Added lume.wordwrap(); updated README.md and tests

README.md

@@ -316,6 +316,15 @@ instead of whitespace.
 lume.trim("  Hello  ") -- Returns "Hello"
 ```
 
+### lume.wordwrap(str [, limit])
+Returns `str` wrapped to `limit` number of characters per line, by default
+`limit` is `72`. `limit` can also be a function which when passed a string,
+returns `true` if it is too long for a single line.
+```lua
+-- Returns "Hello world\nThis is a\nshort string"
+lume.wordwrap("Hello world. This is a short string", 14)
+```
+
 ### lume.format(str [, vars])
 Returns a formatted string. The values of keys in the table `vars` can be
 inserted into the string by using the form `"{key}"` in `str`; numerical keys

lume.lua

@@ -480,6 +480,32 @@ function lume.trim(str, chars)
 end
 
 
+function lume.wordwrap(str, limit)
+  limit = limit or 72
+  local check
+  if type(limit) == "number" then
+    check = function(str) return #str >= limit end
+  else
+    check = limit
+  end
+  local rtn = {}
+  for j, line in ipairs(lume.split(str, "\n")) do
+    local str
+    for i, word in ipairs(lume.split(line)) do
+      local s = (str and (str .. " ") or "") .. word
+      if check(s) then
+        rtn[#rtn + 1] = str
+        str = word
+      else
+        str = s
+      end
+    end
+    rtn[#rtn + 1] = str
+  end
+  return table.concat(rtn, "\n")
+end
+
+
 function lume.format(str, vars)
   if not vars then return str end
   local f = function(x)

test/test_lume.lua

@@ -431,6 +431,16 @@ tests["lume.trim"] = function()
   testeq( lume.trim("^.hello world]^", "^.]"),  "hello world"   )
 end
 
+-- lume.wordwrap
+tests["lume.wordwrap"] = function()
+  local str = "A small string with some words and then some more words"
+  local b = "A small string with\nsome words and then\nsome more words"
+  local fn = function(str) return #str >= 20 end
+  testeq( lume.wordwrap(str),     str )
+  testeq( lume.wordwrap(str, 20), b   )
+  testeq( lume.wordwrap(str, fn), b   )
+end
+
 -- lume.format
 tests["lume.format"] = function()
   local str = lume.format("a {a} in a {b}", {a = "mouse", b = "house"})