Use highr by default and depend on it

DESCRIPTION

@@ -17,10 +17,10 @@ Depends:
     R (>= 3.0.1)
 Imports:
     utils,
-    grDevices
+    grDevices,
+    highr
 Suggests:
     methods,
-    highr,
     Cairo,
     testthat
 Enhances: data.table, dplyr, htmlwidgets

NAMESPACE

@@ -76,6 +76,7 @@ importFrom(grDevices,pdf)
 importFrom(grDevices,png)
 importFrom(grDevices,replayPlot)
 importFrom(grDevices,svg)
+importFrom(highr,hilight)
 importFrom(tools,Rd2HTML)
 importFrom(tools,Rd2latex)
 importFrom(tools,Rd2txt)

R/options.r

@@ -38,7 +38,7 @@
 #' 	\code{end} mainly exists for when you want a vertical line there (default: 'r|', 'l', and '')
 #' }
 #' \item{\code{repr.function.highlight}}{
-#'  Use the \code{highr} package to insert highlighting instructions into the code? Needs that package to be installed. (default: FALSE)
+#'  Use the \code{highr} package to insert highlighting instructions into the code? (default: TRUE)
 #' }
 #' 
 #' }
@@ -64,7 +64,7 @@ class_defaults <- list(
 	repr.matrix.max.rows = 60,
 	repr.matrix.max.cols = 20,
 	repr.matrix.latex.colspec = list(row_head = 'r|', col = 'l', end = ''),
-	repr.function.highlight = FALSE)
+	repr.function.highlight = TRUE)
 
 #' @name repr-options
 #' @export

R/repr_function.r

@@ -10,12 +10,11 @@
 #' @include utils.r
 NULL
 
+#' @importFrom highr hilight
 repr_function_generic <- function(f, fmt, escape, high_wrap, norm_wrap, highlight) {
 	code <- deparse(f)
 	if (highlight) {
-		if (!requireNamespace('highr'))
-			stop(sprintf('Tried to create a %s representation of a function with highlighting, but the `highlight` package is not installed!', fmt))
-		code <- highr::hilight(code, fmt)
+		code <- hilight(code, fmt)
 		wrap <- high_wrap
 	} else {
 		code <- escape(code)

README.md

@@ -27,11 +27,10 @@ Exports
 Imports
 -------
 
-Per default, `repr` will not use any packages not part of the R distribution.
-
-Only if you want to use `repr_html.function` and `repr_latex.function`, and specify the parameter `highlight` or option `repr.function.highlight` to be `TRUE`, then be sure to have [highr][] installed.
+`repr` uses [highr][] to highlight functions, and can optionally improve plot output quality via [Cairo][].
 
 [highr]: https://github.com/yihui/highr
+[Cairo]: https://rforge.net/Cairo/
 
 Formats
 -------