path.join with quoted paths

[moteus]

path.join shold unquot each element and quot result

For example:

IPPARCH="ia32"
IPPBASE=J([[e:\Program Files\Intel\IPP\6.0.2.074]], IPPARCH)
-- here i have IPPBASE= [["e:\Program Files\Intel\IPP\6.0.2.074\ia32"]]
....
incdir=J(IPPBASE, 'include')
-- here i have incdir= [["e:\Program Files\Intel\IPP\6.0.2.074\ia32\include"]]

to support this i implement:

function trim(s) return(s:gsub('^%s+',''):gsub('%s+$','')) end

function path_unquoted(s)
  s = trim(s)
  if s:sub(1,1) == '"' and s:sub(-1,-1) == '"' then
    return (s:sub(2,-2))
  end
  return s
end

function path_quoted(s)
  if s:find("%s") then return '"' .. s .. '"' end
  return s
end

function J(...)
  local t,n = {...}, select('#', ...)
  local r = path_unquoted(t[1])
  for i = 2, #t do r = path.join(r,path_unquoted(t[i])) end
  return path_quoted(r)
end

[stevedonovan]

Thanks, that is necessary. Internally I am keeping paths-with-spaces quoted, even on Unix.