Merge pull request #37 from jimhester/master

Add function to word wrap long character vectors

NAMESPACE

@@ -81,6 +81,7 @@ export(trans_breaks)
 export(trans_format)
 export(trans_new)
 export(trans_range)
+export(wrap_format)
 export(zero_range)
 import(Rcpp)
 import(methods)

NEWS

@@ -1,6 +1,9 @@
 Version 0.2.5
 ------------------------------------------------------------------------------
 
+* `wrap_format()` function to wrap character vectors to a desired width.
+  (@jimhester, #37).
+
 * Dollar format is now more flexible and can add either prefixes or suffixes
   for different currencies (#53).
 

R/formatter.r

@@ -163,6 +163,21 @@ math_format <- function(expr = 10 ^ .x, format = force) {
 }
 globalVariables(".x")
 
+#' Wrap text to a specified width, adding newlines for spaces if text exceeds
+#' the width
+#'
+#' @param width value above which to wrap
+#' @return Function with single parameter x, a character vector, that
+#'    returns a wrapped character vector
+#' @export
+#' @examples
+#' wrap_10 <- wrap_format(10)
+#' wrap_10('A long line that needs to be wrapped')
+wrap_format <- function(width) {
+  function(x) {
+    unlist(lapply(strwrap(x, width = width, simplify = FALSE), paste0, collapse = "\n"))
+  }
+}
 #' Format labels after transformation.
 #'
 #' @param trans transformation to apply

man/wrap_format.Rd

@@ -0,0 +1,25 @@
+% Generated by roxygen2 (4.1.1): do not edit by hand
+% Please edit documentation in R/formatter.r
+\name{wrap_format}
+\alias{wrap_format}
+\title{Wrap text to a specified width, adding newlines for spaces if text exceeds
+the width}
+\usage{
+wrap_format(width)
+}
+\arguments{
+\item{width}{value above which to wrap}
+}
+\value{
+Function with single parameter x, a character vector, that
+   returns a wrapped character vector
+}
+\description{
+Wrap text to a specified width, adding newlines for spaces if text exceeds
+the width
+}
+\examples{
+wrap_10 <- wrap_format(10)
+wrap_10('A long line that needs to be wrapped')
+}
+

tests/testthat/test-formatter.r

@@ -55,6 +55,17 @@ test_that("dollar format", {
   expect_equal(dollar(c(99.999)), c("$100"))
 })
 
+test_that("wrap correctly wraps long lines", {
+  expect_equal(wrap_format(10)("this is a long line"),
+               "this is a\nlong line")
+  expect_equal(wrap_format(10)(c("this is a long line", "this is another long line")),
+               c("this is a\nlong line", "this is\nanother\nlong line"))
+  expect_equal(wrap_format(10)("a_very_long_word_without_spaces"),
+               "a_very_long_word_without_spaces")
+  expect_equal(wrap_format(10)("short line"), "short\nline")
+  expect_equal(wrap_format(15)("short line"), "short line")
+})
+
 test_that("formatters don't add extra spaces", {
   has_space <- function(x) any(grepl("\\s", x))
   x <- 10 ^ c(-1, 0, 1, 3, 6, 9)