Merge pull request #10 from dmi3kno/master

Added `rx_word_char()`, `rx_word_edge()`, extended `rx_count()`

DESCRIPTION

@@ -5,9 +5,9 @@ Authors@R: c(
     person("Tyler", "Littlefield", email = "[email protected]", role = c("aut", "cre")),
     person("Dmytro", "Perepolkin", email = "[email protected]", role = c("ctb"), comment=c(ORCID="0000-0001-8558-6183")))
 Description: The goal of `RVerbalExpressions` is to make it easier to construct 
-    regular expressions using rammar and functionality inspired by 
+    regular expressions using grammar and functionality inspired by 
     [VerbalExpressions](https://github.com/VerbalExpressions). Usage of the 
-    `%>%` is encouraged to build expressions in a chain like fashion.
+    `%>%` is encouraged to build expressions in a chain-like fashion.
 License: MIT + file LICENSE
 Encoding: UTF-8
 LazyData: true

NAMESPACE

@@ -35,5 +35,7 @@ export(rx_uppercase)
 export(rx_whitespace)
 export(rx_with_any_case)
 export(rx_word)
+export(rx_word_char)
+export(rx_word_edge)
 export(sanitize)
 importFrom(magrittr,"%>%")

NEWS.md

@@ -6,4 +6,5 @@
 * Add `rx()` constructor (#4)
 * Added lazy mode for `rx_anything()`, `rx_anything_but()`, `rx_something()`, `rx_something_but()`.
 * Added `rx_lowercase()`, `rx_uppercase()`, `rx_alnum()`, `rx_alpha()`.
+* Added `rx_word_char()`, `rx_word_edge()`, extended `rx_count()` to ranges of repetition 
 

R/count.R

@@ -3,7 +3,10 @@
 #' @description This function simply adds a \code{{n}} to the end of the expression.
 #'
 #' @param .data Expression to append, typically pulled from the pipe \code{ \%>\% }
-#' @param n Number of times previous expression shall be repeated. Default is 1.
+#' @param n Number of times previous expression shall be repeated.
+#' For exact number of repetitions use single number. Use sequence \code{min:max} or vector of \code{c(min, max)} to denote range of repetitions.
+#' To create ranges unbounded on one end, pass on a vector with either first of second element equal to \code{NA}, e.g. \code{c(NA, 3)},
+#' up to 3 repetitions.
 #'
 #' @examples
 #' rx_count()
@@ -20,5 +23,9 @@
 #'
 #' @export
 rx_count <- function(.data = NULL, n = 1) {
+  if(length(n)>1){
+    n[is.na(n)]<-""
+    return(paste0(.data, "{", n[1], "," , n[length(n)], "}"))
+  }
   paste0(.data, "{", n,"}")
 }

R/word.R

@@ -22,3 +22,50 @@
 rx_word <- function(.data = NULL) {
   paste0(.data, "\\w+")
 }
+
+
+#' Find beginning or end of a word.
+#'
+#' @description Match beginning or end of a word—a string consisting of of word characters (a–z, A–Z, 0–9 or _).
+#'
+#' @param .data Expression to append, typically pulled from the pipe \code{ \%>\% }
+#'
+#' @examples
+#' rx_word_edge()
+#'
+#'x <- rx_word_edge() %>%
+#'  rx_alpha() %>%
+#'  rx_one_or_more() %>%
+#'  rx_word_edge()
+#'
+#'# create inputs
+#'string1 <- "foobar"
+#'string2 <- "foo 23a bar"
+#'
+#'# matches 'foobar'
+#'regmatches(string1, regexpr(x, string1))
+#'# matches 'foo' and 'bar' separately
+#'regmatches(string2, gregexpr(x, string2))
+#' @export
+rx_word_edge <- function(.data = NULL){
+  paste0(.data, "\\b")
+}
+
+
+#' Match a word character.
+#'
+#' @description Match a word character (a–z, A–Z, 0–9 or _).
+#'
+#' @param .data Expression to append, typically pulled from the pipe \code{ \%>\% }
+#'
+#' @examples
+#' rx_word_char()
+#'
+#' # Same as rx_word()
+#'x <- rx_word_char() %>%
+#'  rx_one_or_more()
+#'
+#' @export
+rx_word_char<- function(.data = NULL){
+  paste0(.data, "\\w")
+}