parsing accept header(s)

gistfile1.lua

-- @xxleite under [BeerWare] license

local string, io = require [[string]], require [[io]]

local gmatch, format, byte, write = string.gmatch, string.format, string.byte, io.write

-- common accept(s) content

local charsets = {
  '*', 'utf-8', 'utf-8, ISO-8859-1', 'utf-8;q=0.8, ISO-8859-1',
  'utf-8;q=0.8, ISO-8859-1', '*, utf-8;q=0', '*, utf-8'
}

local encodings = {
  'gzip', 'gzip, compress', 'deflate', '*', 'gzip, compress',
  'gzip;q=0.8, identity;q=0.5, *;q=0.3', 'gzip;q=0.8, compress',
  '*, compress;q=0', 'gzip;q=0.8, compress', '*, compress'
}

local languages = {
  'en', '*', 'en-US, en;q=0.8', 'en-US, en-GB', 'en;q=0.8, es',
  'en-US;q=0.8, es', '*, en;q=0', 'en-US;q=0.8, es', '*, en'
}

local media = {
  'text/html', '*/*', 'text/*', 'application/json, text/html', 'text/html;q=0.1',
  'application/json, text/html', 'application/json;q=0.2, text/html', 
  'application/json;q=0.2, text/html', 'text/*, text/html;q=0', 'text/*, text/html;q=0.5',
  'application/json, */*; q=0.01', 'application/vnd.example;attribute=value',
  'application/vnd.example;attribute=other', 'text/html;level=1', 'text/html;level=1;foo=bar',
  'text/html;level=2', 'text/html, text/html;level=1;q=0.1',
  'text/*;q=0.3, text/html;q=0.7, text/html;level=1, text/html;level=2;q=0.4, */*;q=0.5',
  'text/html, application/xhtml+xml, */*'
}

-- basic parsers

local function parse_one(str)
  for a, b, c, d in gmatch(str, '%s*([^%s-=;,]+)%s*([-=,]?)%s*([^%s;,]*)%s*(,?)') do
    write(format('\n  [%s]%s[%s]%s (%d)(%d)', a, b, c, d, byte(b) or 0, byte(d) or 0))
  end
end

local function parse_two(str)
  for a, b, c, d in gmatch(str, '%s*([^%s=;,]+)%s*([=,]?)%s*([^%s;,]*)%s*(,?)') do
    write(format('\n  [%s]%s[%s]%s (%d)(%d)', a, b, c, d, byte(b) or 0, byte(d) or 0))
  end
end

local function parse_three(str)
  for a, b, c, d in gmatch(str, '%s*([^/=%s]+)%s*([/=])%s*([^;,%s]+)%s*([;,]?)') do
    write(format('\n  [%s]%s[%s]%s (%d)(%d)', a, b, c, d, byte(b) or 0, byte(d) or 0))
  end
end

-- test all

for i=1, #charsets do
  write(charsets[i])
  parse_two(charsets[i])
  write('\n\n')
end

for i=1, #encodings do
  write(encodings[i])
  parse_two(encodings[i])
  write('\n\n')
end

for i=1, #languages do
  write(languages[i])
  parse_one(languages[i])
  write('\n\n')
end

for i=1, #media do
  write(media[i])
  parse_three(media[i])
  write('\n\n')
end