source/texk/web2c/luatexdir/luasocket/src/mime.lua

   1 -----------------------------------------------------------------------------
   2 -- MIME support for the Lua language.
   3 -- Author: Diego Nehab
   4 -- Conforming to RFCs 2045-2049
   5 -----------------------------------------------------------------------------
   6
   7 -----------------------------------------------------------------------------
   8 -- Declare module and import dependencies
   9 -----------------------------------------------------------------------------
  10 local base = _G
  11 local ltn12 = require("ltn12")
  12 local mime = require("mime.core")
  13 local string = require("string")
  14 module("mime")
  15
  16 -- encode, decode and wrap algorithm tables
  17 encodet = {}
  18 decodet = {}
  19 wrapt = {}
  20
  21 -- creates a function that chooses a filter by name from a given table
  22 local function choose(table)
  23     return function(name, opt1, opt2)
  24         if base.type(name) ~= "string" then
  25             name, opt1, opt2 = "default", name, opt1
  26         end
  27         local f = table[name or "nil"]
  28         if not f then
  29             base.error("unknown key (" .. base.tostring(name) .. ")", 3)
  30         else return f(opt1, opt2) end
  31     end
  32 end
  33
  34 -- define the encoding filters
  35 encodet['base64'] = function()
  36     return ltn12.filter.cycle(b64, "")
  37 end
  38
  39 encodet['quoted-printable'] = function(mode)
  40     return ltn12.filter.cycle(qp, "",
  41         (mode == "binary") and "=0D=0A" or "\r\n")
  42 end
  43
  44 -- define the decoding filters
  45 decodet['base64'] = function()
  46     return ltn12.filter.cycle(unb64, "")
  47 end
  48
  49 decodet['quoted-printable'] = function()
  50     return ltn12.filter.cycle(unqp, "")
  51 end
  52
  53 local function format(chunk)
  54     if chunk then
  55         if chunk == "" then return "''"
  56         else return string.len(chunk) end
  57     else return "nil" end
  58 end
  59
  60 -- define the line-wrap filters
  61 wrapt['text'] = function(length)
  62     length = length or 76
  63     return ltn12.filter.cycle(wrp, length, length)
  64 end
  65 wrapt['base64'] = wrapt['text']
  66 wrapt['default'] = wrapt['text']
  67
  68 wrapt['quoted-printable'] = function()
  69     return ltn12.filter.cycle(qpwrp, 76, 76)
  70 end
  71
  72 -- function that choose the encoding, decoding or wrap algorithm
  73 encode = choose(encodet)
  74 decode = choose(decodet)
  75 wrap = choose(wrapt)
  76
  77 -- define the end-of-line normalization filter
  78 function normalize(marker)
  79     return ltn12.filter.cycle(eol, 0, marker)
  80 end
  81
  82 -- high level stuffing filter
  83 function stuff()
  84     return ltn12.filter.cycle(dot, 2)
  85 end