yamlvars (18jan22)

git-svn-id: svn://tug.org/texlive/trunk@61652 c570f23f-e606-0410-a88d-b1316a301751

3 files changed, 49 insertions, 840 deletions

diff --git a/Master/texmf-dist/tex/lualatex/yamlvars/YAMLvars.lua b/Master/texmf-dist/tex/lualatex/yamlvars/YAMLvars.lua
index 72e4d6ad1a4..93234e5d596 100644
--- a/Master/texmf-dist/tex/lualatex/yamlvars/YAMLvars.lua
+++ b/Master/texmf-dist/tex/lualatex/yamlvars/YAMLvars.lua
@@ -1,6 +1,6 @@
 --% Kale Ewasiuk (kalekje@gmail.com)
---% 2021-12-15
---% Copyright (C) 2021 Kale Ewasiuk
+--% 2022-01-18
+--% Copyright (C) 2021-2022 Kale Ewasiuk
 --%
 --% Permission is hereby granted, free of charge, to any person obtaining a copy
 --% of this software and associated documentation files (the "Software"), to deal
@@ -61,6 +61,7 @@ YAMLvars.dftDefault = nil
 YAMLvars.xfmDefault = {}
 
 YAMLvars.allowUndeclared = false
+YAMLvars.overwritedefs = false
 
 YAMLvars.valTemp = ''
 YAMLvars.varTemp = ''
@@ -69,7 +70,9 @@ YAMLvars.tabmidrule = 'hline'
 
 YAMLvars.debug = false
 
-YAMLvars.yaml = require('tinyyaml')
+YAMLvars.yaml = require'markdown-tinyyaml' -- note: YAMLvars.sty will have checked existence of this already
+local pl = _G['penlight'] or _G['pl'] -- penlight for this namespace is pl
+
 
 function YAMLvars.debugtalk(s, ss)
     if YAMLvars.debug then
@@ -77,9 +80,10 @@ function YAMLvars.debugtalk(s, ss)
     end
 end
 
+
 -- xfm functions (transforms) -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
 function YAMLvars.xfm.addxspace(var, val)
-    return val .. '\\xspace'
+    return val .. '\\xspace{}'
 end
 
 function YAMLvars.xfm.tab2arr(var, val)
@@ -99,10 +103,10 @@ function YAMLvars.xfm.arr2tabular(var, val)
 end
 
 
-function YAMLvars.xfm.arr2itemize(var, val)
+function YAMLvars.xfm.list2items(var, val) -- todo should be list2item
      return pl.List(val):map('\\item '.._1):join(' ')
 end
-
+YAMLvars.xfm.arr2itemize = YAMLvars.xfm.list2items
 
 function YAMLvars.xfm.arrsortAZ(var, val)
      return pl.List(val):sort(pl.operator.strlt)
@@ -126,12 +130,15 @@ function YAMLvars.xfm.arrsortlastnameAZ(var, val)
 end
 -- todo need distinction beyyween table and penlight list ???
 function YAMLvars.xfm.list2nl(var, val)
-    val = pl.array2d.map_slice1(_1..'\\\\', val, 1,-2)
-    return val:join('')
-    --return pl.tablex.reduce(_1.._2, val, '')
+    return pl.tablex.join(val,'\\\\ ')
 end
 
-function YAMLvars.xfm.lb2nl(var, val)
+    --val = pl.array2d.map_slice1(_1..'\\\\', val, 1,-2)
+    --return val:join('')
+    --return pl.tablex.reduce(_1.._2, val, '')
+
+
+function YAMLvars.xfm.lb2nl(var, val) --linebreak in text 2 new line
     val, _ = val:gsub('\n','\\\\ ')
     return val
 end
@@ -265,7 +272,7 @@ end
 
 
 function YAMLvars.prvcmd(cs, val) -- provide command via lua
-   if token.is_defined(cs) then
+   if token.is_defined(cs) and (not YAMLvars.overwritedefs) then
         tex.print('\\PackageError{YAMLvars}{Variable '..cs..' already defined, could not declare}{}')
     else
         token.set_macro(cs, val, 'global')
@@ -339,21 +346,29 @@ local function sub_lua_var(s, v1, v2)
     return s:gsub('([%A?%-?])('..v1..')([%W?%-?])', '%1'..v2..'%3') -- replace x variables
 end
 
+local _YV_invalid_expression = '\1 invalid expression'
+local _YV_no_return = '\2 no return val'
 local function eval_expr(func, var, val)
-    local s, c = func:gsub('^[=/]', {['/'] = '', ['='] = 'YAMLvars.valTemp = '}, 1) -- / is run code, = sets val = code
+    local s, c = func:gsub('^[=/]', {['/'] = '\2', ['='] = 'YAMLvars.valTemp = '}, 1) -- / is run code, = sets val = code
     if c == 0 then
-        return nil
+        return _YV_invalid_expression
     else
         --help_wrt(s, var)
         --help_wrt(val, var)
         YAMLvars.valTemp = val
         YAMLvars.varTemp = var
         --help_wrt(s, var)
+        s, c = s:gsub('\2', '') -- strip \2 that might have appeared if / was applied
         s = sub_lua_var(' '..s, 'x', 'YAMLvars.valTemp')
         s = sub_lua_var(s, 'v', 'YAMLvars.varTemp')
         --help_wrt(s, var)
-        loadstring(s)()
-        --help_wrt(val, var)
+        local f, err = pcall(loadstring(s))
+        if not f then
+            tex.print('\\PackageError{YAMLvars}{xfm with "= or /" error on var "'..var..'"}{}') --
+        end
+        if c > 0 then
+            return _YV_no_return
+        end
         return YAMLvars.valTemp
     end
 end
@@ -363,8 +378,9 @@ local function transform_and_prc(var, val)
         local f = YAMLvars.xfm[func]
         if f == nil then
             local val2 =  eval_expr(func, var, val)
-            if val2 == nil then
-                tex.print('\\PackageWarning{YAMLvars}{xfm function "'..func..'" not defined, skipping}{}')
+            if val2 == _YV_invalid_expression then
+                tex.print('\\PackageError{YAMLvars}{xfm function "'..func..'" not defined or invalid expression passed on var "'..var..'"}{}')
+            elseif val == _YV_no_return then
             else
                 val = val2
             end
@@ -374,7 +390,7 @@ local function transform_and_prc(var, val)
     end
     f = YAMLvars.prc[YAMLvars.varspecs[var]['prc']]
     if f == nil then
-        tex.print('\\PackageError{YAMLvars}{prc function "'..YAMLvars.varspecs[var]['prc']..'" not defined}{}')
+        tex.print('\\PackageError{YAMLvars}{prc function "'..YAMLvars.varspecs[var]['prc']..'" on var "'..var..'" not defined}{}')
     end
     f(var, val) -- prc the value of the variable
 end
@@ -383,7 +399,10 @@ function YAMLvars.parseYAMLvarsStr(y)
     YAMLvars.varsvals = YAMLvars.yaml.parse(y)
     for var, val in pairs(YAMLvars.varsvals) do
         if YAMLvars.varspecs[var] == nil then
-            check_def(var, val)
+            check_def(var, val) -- if not declared
+            -- todo consider free form parse declaring
+            -- variable name: {xfm:, dec:, prc:, val: }
+            -- definitely doable here
         else
             transform_and_prc(var, val)
         end
diff --git a/Master/texmf-dist/tex/lualatex/yamlvars/YAMLvars.sty b/Master/texmf-dist/tex/lualatex/yamlvars/YAMLvars.sty
index 23928006519..73c40ba6931 100644
--- a/Master/texmf-dist/tex/lualatex/yamlvars/YAMLvars.sty
+++ b/Master/texmf-dist/tex/lualatex/yamlvars/YAMLvars.sty
@@ -1,6 +1,6 @@
 % Kale Ewasiuk (kalekje@gmail.com)
-% 2021-12-15
-% Copyright (C) 2021 Kale Ewasiuk
+% 2022-01-18
+% Copyright (C) 2021-2022 Kale Ewasiuk
 %
 % Permission is hereby granted, free of charge, to any person obtaining a copy
 % of this software and associated documentation files (the "Software"), to deal
@@ -23,15 +23,17 @@
 % OR OTHER DEALINGS IN THE SOFTWARE.
 
 
+
 \NeedsTeXFormat{LaTeX2e}
-\ProvidesPackage{YAMLvars}[2021-12-15]
+\ProvidesPackage{YAMLvars}[2022-01-18]
+
+\IfFileExists{markdown-tinyyaml.lua}{}{\PackageError{YAMLvars}{This package requires installation of the 'markdown' package, please install it and try again}{}}
 
 \RequirePackage{luacode}
 \RequirePackage{xspace}
 \RequirePackage{etoolbox}
 \RequirePackage[pl,extras]{penlight}
 
-
 \luadirect{YAMLvars = require('YAMLvars')}
 
 \DeclareOption{useyv}{
@@ -43,7 +45,11 @@
 }
 \DeclareOption{allowundeclared}{
         \luadirect{YAMLvars.allowUndeclared = true}
-}\DeclareOption{debug}{
+}
+\DeclareOption{overwritedefs}{
+        \luadirect{YAMLvars.overwritedefs = true}
+}
+\DeclareOption{debug}{
         \luadirect{YAMLvars.debug = true}
 }
 
diff --git a/Master/texmf-dist/tex/lualatex/yamlvars/tinyyaml.lua b/Master/texmf-dist/tex/lualatex/yamlvars/tinyyaml.lua
deleted file mode 100644
index b1a64708635..00000000000
--- a/Master/texmf-dist/tex/lualatex/yamlvars/tinyyaml.lua
+++ /dev/null
@@ -1,816 +0,0 @@
--------------------------------------------------------------------------------
--- 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, tconcat, tremove = table.insert, table.concat, 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
-
-local function trim(str)
-  return smatch(str, "^%s*(.-)%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]$') then
-            buf = buf..schar(tonumber(h, 16))
-            i = i + 2
-          else
-            buf = buf..'x'
-          end
-        else
-          buf = buf..n
-        end
-        i = i + 1
-      elseif c == q then
-        break
-      else
-        buf = buf..c
-      end
-      i = i + 1
-    end
-    return buf, ssub(line, i+1)
-  end
-  if q == '{' or q == '[' then  -- flow style
-    return nil, line
-  end
-  if q == '|' or q == '>' then  -- block
-    return nil, line
-  end
-  if q == '-' or q == ':' then
-    if ssub(line, 2, 2) == ' ' or ssub(line, 2, 2) == '\n' or #line == 1 then
-      return nil, line
-    end
-  end
-  local buf = ''
-  while #line > 0 do
-    local c = ssub(line, 1, 1)
-    if sfind(stopper, c, 1, true) then
-      break
-    elseif c == ':' and (ssub(line, 2, 2) == ' ' or ssub(line, 2, 2) == '\n' or #line == 1) then
-      break
-    elseif c == '#' and (ssub(buf, #buf, #buf) == ' ') then
-      break
-    else
-      buf = buf..c
-    end
-    line = ssub(line, 2)
-  end
-  return rtrim(buf), line
-end
-
-local function isemptyline(line)
-  return line == '' or sfind(line, '^%s*$') or sfind(line, '^%s*#')
-end
-
-local function equalsline(line, needle)
-  return startswith(line, needle) and isemptyline(ssub(line, #needle+1))
-end
-
-local function compactifyemptylines(lines)
-  -- Appends empty lines as "\n" to the end of the nearest preceding non-empty line
-  local compactified = {}
-  local lastline = {}
-  for i = 1, #lines do
-    local line = lines[i]
-    if isemptyline(line) then
-      if #compactified > 0 and i < #lines then
-        tinsert(lastline, "\n")
-      end
-    else
-      if #lastline > 0 then
-        tinsert(compactified, tconcat(lastline, ""))
-      end
-      lastline = {line}
-    end
-  end
-  if #lastline > 0 then
-    tinsert(compactified, tconcat(lastline, ""))
-  end
-  return compactified
-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 = s[#s]:gsub('\n', '\n')
-  s[#s] = rtrim(s[#s])
-  if striptrailing then
-    eonl = 0
-  end
-  if newlineatend then
-    eonl = eonl + 1
-  end
-  for i = endline, 1, -1 do
-    tremove(lines, i)
-  end
-  return tconcat(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 = trim(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]*:%s*$') or sfind(rest, '^[^\'\"%s]*:%s+.') then
-      -- Inline nested hash
-      -- There are two patterns need to match as inline nested hash
-      --   first one should have no other characters except whitespace after `:`
-      --   and the second one should have characters besides whitespace after `:`
-      --
-      --  value:
-      --    - foo:
-      --        bar: 1
-      --
-      -- and
-      --
-      --  value:
-      --    - foo: bar
-      --
-      -- And there is one pattern should not be matched, where there is no space after `:`
-      --   in below, `foo:bar` should be parsed into a single string
-      --
-      -- value:
-      --   - foo:bar
-      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 = compactifyemptylines(lines)
-
-  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
-
-return {
-  version = 0.1,
-  parse = parse,
-}