Add plot.R6 method, which calls $plot on object. Closes #77

DESCRIPTION

@@ -21,3 +21,4 @@ License: MIT + file LICENSE
 URL: https://github.com/wch/R6/
 LazyData: true
 VignetteBuilder: knitr
+RoxygenNote: 5.0.1

NAMESPACE

@@ -1,7 +1,8 @@
-# Generated by roxygen2 (4.1.1): do not edit by hand
+# Generated by roxygen2: do not edit by hand
 
 S3method(format,R6)
 S3method(format,R6ClassGenerator)
+S3method(plot,R6)
 S3method(print,R6)
 S3method(print,R6ClassGenerator)
 export(R6Class)

NEWS

@@ -1,3 +1,9 @@
+R6 2.1.2.9000
+-------------------------------------------------------------------------------
+
+* The `plot` S3 method for R6 objects will call `$plot` on the object if
+  present. (#77)
+
 R6 2.1.2
 -------------------------------------------------------------------------------
 

R/print.R

@@ -131,3 +131,13 @@ trim <- function(str, n = 60) {
   if (nchar(str) > n) paste(substr(str, 1, 56), "...")
   else str
 }
+
+
+#' @export
+plot.R6 <- function(x, ...) {
+  if (is.function(x$plot)) {
+    x$plot(...)
+  } else {
+    stop(paste0("No plot method defined for R6 class ", class(x)[1]))
+  }
+}