Split Join

wiki

-- Concat the contents of the parameter list,
-- separated by the string delimiter (just like in perl)
-- example: strjoin(", ", {"Anna", "Bob", "Charlie", "Dolores"})
function strjoin(delimiter, list)
  local len = getn(list)
  if len == 0 then 
    return "" 
  end
  local string = list[1]
  for i = 2, len do 
    string = string .. delimiter .. list[i] 
  end
  return string
end

-- Split text into a list consisting of the strings in text,
-- separated by strings matching delimiter (which may be a pattern). 
-- example: strsplit(",%s*", "Anna, Bob, Charlie,Dolores")
function strsplit(delimiter, text)
  local list = {}
  local pos = 1
  if strfind("", delimiter, 1) then -- this would result in endless loops
    error("delimiter matches empty string!")
  end
  while 1 do
    local first, last = strfind(text, delimiter, pos)
    if first then -- found?
      tinsert(list, strsub(text, pos, first-1))
      pos = last+1
    else
      tinsert(list, strsub(text, pos))
      break
    end
  end
  return list
end

(PeterPrade)

--Written for 5.0; could be made slightly cleaner with 5.1
--Splits a string based on a separator string or pattern;
--returns an array of pieces of the string.
--(May optionally supply a table as the third parameter which will be filled with the results.)
function string:split( inSplitPattern, outResults )
  if not outResults then
    outResults = { }
  end
  local theStart = 1
  local theSplitStart, theSplitEnd = string.find( self, inSplitPattern, theStart )
  while theSplitStart do
    table.insert( outResults, string.sub( self, theStart, theSplitStart-1 ) )
    theStart = theSplitEnd + 1
    theSplitStart, theSplitEnd = string.find( self, inSplitPattern, theStart )
  end
  table.insert( outResults, string.sub( self, theStart ) )
  return outResults
end

(GavinKistner)

Note: Possibly merge some of split/join content in StringRecipes and SplitJoin.

--- Unless I'm missing something, in 5.1, this DOES NOT WORK at all -- what are strsub and strfind?

VersionNotice: Those functions are from Lua 4.0[2]. This code should be updated.