feat: add fixed = TRUE argument to cursor_reach

fix #567

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: officer
 Type: Package
 Title: Manipulation of Microsoft Word and PowerPoint Documents
-Version: 0.6.6.002
+Version: 0.6.6.003
 Authors@R: c(
     person("David", "Gohel", role = c("aut", "cre"), email = "david.gohel@ardata.fr"),
     person("Stefan", "Moog", role = "aut", email = 'moogs@gmx.de'),

NEWS.md

@@ -7,6 +7,8 @@
 ## Features
 
 - add coverage to rtf, contributions from Davide Garolini at roche.
+- `cursor_reach()` gains new argument `fixed` to enable exact matching.
+It defaults to FALSE for backward compatibility.
 
 # officer 0.6.5
 

R/docx_cursor.R

@@ -131,11 +131,12 @@ cursor_end <- function(x) {
 #' @export
 #' @rdname cursor
 #' @param keyword keyword to look for as a regular expression
+#' @param fixed logical. If TRUE, pattern is a string to be matched as is.
 #' @section cursor_reach:
 #' Set the cursor on the first element of the document
 #' that contains text specified in argument \code{keyword}.
 #' The argument \code{keyword} is a regexpr pattern.
-cursor_reach <- function(x, keyword) {
+cursor_reach <- function(x, keyword, fixed = FALSE) {
   nodes_with_text <- xml_find_all(
     x$doc_obj$get(),
     "/w:document/w:body/*|/w:ftr/*|/w:hdr/*"
@@ -146,7 +147,7 @@ cursor_reach <- function(x, keyword) {
   }
 
   text_ <- xml_text(nodes_with_text)
-  test_ <- grepl(pattern = keyword, x = text_)
+  test_ <- grepl(pattern = keyword, x = text_, fixed = fixed)
   if (!any(test_)) {
     stop(keyword, " has not been found in the document", call. = FALSE)
   }