coerce objects to a \code{\link{regex}}.
+}
+\section{Methods (by class)}{
+\itemize{
+\item \code{default}: Simply escape the Object.
+}}
+

man/regex.Rd

@@ -1,15 +1,37 @@
 % Generated by roxygen2 (4.0.2.9000): do not edit by hand
-\name{regex}
+\name{as.character.regex}
+\alias{as.character.regex}
+\alias{c.regex}
+\alias{print.regex}
 \alias{regex}
 \title{Regular Expression}
 \usage{
-regex(x)
+\method{as.character}{regex}(x, ...)
+
+\method{c}{regex}(...)
+
+\method{print}{regex}(x, ...)
+
+regex(x, ...)
 }
 \arguments{
-\item{x}{Object to be coerced to a regex.}
+\item{x}{Object}
+
+\item{...}{further arguments}
 }
 \description{
 Specify an explicit regular expression.  This expression must already be
 escaped.
 }
+\section{Methods (by generic)}{
+\itemize{
+\item \code{as.character}: coerce regex object to a character
+
+\item \code{c}: concatenate regex
+
+\item \code{print}: Print regex object
+}}
+\seealso{
+\code{\link{as.regex}} to coerce to a regex object.
+}