모듈:Yaml 문서 원본 보기

--[[
MIT License

Copyright (c) 2017 peposso

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
--]]

-------------------------------------------------------------------------------
-- tinyyaml - YAML subset parser
-------------------------------------------------------------------------------

local table = table
local string = string
local schar = string.char
local ssub, gsub = string.sub, string.gsub
local sfind, smatch = string.find, string.match
local tinsert, tremove = table.insert, table.remove
local setmetatable = setmetatable
local pairs = pairs
local type = type
local tonumber = tonumber
local math = math
local getmetatable = getmetatable
local error = error

local UNESCAPES = {
  ['0'] = "\x00", z = "\x00", N    = "\x85",
  a = "\x07",     b = "\x08", t    = "\x09",
  n = "\x0a",     v = "\x0b", f    = "\x0c",
  r = "\x0d",     e = "\x1b", ['\\'] = '\\',
};

-------------------------------------------------------------------------------
-- utils
local function select(list, pred)
  local selected = {}
  for i = 0, #list do
    local v = list[i]
    if v and pred(v, i) then
      tinsert(selected, v)
    end
  end
  return selected
end

local function startswith(haystack, needle)
  return ssub(haystack, 1, #needle) == needle
end

local function ltrim(str)
  return smatch(str, "^%s*(.-)$")
end

local function rtrim(str)
  return smatch(str, "^(.-)%s*$")
end

-------------------------------------------------------------------------------
-- Implementation.
--
local class = {__meta={}}
function class.__meta.__call(cls, ...)
  local self = setmetatable({}, cls)
  if cls.__init then
    cls.__init(self, ...)
  end
  return self
end

function class.def(base, typ, cls)
  base = base or class
  local mt = {__metatable=base, __index=base}
  for k, v in pairs(base.__meta) do mt[k] = v end
  cls = setmetatable(cls or {}, mt)
  cls.__index = cls
  cls.__metatable = cls
  cls.__type = typ
  cls.__meta = mt
  return cls
end


local types = {
  null = class:def('null'),
  map = class:def('map'),
  omap = class:def('omap'),
  pairs = class:def('pairs'),
  set = class:def('set'),
  seq = class:def('seq'),
  timestamp = class:def('timestamp'),
}

local Null = types.null
function Null.__tostring() return 'yaml.null' end
function Null.isnull(v)
  if v == nil then return true end
  if type(v) == 'table' and getmetatable(v) == Null then return true end
  return false
end
local null = Null()

function types.timestamp:__init(y, m, d, h, i, s, f, z)
  self.year = tonumber(y)
  self.month = tonumber(m)
  self.day = tonumber(d)
  self.hour = tonumber(h or 0)
  self.minute = tonumber(i or 0)
  self.second = tonumber(s or 0)
  if type(f) == 'string' and sfind(f, '^%d+$') then
    self.fraction = tonumber(f) * math.pow(10, 3 - #f)
  elseif f then
    self.fraction = f
  else
    self.fraction = 0
  end
  self.timezone = z
end

function types.timestamp:__tostring()
  return string.format(
    '%04d-%02d-%02dT%02d:%02d:%02d.%03d%s',
    self.year, self.month, self.day,
    self.hour, self.minute, self.second, self.fraction,
    self:gettz())
end

function types.timestamp:gettz()
  if not self.timezone then
    return ''
  end
  if self.timezone == 0 then
    return 'Z'
  end
  local sign = self.timezone > 0
  local z = sign and self.timezone or -self.timezone
  local zh = math.floor(z)
  local zi = (z - zh) * 60
  return string.format(
    '%s%02d:%02d', sign and '+' or '-', zh, zi)
end


local function countindent(line)
  local _, j = sfind(line, '^%s+')
  if not j then
    return 0, line
  end
  return j, ssub(line, j+1)
end

local function parsestring(line, stopper)
  stopper = stopper or ''
  local q = ssub(line, 1, 1)
  if q == ' ' or q == '\t' then
    return parsestring(ssub(line, 2))
  end
  if q == "'" then
    local i = sfind(line, "'", 2, true)
    if not i then
      return nil, line
    end
    return ssub(line, 2, i-1), ssub(line, i+1)
  end
  if q == '"' then
    local i, buf = 2, ''
    while i < #line do
      local c = ssub(line, i, i)
      if c == '\\' then
        local n = ssub(line, i+1, i+1)
        if UNESCAPES[n] ~= nil then
          buf = buf..UNESCAPES[n]
        elseif n == 'x' then
          local h = ssub(i+2,i+3)
          if sfind(h, '^[0-9a-fA-F]$') then
            buf = buf..schar(tonumber(h, 16))
            i = i + 2
          else
            buf = buf..'x'
          end
        else
          buf = buf..n
        end
        i = i + 1
      elseif c == q then
        break
      else
        buf = buf..c
      end
      i = i + 1
    end
    return buf, ssub(line, i+1)
  end
  if q == '{' or q == '[' then  -- flow style
    return nil, line
  end
  if q == '|' or q == '>' then  -- block
    return nil, line
  end
  if q == '-' or q == ':' then
    if ssub(line, 2, 2) == ' ' or #line == 1 then
      return nil, line
    end
  end
  local buf = ''
  while #line > 0 do
    local c = ssub(line, 1, 1)
    if sfind(stopper, c, 1, true) then
      break
    elseif c == ':' and (ssub(line, 2, 2) == ' ' or #line == 1) then
      break
    elseif c == '#' and (ssub(buf, #buf, #buf) == ' ') then
      break
    else
      buf = buf..c
    end
    line = ssub(line, 2)
  end
  return rtrim(buf), line
end

local function isemptyline(line)
  return line == '' or sfind(line, '^%s*$') or sfind(line, '^%s*#')
end

local function equalsline(line, needle)
  return startswith(line, needle) and isemptyline(ssub(line, #needle+1))
end

local function checkdupekey(map, key)
  if map[key] ~= nil then
    -- print("found a duplicate key '"..key.."' in line: "..line)
    local suffix = 1
    while map[key..'_'..suffix] do
      suffix = suffix + 1
    end
    key = key ..'_'..suffix
  end
  return key
end

local function parseflowstyle(line, lines)
  local stack = {}
  while true do
    if #line == 0 then
      if #lines == 0 then
        break
      else
        line = tremove(lines, 1)
      end
    end
    local c = ssub(line, 1, 1)
    if c == '#' then
      line = ''
    elseif c == ' ' or c == '\t' or c == '\r' or c == '\n' then
      line = ssub(line, 2)
    elseif c == '{' or c == '[' then
      tinsert(stack, {v={},t=c})
      line = ssub(line, 2)
    elseif c == ':' then
      local s = tremove(stack)
      tinsert(stack, {v=s.v, t=':'})
      line = ssub(line, 2)
    elseif c == ',' then
      local value = tremove(stack)
      if value.t == ':' or value.t == '{' or value.t == '[' then error() end
      if stack[#stack].t == ':' then
        -- map
        local key = tremove(stack)
        key.v = checkdupekey(stack[#stack].v, key.v)
        stack[#stack].v[key.v] = value.v
      elseif stack[#stack].t == '{' then
        -- set
        stack[#stack].v[value.v] = true
      elseif stack[#stack].t == '[' then
        -- seq
        tinsert(stack[#stack].v, value.v)
      end
      line = ssub(line, 2)
    elseif c == '}' then
      if stack[#stack].t == '{' then
        if #stack == 1 then break end
        stack[#stack].t = '}'
        line = ssub(line, 2)
      else
        line = ','..line
      end
    elseif c == ']' then
      if stack[#stack].t == '[' then
        if #stack == 1 then break end
        stack[#stack].t = ']'
        line = ssub(line, 2)
      else
        line = ','..line
      end
    else
      local s, rest = parsestring(line, ',{}[]')
      if not s then
        error('invalid flowstyle line: '..line)
      end
      tinsert(stack, {v=s, t='s'})
      line = rest
    end
  end
  return stack[1].v, line
end

local function parseblockstylestring(line, lines, indent)
  if #lines == 0 then
    error("failed to find multi-line scalar content")
  end
  local s = {}
  local firstindent = -1
  local endline = -1
  for i = 1, #lines do
    local ln = lines[i]
    local idt = countindent(ln)
    if idt <= indent then
      break
    end
    if ln == '' then
      tinsert(s, '')
    else
      if firstindent == -1 then
        firstindent = idt
      elseif idt < firstindent then
        break
      end
      tinsert(s, ssub(ln, firstindent + 1))
    end
    endline = i
  end

  local striptrailing = true
  local sep = '\n'
  local newlineatend = true
  if line == '|' then
    striptrailing = true
    sep = '\n'
    newlineatend = true
  elseif line == '|+' then
    striptrailing = false
    sep = '\n'
    newlineatend = true
  elseif line == '|-' then
    striptrailing = true
    sep = '\n'
    newlineatend = false
  elseif line == '>' then
    striptrailing = true
    sep = ' '
    newlineatend = true
  elseif line == '>+' then
    striptrailing = false
    sep = ' '
    newlineatend = true
  elseif line == '>-' then
    striptrailing = true
    sep = ' '
    newlineatend = false
  else
    error('invalid blockstyle string:'..line)
  end
  local eonl = 0
  for i = #s, 1, -1 do
    if s[i] == '' then
      tremove(s, i)
      eonl = eonl + 1
    end
  end
  if striptrailing then
    eonl = 0
  end
  if newlineatend then
    eonl = eonl + 1
  end
  for i = endline, 1, -1 do
    tremove(lines, i)
  end
  return table.concat(s, sep)..string.rep('\n', eonl)
end

local function parsetimestamp(line)
  local _, p1, y, m, d = sfind(line, '^(%d%d%d%d)%-(%d%d)%-(%d%d)')
  if not p1 then
    return nil, line
  end
  if p1 == #line then
    return types.timestamp(y, m, d), ''
  end
  local _, p2, h, i, s = sfind(line, '^[Tt ](%d+):(%d+):(%d+)', p1+1)
  if not p2 then
    return types.timestamp(y, m, d), ssub(line, p1+1)
  end
  if p2 == #line then
    return types.timestamp(y, m, d, h, i, s), ''
  end
  local _, p3, f = sfind(line, '^%.(%d+)', p2+1)
  if not p3 then
    p3 = p2
    f = 0
  end
  local zc = ssub(line, p3+1, p3+1)
  local _, p4, zs, z = sfind(line, '^ ?([%+%-])(%d+)', p3+1)
  if p4 then
    z = tonumber(z)
    local _, p5, zi = sfind(line, '^:(%d+)', p4+1)
    if p5 then
      z = z + tonumber(zi) / 60
    end
    z = zs == '-' and -tonumber(z) or tonumber(z)
  elseif zc == 'Z' then
    p4 = p3 + 1
    z = 0
  else
    p4 = p3
    z = false
  end
  return types.timestamp(y, m, d, h, i, s, f, z), ssub(line, p4+1)
end

local function parsescalar(line, lines, indent)
  line = ltrim(line)
  line = gsub(line, '^%s*#.*$', '')  -- comment only -> ''
  line = gsub(line, '^%s*', '')  -- trim head spaces

  if line == '' or line == '~' then
    return null
  end

  local ts, _ = parsetimestamp(line)
  if ts then
    return ts
  end

  local s, _ = parsestring(line)
  -- startswith quote ... string
  -- not startswith quote ... maybe string
  if s and (startswith(line, '"') or startswith(line, "'")) then
    return s
  end

  if startswith('!', line) then  -- unexpected tagchar
    error('unsupported line: '..line)
  end

  if equalsline(line, '{}') then
    return {}
  end
  if equalsline(line, '[]') then
    return {}
  end

  if startswith(line, '{') or startswith(line, '[') then
    return parseflowstyle(line, lines)
  end

  if startswith(line, '|') or startswith(line, '>') then
    return parseblockstylestring(line, lines, indent)
  end

  -- Regular unquoted string
  line = gsub(line, '%s*#.*$', '')  -- trim tail comment
  local v = line
  if v == 'null' or v == 'Null' or v == 'NULL'then
    return null
  elseif v == 'true' or v == 'True' or v == 'TRUE' then
    return true
  elseif v == 'false' or v == 'False' or v == 'FALSE' then
    return false
  elseif v == '.inf' or v == '.Inf' or v == '.INF' then
    return math.huge
  elseif v == '+.inf' or v == '+.Inf' or v == '+.INF' then
    return math.huge
  elseif v == '-.inf' or v == '-.Inf' or v == '-.INF' then
    return -math.huge
  elseif v == '.nan' or v == '.NaN' or v == '.NAN' then
    return 0 / 0
  elseif sfind(v, '^[%+%-]?[0-9]+$') or sfind(v, '^[%+%-]?[0-9]+%.$')then
    return tonumber(v)  -- : int
  elseif sfind(v, '^[%+%-]?[0-9]+%.[0-9]+$') then
    return tonumber(v)
  end
  return s or v
end

local parsemap;  -- : func

local function parseseq(line, lines, indent)
  local seq = setmetatable({}, types.seq)
  if line ~= '' then
    error()
  end
  while #lines > 0 do
    -- Check for a new document
    line = lines[1]
    if startswith(line, '---') then
      while #lines > 0 and not startswith(lines, '---') do
        tremove(lines, 1)
      end
      return seq
    end

    -- Check the indent level
    local level = countindent(line)
    if level < indent then
      return seq
    elseif level > indent then
      error("found bad indenting in line: ".. line)
    end

    local i, j = sfind(line, '%-%s+')
    if not i then
      i, j = sfind(line, '%-$')
      if not i then
        return seq
      end
    end
    local rest = ssub(line, j+1)

    if sfind(rest, '^[^\'\"%s]*:') then
      -- Inline nested hash
      local indent2 = j
      lines[1] = string.rep(' ', indent2)..rest
      tinsert(seq, parsemap('', lines, indent2))
    elseif sfind(rest, '^%-%s+') then
      -- Inline nested seq
      local indent2 = j
      lines[1] = string.rep(' ', indent2)..rest
      tinsert(seq, parseseq('', lines, indent2))
    elseif isemptyline(rest) then
      tremove(lines, 1)
      if #lines == 0 then
        tinsert(seq, null)
        return seq
      end
      if sfind(lines[1], '^%s*%-') then
        local nextline = lines[1]
        local indent2 = countindent(nextline)
        if indent2 == indent then
          -- Null seqay entry
          tinsert(seq, null)
        else
          tinsert(seq, parseseq('', lines, indent2))
        end
      else
        -- - # comment
        --   key: value
        local nextline = lines[1]
        local indent2 = countindent(nextline)
        tinsert(seq, parsemap('', lines, indent2))
      end
    elseif rest then
      -- Array entry with a value
      tremove(lines, 1)
      tinsert(seq, parsescalar(rest, lines))
    end
  end
  return seq
end

local function parseset(line, lines, indent)
  if not isemptyline(line) then
    error('not seq line: '..line)
  end
  local set = setmetatable({}, types.set)
  while #lines > 0 do
    -- Check for a new document
    line = lines[1]
    if startswith(line, '---') then
      while #lines > 0 and not startswith(lines, '---') do
        tremove(lines, 1)
      end
      return set
    end

    -- Check the indent level
    local level = countindent(line)
    if level < indent then
      return set
    elseif level > indent then
      error("found bad indenting in line: ".. line)
    end

    local i, j = sfind(line, '%?%s+')
    if not i then
      i, j = sfind(line, '%?$')
      if not i then
        return set
      end
    end
    local rest = ssub(line, j+1)

    if sfind(rest, '^[^\'\"%s]*:') then
      -- Inline nested hash
      local indent2 = j
      lines[1] = string.rep(' ', indent2)..rest
      set[parsemap('', lines, indent2)] = true
    elseif sfind(rest, '^%s+$') then
      tremove(lines, 1)
      if #lines == 0 then
        tinsert(set, null)
        return set
      end
      if sfind(lines[1], '^%s*%?') then
        local indent2 = countindent(lines[1])
        if indent2 == indent then
          -- Null array entry
          set[null] = true
        else
          set[parseseq('', lines, indent2)] = true
        end
      end

    elseif rest then
      tremove(lines, 1)
      set[parsescalar(rest, lines)] = true
    else
      error("failed to classify line: "..line)
    end
  end
  return set
end

function parsemap(line, lines, indent)
  if not isemptyline(line) then
    error('not map line: '..line)
  end
  local map = setmetatable({}, types.map)
  while #lines > 0 do
    -- Check for a new document
    line = lines[1]
    if startswith(line, '---') then
      while #lines > 0 and not startswith(lines, '---') do
        tremove(lines, 1)
      end
      return map
    end

    -- Check the indent level
    local level, _ = countindent(line)
    if level < indent then
      return map
    elseif level > indent then
      error("found bad indenting in line: ".. line)
    end

    -- Find the key
    local key
    local s, rest = parsestring(line)

    -- Quoted keys
    if s and startswith(rest, ':') then
      local sc = parsescalar(s, {}, 0)
      if sc and type(sc) ~= 'string' then
        key = sc
      else
        key = s
      end
      line = ssub(rest, 2)
    else
      error("failed to classify line: "..line)
    end

    key = checkdupekey(map, key)
    line = ltrim(line)

    if ssub(line, 1, 1) == '!' then
      -- ignore type
      local rh = ltrim(ssub(line, 3))
      local typename = smatch(rh, '^!?[^%s]+')
      line = ltrim(ssub(rh, #typename+1))
    end

    if not isemptyline(line) then
      tremove(lines, 1)
      line = ltrim(line)
      map[key] = parsescalar(line, lines, indent)
    else
      -- An indent
      tremove(lines, 1)
      if #lines == 0 then
        map[key] = null
        return map;
      end
      if sfind(lines[1], '^%s*%-') then
        local indent2 = countindent(lines[1])
        map[key] = parseseq('', lines, indent2)
      elseif sfind(lines[1], '^%s*%?') then
        local indent2 = countindent(lines[1])
        map[key] = parseset('', lines, indent2)
      else
        local indent2 = countindent(lines[1])
        if indent >= indent2 then
          -- Null hash entry
          map[key] = null
        else
          map[key] = parsemap('', lines, indent2)
        end
      end
    end
  end
  return map
end


-- : (list<str>)->dict
local function parsedocuments(lines)
  lines = select(lines, function(s) return not isemptyline(s) end)

  if sfind(lines[1], '^%%YAML') then tremove(lines, 1) end

  local root = {}
  local in_document = false
  while #lines > 0 do
    local line = lines[1]
    -- Do we have a document header?
    local docright;
    if sfind(line, '^%-%-%-') then
      -- Handle scalar documents
      docright = ssub(line, 4)
      tremove(lines, 1)
      in_document = true
    end
    if docright then
      if (not sfind(docright, '^%s+$') and
          not sfind(docright, '^%s+#')) then
        tinsert(root, parsescalar(docright, lines))
      end
    elseif #lines == 0 or startswith(line, '---') then
      -- A naked document
      tinsert(root, null)
      while #lines > 0 and not sfind(lines[1], '---') do
        tremove(lines, 1)
      end
      in_document = false
    -- XXX The final '-+$' is to look for -- which ends up being an
    -- error later.
    elseif not in_document and #root > 0 then
      -- only the first document can be explicit
      error('parse error: '..line)
    elseif sfind(line, '^%s*%-') then
      -- An array at the root
      tinsert(root, parseseq('', lines, 0))
    elseif sfind(line, '^%s*[^%s]') then
      -- A hash at the root
      local level = countindent(line)
      tinsert(root, parsemap('', lines, level))
    else
      -- Shouldn't get here.  @lines have whitespace-only lines
      -- stripped, and previous match is a line with any
      -- non-whitespace.  So this clause should only be reachable via
      -- a perlbug where \s is not symmetric with \S

      -- uncoverable statement
      error('parse error: '..line)
    end
  end
  if #root > 1 and Null.isnull(root[1]) then
    tremove(root, 1)
    return root
  end
  return root
end

--- Parse yaml string into table.
local function parse(source)
  local lines = {}
  for line in string.gmatch(source .. '\n', '(.-)\r?\n') do
    tinsert(lines, line)
  end

  local docs = parsedocuments(lines)
  if #docs == 1 then
    return docs[1]
  end

  return docs
end

p = {parse = parse}
return p