yihui · yihui · Mar 11, 2021 · Dec 9, 2020 · Dec 13, 2020 · Feb 10, 2021
diff --git a/NAMESPACE b/NAMESPACE
@@ -32,6 +32,7 @@ export(combine_words)
 export(current_input)
 export(dep_auto)
 export(dep_prev)
+export(eng_r)
 export(engine_output)
 export(extract_raw_output)
 export(fig_chunk)

diff --git a/R/block.R b/R/block.R
@@ -118,8 +118,27 @@ block_exec = function(options) {
         ))
       }
     return(if (options$include) output else '')
+  } else {
+    eng_r(options)
   }
+}
+
 
+#' Engine for R
+#'
+#' This function handles the execution of R code blocks (when the chunk option \code{engine} is  \code{'R'})
+#' and generates the R output for each code block.
+#'
+#' This engine function has one argument \code{options}: the source code of the current chunk  is in \code{options$code}.
+#' It returns a processed output which can consist of data frames (as tables), graphs or character output.
+#' This function is intended for advanced use to allow developers to extend R,
+#' and customise the pipeline with which R code is executed and processed within knitr.
+#'
+#' @param options A list of chunk options. Usually this is just the object
+#'   \code{options} associated with the current code chunk.
+
+#' @export
+eng_r = function(options) {
   # eval chunks (in an empty envir if cache)
   env = knit_global()
   obj.before = ls(globalenv(), all.names = TRUE)  # global objects before chunk

diff --git a/man/Sweave2knitr.Rd b/man/Sweave2knitr.Rd
diff --git a/man/all_labels.Rd b/man/all_labels.Rd
diff --git a/man/all_patterns.Rd b/man/all_patterns.Rd
diff --git a/man/asis_output.Rd b/man/asis_output.Rd
diff --git a/man/chunk_hook.Rd b/man/chunk_hook.Rd
diff --git a/man/combine_words.Rd b/man/combine_words.Rd
diff --git a/man/eng_r.Rd b/man/eng_r.Rd
diff --git a/man/engine_output.Rd b/man/engine_output.Rd
diff --git a/man/fig_chunk.Rd b/man/fig_chunk.Rd
diff --git a/man/fig_path.Rd b/man/fig_path.Rd
diff --git a/man/hook_document.Rd b/man/hook_document.Rd
diff --git a/man/hook_plot.Rd b/man/hook_plot.Rd
diff --git a/man/image_uri.Rd b/man/image_uri.Rd
diff --git a/man/imgur_upload.Rd b/man/imgur_upload.Rd
diff --git a/man/inline_expr.Rd b/man/inline_expr.Rd
diff --git a/man/kable.Rd b/man/kable.Rd
diff --git a/man/knit.Rd b/man/knit.Rd
diff --git a/man/knit2html.Rd b/man/knit2html.Rd
diff --git a/man/knit_child.Rd b/man/knit_child.Rd
diff --git a/man/knit_engines.Rd b/man/knit_engines.Rd
diff --git a/man/knit_expand.Rd b/man/knit_expand.Rd