path: root/nomsu_compiler.lua

local lpeg = require('lpeg')
local re = require('re')
local utils = require('utils')
local Files = require('files')
local repr, stringify, equivalent
repr, stringify, equivalent = utils.repr, utils.stringify, utils.equivalent
colors = require('consolecolors')
colored = setmetatable({ }, {
  __index = function(_, color)
    return (function(msg)
      return colors[color] .. tostring(msg or '') .. colors.reset
    end)
  end
})
local insert, remove, concat
do
  local _obj_0 = table
  insert, remove, concat = _obj_0.insert, _obj_0.remove, _obj_0.concat
end
local unpack = unpack or table.unpack
local match, sub, gsub, format, byte, find
do
  local _obj_0 = string
  match, sub, gsub, format, byte, find = _obj_0.match, _obj_0.sub, _obj_0.gsub, _obj_0.format, _obj_0.byte, _obj_0.find
end
local NomsuCode, LuaCode, Source
do
  local _obj_0 = require("code_obj")
  NomsuCode, LuaCode, Source = _obj_0.NomsuCode, _obj_0.LuaCode, _obj_0.Source
end
local AST = require("syntax_tree")
local Parser = require("parser")
SOURCE_MAP = { }
string.as_lua_id = function(str)
  local argnum = 0
  str = gsub(str, "x([0-9A-F][0-9A-F])", "x\0%1")
  str = gsub(str, "%W", function(c)
    if c == ' ' then
      return '_'
    elseif c == '%' then
      argnum = argnum + 1
      return tostring(argnum)
    else
      return format("x%02X", byte(c))
    end
  end)
  return '_' .. str
end
table.map = function(self, fn)
  local _accum_0 = { }
  local _len_0 = 1
  for _, v in ipairs(self) do
    _accum_0[_len_0] = fn(v)
    _len_0 = _len_0 + 1
  end
  return _accum_0
end
table.fork = function(t, values)
  return setmetatable(values or { }, {
    __index = t
  })
end
do
  local STRING_METATABLE = getmetatable("")
  STRING_METATABLE.__add = function(self, other)
    return self .. stringify(other)
  end
  STRING_METATABLE.__index = function(self, i)
    local ret = string[i]
    if ret ~= nil then
      return ret
    end
    if type(i) == 'number' then
      return sub(self, i, i)
    elseif type(i) == 'table' then
      return sub(self, i[1], i[2])
    end
  end
end
local _list_mt = {
  __eq = equivalent,
  __tostring = function(self)
    return "[" .. concat((function()
      local _accum_0 = { }
      local _len_0 = 1
      for _index_0 = 1, #self do
        local b = self[_index_0]
        _accum_0[_len_0] = repr(b)
        _len_0 = _len_0 + 1
      end
      return _accum_0
    end)(), ", ") .. "]"
  end,
  __lt = function(self, other)
    assert(type(self) == 'table' and type(other) == 'table', "Incompatible types for comparison")
    for i = 1, math.max(#self, #other) do
      if not self[i] and other[i] then
        return true
      elseif self[i] and not other[i] then
        return false
      elseif self[i] < other[i] then
        return true
      elseif self[i] > other[i] then
        return false
      end
    end
    return false
  end,
  __le = function(self, other)
    assert(type(self) == 'table' and type(other) == 'table', "Incompatible types for comparison")
    for i = 1, math.max(#self, #other) do
      if not self[i] and other[i] then
        return true
      elseif self[i] and not other[i] then
        return false
      elseif self[i] < other[i] then
        return true
      elseif self[i] > other[i] then
        return false
      end
    end
    return true
  end
}
local list
list = function(t)
  return setmetatable(t, _list_mt)
end
local _dict_mt = {
  __eq = equivalent,
  __tostring = function(self)
    return "{" .. concat((function()
      local _accum_0 = { }
      local _len_0 = 1
      for k, v in pairs(self) do
        _accum_0[_len_0] = tostring(repr(k)) .. ": " .. tostring(repr(v))
        _len_0 = _len_0 + 1
      end
      return _accum_0
    end)(), ", ") .. "}"
  end
}
local dict
dict = function(t)
  return setmetatable(t, _dict_mt)
end
local MAX_LINE = 80
local NomsuCompiler = setmetatable({ }, {
  __index = function(self, k)
    do
      local _self = rawget(self, "self")
      if _self then
        return _self[k]
      else
        return nil
      end
    end
  end
})
do
  NomsuCompiler.NOMSU_COMPILER_VERSION = 4
  NomsuCompiler.NOMSU_SYNTAX_VERSION = Parser.version
  NomsuCompiler._ENV = NomsuCompiler
  NomsuCompiler.nomsu = NomsuCompiler
  NomsuCompiler.parse = function(self, ...)
    return Parser.parse(...)
  end
  NomsuCompiler.can_optimize = function()
    return false
  end
  local to_add = {
    repr = repr,
    stringify = stringify,
    utils = utils,
    lpeg = lpeg,
    re = re,
    Files = Files,
    next = next,
    unpack = unpack,
    setmetatable = setmetatable,
    coroutine = coroutine,
    rawequal = rawequal,
    getmetatable = getmetatable,
    pcall = pcall,
    error = error,
    package = package,
    os = os,
    require = require,
    tonumber = tonumber,
    tostring = tostring,
    string = string,
    xpcall = xpcall,
    module = module,
    print = print,
    loadfile = loadfile,
    rawset = rawset,
    _VERSION = _VERSION,
    collectgarbage = collectgarbage,
    rawget = rawget,
    rawlen = rawlen,
    table = table,
    assert = assert,
    dofile = dofile,
    loadstring = loadstring,
    type = type,
    select = select,
    debug = debug,
    math = math,
    io = io,
    load = load,
    pairs = pairs,
    ipairs = ipairs,
    list = list,
    dict = dict
  }
  for k, v in pairs(to_add) do
    NomsuCompiler[k] = v
  end
  for k, v in pairs(AST) do
    NomsuCompiler[k] = v
  end
  NomsuCompiler.LuaCode = LuaCode
  NomsuCompiler.NomsuCode = NomsuCode
  NomsuCompiler.Source = Source
  NomsuCompiler.ALIASES = setmetatable({ }, {
    __mode = "k"
  })
  NomsuCompiler.LOADED = { }
  NomsuCompiler.TESTS = { }
  NomsuCompiler.AST = AST
  NomsuCompiler.compile_error = function(self, source, err_format_string, ...)
    err_format_string = err_format_string:gsub("%%[^s]", "%%%1")
    local file = Files.read(source.filename)
    local line_starts = Files.get_line_starts(file)
    local line_no = Files.get_line_number(file, source.start)
    local line_start = line_starts[line_no]
    local src = colored.dim(file:sub(line_start, source.start - 1))
    src = src .. colored.underscore(colored.bright(colored.red(file:sub(source.start, source.stop - 1))))
    local end_of_line = (line_starts[Files.get_line_number(file, source.stop) + 1] or 0) - 1
    src = src .. colored.dim(file:sub(source.stop, end_of_line - 1))
    src = '    ' .. src:gsub('\n', '\n    ')
    local err_msg = err_format_string:format(src, ...)
    return error(tostring(source.filename) .. ":" .. tostring(line_no) .. ": " .. err_msg, 0)
  end
  local math_expression = re.compile([[ ([+-] " ")* "%" (" " [*/^+-] (" " [+-])* " %")+ !. ]])
  local add_lua_bits
  add_lua_bits = function(self, val_or_stmt, code)
    local cls = val_or_stmt == "value" and LuaCode.Value or LuaCode
    local operate_on_text
    operate_on_text = function(text)
      local lua = cls(text.source)
      for _index_0 = 1, #text do
        local bit = text[_index_0]
        if type(bit) == "string" then
          lua:append(bit)
        elseif bit.type == "Text" then
          lua:append(operate_on_text(bit))
        else
          local bit_lua = self:compile(bit)
          if not (bit_lua.is_value) then
            self:compile_error(bit.source, "Cannot use:\n%s\nas a string interpolation value, since it's not an expression.")
          end
          lua:append(bit_lua)
        end
      end
      return lua
    end
    return operate_on_text(code)
  end
  local add_lua_string_bits
  add_lua_string_bits = function(self, val_or_stmt, code)
    local cls_str = val_or_stmt == "value" and "LuaCode.Value(" or "LuaCode("
    if code.type ~= "Text" then
      return LuaCode.Value(code.source, cls_str, repr(tostring(code.source)), ", ", self:compile(code), ")")
    end
    local add_bit_lua
    add_bit_lua = function(lua, bit_lua)
      local bit_leading_len = #(tostring(bit_lua):match("^[^\n]*"))
      lua:append(lua:trailing_line_len() + bit_leading_len > MAX_LINE and ",\n    " or ", ")
      return lua:append(bit_lua)
    end
    local operate_on_text
    operate_on_text = function(text)
      local lua = LuaCode.Value(text.source, cls_str, repr(tostring(text.source)))
      for _index_0 = 1, #text do
        local bit = text[_index_0]
        if type(bit) == "string" then
          add_bit_lua(lua, repr(bit))
        elseif bit.type == "Text" then
          add_bit_lua(lua, operate_on_text(bit))
        else
          local bit_lua = self:compile(bit)
          if not (bit_lua.is_value) then
            self:compile_error(bit.source, "Cannot use:\n%s\nas a string interpolation value, since it's not an expression.")
          end
          add_bit_lua(lua, bit_lua)
        end
      end
      lua:append(")")
      return lua
    end
    return operate_on_text(code)
  end
  NomsuCompiler.COMPILE_ACTIONS = setmetatable({
    ["# compile math expr #"] = function(self, tree, ...)
      local lua = LuaCode.Value(tree.source)
      for i, tok in ipairs(tree) do
        if type(tok) == 'string' then
          lua:append(tok)
        else
          local tok_lua = self:compile(tok)
          if not (tok_lua.is_value) then
            self:compile_error(tok.source, "Non-expression value inside math expression:\n%s")
          end
          if tok.type == "Action" then
            tok_lua:parenthesize()
          end
          lua:append(tok_lua)
        end
        if i < #tree then
          lua:append(" ")
        end
      end
      return lua
    end,
    ["Lua %"] = function(self, tree, _code)
      return add_lua_string_bits(self, 'statements', _code)
    end,
    ["Lua value %"] = function(self, tree, _code)
      return add_lua_string_bits(self, 'value', _code)
    end,
    ["lua > %"] = function(self, tree, _code)
      if _code.type ~= "Text" then
        return LuaCode(tree.source, "nomsu:run_lua(", self:compile(_code), ");")
      end
      return add_lua_bits(self, "statements", _code)
    end,
    ["= lua %"] = function(self, tree, _code)
      if _code.type ~= "Text" then
        return LuaCode.Value(tree.source, "nomsu:run_lua(", self:compile(_code), ":as_statements('return '))")
      end
      return add_lua_bits(self, "value", _code)
    end,
    ["use %"] = function(self, tree, _path)
      if _path.type == 'Text' and #_path == 1 and type(_path[1]) == 'string' then
        local path = _path[1]
        for _, f in Files.walk(path) do
          self:run_file(f)
        end
      end
      return LuaCode(tree.source, "for i,f in Files.walk(", self:compile(_path), ") do nomsu:run_file(f) end")
    end,
    ["tests"] = function(self, tree)
      return LuaCode.Value(tree.source, "TESTS")
    end,
    ["test %"] = function(self, tree, _body)
      local test_str = table.concat((function()
        local _accum_0 = { }
        local _len_0 = 1
        for _index_0 = 1, #_body do
          local line = _body[_index_0]
          _accum_0[_len_0] = tostring(self:tree_to_nomsu(line))
          _len_0 = _len_0 + 1
        end
        return _accum_0
      end)(), "\n")
      return LuaCode(tree.source, "TESTS[" .. tostring(repr(tostring(tree.source))) .. "] = ", repr(test_str))
    end
  }, {
    __index = function(self, stub)
      if math_expression:match(stub) then
        return self["# compile math expr #"]
      end
    end
  })
  NomsuCompiler.run = function(self, to_run, source, version)
    if source == nil then
      source = nil
    end
    if version == nil then
      version = nil
    end
    source = source or (to_run.source or Source(to_run, 1, #to_run))
    if type(source) == 'string' then
      source = Source:from_string(source)
    end
    if not Files.read(source.filename) then
      Files.spoof(source.filename, to_run)
    end
    local tree
    if AST.is_syntax_tree(to_run) then
      tree = to_run
    else
      tree = self:parse(to_run, source, version)
    end
    if tree == nil then
      return nil
    end
    if tree.type ~= "FileChunks" then
      tree = {
        tree
      }
    end
    local ret = nil
    local all_lua = { }
    for _index_0 = 1, #tree do
      local chunk = tree[_index_0]
      local lua = self:compile(chunk):as_statements("return ")
      lua:declare_locals()
      lua:prepend("-- File: " .. tostring(source.filename:gsub("\n.*", "...")) .. "\n")
      insert(all_lua, tostring(lua))
      ret = self:run_lua(lua)
    end
    return ret
  end
  local _running_files = { }
  NomsuCompiler.run_file = function(self, filename)
    if self.LOADED[filename] then
      return self.LOADED[filename]
    end
    for i, running in ipairs(_running_files) do
      if running == filename then
        local loop
        do
          local _accum_0 = { }
          local _len_0 = 1
          for j = i, #_running_files do
            _accum_0[_len_0] = _running_files[j]
            _len_0 = _len_0 + 1
          end
          loop = _accum_0
        end
        insert(loop, filename)
        error("Circular import, this loops forever: " .. tostring(concat(loop, " -> ")) .. "...")
      end
    end
    insert(_running_files, filename)
    local ret = nil
    if match(filename, "%.lua$") then
      local file = assert(Files.read(filename), "Could not find file: " .. tostring(filename))
      ret = self:run_lua(file, Source(filename, 1, #file))
    elseif match(filename, "%.nom$") or match(filename, "^/dev/fd/[012]$") then
      local ran_lua
      if self.can_optimize(filename) then
        local lua_filename = gsub(filename, "%.nom$", ".lua")
        do
          local file = Files.read(lua_filename)
          if file then
            ret = self:run_lua(file, Source(lua_filename, 1, #file))
            ran_lua = true
          end
        end
      end
      if not (ran_lua) then
        local file = Files.read(filename)
        if not file then
          error("File does not exist: " .. tostring(filename), 0)
        end
        ret = self:run(file, Source(filename, 1, #file))
      end
    else
      error("Invalid filetype for " .. tostring(filename), 0)
    end
    self.LOADED[filename] = ret or true
    remove(_running_files)
    self.LOADED[filename] = ret or true
    return ret
  end
  NomsuCompiler.run_lua = function(self, lua, source)
    if source == nil then
      source = nil
    end
    local lua_string = tostring(lua)
    local run_lua_fn, err = load(lua_string, nil and tostring(source or lua.source), "t", self)
    if not run_lua_fn then
      local line_numbered_lua = concat((function()
        local _accum_0 = { }
        local _len_0 = 1
        for i, line in ipairs(Files.get_lines(lua_string)) do
          _accum_0[_len_0] = format("%3d|%s", i, line)
          _len_0 = _len_0 + 1
        end
        return _accum_0
      end)(), "\n")
      error("Failed to compile generated code:\n" .. tostring(colored.bright(colored.blue(colored.onblack(line_numbered_lua)))) .. "\n\n" .. tostring(err), 0)
    end
    source = source or lua.source
    local source_key = tostring(source)
    if not (SOURCE_MAP[source_key]) then
      local map = { }
      local file = Files.read(source.filename)
      if not file then
        error("Failed to find file: " .. tostring(source.filename))
      end
      local nomsu_str = tostring(file:sub(source.start, source.stop))
      local lua_line = 1
      local nomsu_line = Files.get_line_number(file, source.start)
      local map_sources
      map_sources = function(s)
        if type(s) == 'string' then
          for nl in s:gmatch("\n") do
            map[lua_line] = map[lua_line] or nomsu_line
            lua_line = lua_line + 1
          end
        else
          if s.source and s.source.filename == source.filename then
            nomsu_line = Files.get_line_number(file, s.source.start)
          end
          local _list_0 = s.bits
          for _index_0 = 1, #_list_0 do
            local b = _list_0[_index_0]
            map_sources(b)
          end
        end
      end
      map_sources(lua)
      map[lua_line] = map[lua_line] or nomsu_line
      map[0] = 0
      SOURCE_MAP[source_key] = map
    end
    return run_lua_fn()
  end
  NomsuCompiler.compile = function(self, tree)
    if tree.version then
      do
        local get_version = self['A' .. string.as_lua_id("Nomsu version")]
        if get_version then
          do
            local upgrade = self['A' .. string.as_lua_id("1 upgraded from 2 to 3")]
            if upgrade then
              tree = upgrade(tree, tree.version, get_version())
            end
          end
        end
      end
    end
    local _exp_0 = tree.type
    if "Action" == _exp_0 then
      local stub = tree.stub
      do
        local compile_action = self.COMPILE_ACTIONS[stub]
        if compile_action then
          local args
          do
            local _accum_0 = { }
            local _len_0 = 1
            for _index_0 = 1, #tree do
              local arg = tree[_index_0]
              if type(arg) ~= "string" then
                _accum_0[_len_0] = arg
                _len_0 = _len_0 + 1
              end
            end
            args = _accum_0
          end
          local ret = compile_action(self, tree, unpack(args))
          if not ret then
            self:compile_error(tree.source, "Compile-time action:\n%s\nfailed to produce any Lua")
          end
          return ret
        end
      end
      local lua = LuaCode.Value(tree.source, "A", string.as_lua_id(stub), "(")
      local args = { }
      for i, tok in ipairs(tree) do
        local _continue_0 = false
        repeat
          if type(tok) == "string" then
            _continue_0 = true
            break
          end
          local arg_lua = self:compile(tok)
          if not (arg_lua.is_value) then
            self:compile_error(tok.source, "Cannot use:\n%s\nas an argument to %s, since it's not an expression, it produces: %s", stub, repr(arg_lua))
          end
          insert(args, arg_lua)
          _continue_0 = true
        until true
        if not _continue_0 then
          break
        end
      end
      lua:concat_append(args, ", ")
      lua:append(")")
      return lua
    elseif "EscapedNomsu" == _exp_0 then
      local make_tree
      make_tree = function(t)
        if not (AST.is_syntax_tree(t)) then
          return repr(t)
        end
        local bits
        do
          local _accum_0 = { }
          local _len_0 = 1
          for _index_0 = 1, #t do
            local bit = t[_index_0]
            _accum_0[_len_0] = make_tree(bit)
            _len_0 = _len_0 + 1
          end
          bits = _accum_0
        end
        insert(bits, 1, repr(tostring(t.source)))
        return t.type .. "(" .. concat(bits, ", ") .. ")"
      end
      return LuaCode.Value(tree.source, make_tree(tree[1]))
    elseif "Block" == _exp_0 then
      local lua = LuaCode(tree.source)
      lua:concat_append((function()
        local _accum_0 = { }
        local _len_0 = 1
        for _index_0 = 1, #tree do
          local line = tree[_index_0]
          _accum_0[_len_0] = self:compile(line):as_statements()
          _len_0 = _len_0 + 1
        end
        return _accum_0
      end)(), "\n")
      return lua
    elseif "Text" == _exp_0 then
      local lua = LuaCode.Value(tree.source)
      local string_buffer = ""
      for i, bit in ipairs(tree) do
        local _continue_0 = false
        repeat
          if type(bit) == "string" then
            string_buffer = string_buffer .. bit
            _continue_0 = true
            break
          end
          if string_buffer ~= "" then
            if #lua.bits > 0 then
              lua:append("..")
            end
            lua:append(repr(string_buffer))
            string_buffer = ""
          end
          local bit_lua = self:compile(bit)
          if not (bit_lua.is_value) then
            local src = '    ' .. gsub(tostring(recurse(bit)), '\n', '\n    ')
            local line = tostring(bit.source.filename) .. ":" .. tostring(Files.get_line_number(Files.read(bit.source.filename), bit.source.start))
            self:compile_error(bit.source, "Cannot use:\n%s\nas a string interpolation value, since it's not an expression.")
          end
          if #lua.bits > 0 then
            lua:append("..")
          end
          if bit.type ~= "Text" then
            bit_lua = LuaCode.Value(bit.source, "stringify(", bit_lua, ")")
          end
          lua:append(bit_lua)
          _continue_0 = true
        until true
        if not _continue_0 then
          break
        end
      end
      if string_buffer ~= "" or #lua.bits == 0 then
        if #lua.bits > 0 then
          lua:append("..")
        end
        lua:append(repr(string_buffer))
      end
      if #lua.bits > 1 then
        lua:parenthesize()
      end
      return lua
    elseif "List" == _exp_0 then
      local lua = LuaCode.Value(tree.source, "list{")
      lua:concat_append((function()
        local _accum_0 = { }
        local _len_0 = 1
        for _index_0 = 1, #tree do
          local e = tree[_index_0]
          _accum_0[_len_0] = self:compile(e)
          _len_0 = _len_0 + 1
        end
        return _accum_0
      end)(), ", ", ",\n  ")
      lua:append("}")
      return lua
    elseif "Dict" == _exp_0 then
      local lua = LuaCode.Value(tree.source, "dict{")
      lua:concat_append((function()
        local _accum_0 = { }
        local _len_0 = 1
        for _index_0 = 1, #tree do
          local e = tree[_index_0]
          _accum_0[_len_0] = self:compile(e)
          _len_0 = _len_0 + 1
        end
        return _accum_0
      end)(), ", ", ",\n  ")
      lua:append("}")
      return lua
    elseif "DictEntry" == _exp_0 then
      local key, value = tree[1], tree[2]
      local key_lua = self:compile(key)
      if not (key_lua.is_value) then
        self:compile_error(tree[1].source, "Cannot use:\n%s\nas a dict key, since it's not an expression.")
      end
      local value_lua = value and self:compile(value) or LuaCode.Value(key.source, "true")
      if not (value_lua.is_value) then
        self:compile_error(tree[2].source, "Cannot use:\n%s\nas a dict value, since it's not an expression.")
      end
      local key_str = match(tostring(key_lua), [=[["']([a-zA-Z_][a-zA-Z0-9_]*)['"]]=])
      if key_str then
        return LuaCode(tree.source, key_str, "=", value_lua)
      elseif sub(tostring(key_lua), 1, 1) == "[" then
        return LuaCode(tree.source, "[ ", key_lua, "]=", value_lua)
      else
        return LuaCode(tree.source, "[", key_lua, "]=", value_lua)
      end
    elseif "IndexChain" == _exp_0 then
      local lua = self:compile(tree[1])
      if not (lua.is_value) then
        self:compile_error(tree[1].source, "Cannot index:\n%s\nsince it's not an expression.")
      end
      local first_char = sub(tostring(lua), 1, 1)
      if first_char == "{" or first_char == '"' or first_char == "[" then
        lua:parenthesize()
      end
      for i = 2, #tree do
        local key = tree[i]
        local key_lua = self:compile(key)
        if not (key_lua.is_value) then
          self:compile_error(key.source, "Cannot use:\n%s\nas an index, since it's not an expression.")
        end
        local key_lua_str = tostring(key_lua)
        do
          local lua_id = match(key_lua_str, "^['\"]([a-zA-Z_][a-zA-Z0-9_]*)['\"]$")
          if lua_id then
            lua:append("." .. tostring(lua_id))
          elseif sub(key_lua_str, 1, 1) == '[' then
            lua:append("[ ", key_lua, " ]")
          else
            lua:append("[", key_lua, "]")
          end
        end
      end
      return lua
    elseif "Number" == _exp_0 then
      return LuaCode.Value(tree.source, tostring(tree[1]))
    elseif "Var" == _exp_0 then
      return LuaCode.Value(tree.source, string.as_lua_id(tree[1]))
    elseif "FileChunks" == _exp_0 then
      return error("Cannot convert FileChunks to a single block of lua, since each chunk's " .. "compilation depends on the earlier chunks")
    else
      return error("Unknown type: " .. tostring(tree.type))
    end
  end
  NomsuCompiler.tree_to_inline_nomsu = function(self, tree, parenthesize_blocks, check, len)
    if parenthesize_blocks == nil then
      parenthesize_blocks = false
    end
    if check == nil then
      check = nil
    end
    if len == nil then
      len = 0
    end
    local recurse
    recurse = function(tree, nomsu, parenthesize_blocks)
      if nomsu == nil then
        nomsu = nil
      end
      if parenthesize_blocks == nil then
        parenthesize_blocks = false
      end
      return self:tree_to_inline_nomsu(tree, parenthesize_blocks, check, len + (nomsu and #tostring(nomsu) or 0))
    end
    local _exp_0 = tree.type
    if "FileChunks" == _exp_0 then
      return error("Cannot inline a FileChunks")
    elseif "Action" == _exp_0 then
      local nomsu = NomsuCode(tree.source)
      for i, bit in ipairs(tree) do
        if type(bit) == "string" then
          local clump_words = (type(tree[i - 1]) == 'string' and Parser.is_operator(bit) ~= Parser.is_operator(tree[i - 1]))
          if i > 1 and not clump_words then
            nomsu:append(" ")
          end
          nomsu:append(bit)
        else
          local arg_nomsu = recurse(bit, nomsu, parenthesize_blocks or (i == 1 or i < #tree))
          if not (tostring(arg_nomsu):match("^:") or i == 1) then
            nomsu:append(" ")
          end
          if bit.type == "Action" then
            arg_nomsu:parenthesize()
          end
          nomsu:append(arg_nomsu)
        end
        if check then
          check(len, nomsu, tree)
        end
      end
      return nomsu
    elseif "EscapedNomsu" == _exp_0 then
      local inner_nomsu = recurse(tree[1])
      if not (tree[1].type == "List" or tree[1].type == "Dict" or tree[1].type == "Var") then
        inner_nomsu:parenthesize()
      end
      local nomsu = NomsuCode(tree.source, "\\", inner_nomsu)
      if check then
        check(len, nomsu, tree)
      end
      return nomsu
    elseif "Block" == _exp_0 then
      local nomsu = NomsuCode(tree.source, ":")
      if check then
        check(len, nomsu, tree)
      end
      for i, line in ipairs(tree) do
        nomsu:append(i == 1 and " " or "; ")
        nomsu:append(recurse(line, nomsu, i == 1 or i < #tree))
        if check then
          check(len, nomsu, tree)
        end
      end
      if #tree > 1 or parenthesize_blocks then
        nomsu:parenthesize()
      end
      return nomsu
    elseif "Text" == _exp_0 then
      local add_text
      add_text = function(nomsu, tree)
        for i, bit in ipairs(tree) do
          if type(bit) == 'string' then
            local escaped = Parser.inline_escape(bit)
            nomsu:append(Parser.inline_escape(bit))
          elseif bit.type == "Text" then
            add_text(nomsu, bit)
          else
            local interp_nomsu = recurse(bit, nomsu)
            if bit.type ~= "Var" and bit.type ~= "List" and bit.type ~= "Dict" then
              interp_nomsu:parenthesize()
            elseif bit.type == "Var" and type(tree[i + 1]) == 'string' and not match(tree[i + 1], "^[ \n\t,.:;#(){}[%]]") then
              interp_nomsu:parenthesize()
            end
            nomsu:append("\\", interp_nomsu)
          end
          if check then
            check(len, nomsu, tree)
          end
        end
      end
      local nomsu = NomsuCode(tree.source)
      add_text(nomsu, tree)
      return NomsuCode(tree.source, '"', nomsu, '"')
    elseif "List" == _exp_0 or "Dict" == _exp_0 then
      local nomsu = NomsuCode(tree.source, (tree.type == "List" and "[" or "{"))
      for i, item in ipairs(tree) do
        if i > 1 then
          nomsu:append(", ")
        end
        nomsu:append(recurse(item, nomsu))
        if check then
          check(len, nomsu, tree)
        end
      end
      nomsu:append(tree.type == "List" and "]" or "}")
      return nomsu
    elseif "DictEntry" == _exp_0 then
      local key, value = tree[1], tree[2]
      local nomsu
      if key.type == "Text" and #key == 1 and Parser.is_identifier(key[1]) then
        nomsu = NomsuCode(key.source, key[1])
      else
        nomsu = recurse(key)
      end
      if key.type == "Action" or key.type == "Block" then
        nomsu:parenthesize()
      end
      assert(value.type ~= "Block", "Didn't expect to find a Block as a value in a dict")
      nomsu:append(":")
      if value then
        local value_nomsu = recurse(value, nomsu)
        if value.type == "Block" then
          value_nomsu:parenthesize()
        end
        nomsu:append(value_nomsu)
      end
      if check then
        check(len, nomsu, tree)
      end
      return nomsu
    elseif "IndexChain" == _exp_0 then
      local nomsu = NomsuCode(tree.source)
      for i, bit in ipairs(tree) do
        if i > 1 then
          nomsu:append(".")
        end
        local bit_nomsu
        if bit.type == "Text" and #bit == 1 and type(bit[1]) == 'string' and Parser.is_identifier(bit[1]) then
          bit_nomsu = bit[1]
        else
          bit_nomsu = recurse(bit, nomsu)
        end
        assert(bit.type ~= "Block")
        if bit.type == "Action" or bit.type == "IndexChain" or (bit.type == "Number" and i < #tree) then
          bit_nomsu:parenthesize()
        end
        nomsu:append(bit_nomsu)
        if check then
          check(len, nomsu, tree)
        end
      end
      return nomsu
    elseif "Number" == _exp_0 then
      return NomsuCode(tree.source, tostring(tree[1]))
    elseif "Var" == _exp_0 then
      return NomsuCode(tree.source, "%", tree[1])
    else
      return error("Unknown type: " .. tostring(tree.type))
    end
  end
  NomsuCompiler.tree_to_nomsu = function(self, tree, pop_comments)
    if pop_comments == nil then
      pop_comments = nil
    end
    if not (pop_comments) then
      local comment_set = { }
      local find_comments
      find_comments = function(t)
        if t.comments and t.source.filename == tree.source.filename then
          local _list_0 = t.comments
          for _index_0 = 1, #_list_0 do
            local c = _list_0[_index_0]
            comment_set[c] = true
          end
        end
        local _list_0 = t
        for _index_0 = 1, #_list_0 do
          local x = _list_0[_index_0]
          if AST.is_syntax_tree(x) then
            find_comments(x)
          end
        end
      end
      find_comments(tree)
      local comments
      do
        local _accum_0 = { }
        local _len_0 = 1
        for c in pairs(comment_set) do
          _accum_0[_len_0] = c
          _len_0 = _len_0 + 1
        end
        comments = _accum_0
      end
      table.sort(comments, function(a, b)
        return (a.pos > b.pos)
      end)
      pop_comments = function(pos, prefix, suffix)
        if prefix == nil then
          prefix = ''
        end
        if suffix == nil then
          suffix = ''
        end
        local nomsu = NomsuCode(tree.source)
        for i = #comments, 1, -1 do
          if comments[i].pos > pos then
            break
          end
          local comment
          comment, comments[i] = comments[i].comment, nil
          nomsu:append("#" .. (gsub(comment, "\n", "\n    ")) .. "\n")
          if comment:match("^\n.") then
            nomsu:append("\n")
          end
        end
        if #nomsu.bits == 0 then
          return ''
        end
        if not (prefix == '') then
          nomsu:prepend(prefix)
        end
        if not (suffix == '') then
          nomsu:append(suffix)
        end
        return nomsu
      end
    end
    local recurse
    recurse = function(t, pos)
      if pos == nil then
        pos = 0
      end
      if type(pos) ~= 'number' then
        pos = #tostring(pos):match("[ ]*([^\n]*)$")
      end
      local space = MAX_LINE - pos
      local inline
      for prefix, nomsu, tree in coroutine.wrap(function()
        inline = self:tree_to_inline_nomsu(t, false, coroutine.yield)
      end) do
        local len = #tostring(nomsu)
        if prefix + len > MAX_LINE then
          break
        end
        if tree.type == "Block" and (#tree > 1 or len > 20) then
          break
        end
        if tree.type == "Text" then
          local check_for_nl
          check_for_nl = function(tree)
            local found_nl = false
            for i, b in ipairs(tree) do
              if type(b) ~= 'string' and b.type == "Text" and check_for_nl(b) then
                return true
              end
              if i == 1 and type(b) == 'string' then
                b = b:match('^[\n]*(.*)')
              end
              found_nl = found_nl or (type(b) == 'string' and b:match('\n'))
              if found_nl and (type(b) ~= 'string' or b:match('[^\n]')) then
                return true
              end
            end
          end
          if check_for_nl(tree) then
            break
          end
        end
      end
      if inline and #tostring(inline) <= space then
        return inline
      end
      local indented = self:tree_to_nomsu(t, pop_comments, space)
      if t.type == "Action" and not (tree.type == "Block" or tree.type == "FileChunks") then
        indented = NomsuCode(t.source, "(..)\n    ", pop_comments(t.source.start), indented)
      end
      return indented
    end
    local _exp_0 = tree.type
    if "FileChunks" == _exp_0 then
      local setup = nil
      local nomsu = NomsuCode(tree.source, pop_comments(tree.source.start))
      for chunk_no, chunk in ipairs(tree) do
        if chunk_no > 1 then
          nomsu:append("\n\n" .. tostring(("~"):rep(80)) .. "\n\n")
        end
        nomsu:append(pop_comments(chunk.source.start))
        if chunk.type == "Block" then
          for line_no, line in ipairs(chunk) do
            if setup == nil then
              setup = line.type == "Action" and line.stub == "use %"
            elseif setup and not (line.type == "Action" and line.stub == "use %") then
              nomsu:append("\n", pop_comments(line.source.start))
              setup = false
            end
            nomsu:append(pop_comments(line.source.start, tostring(nomsu):match("\n\n$") and "" or "\n"))
            local line_nomsu = self:tree_to_nomsu(line, pop_comments)
            nomsu:append(line_nomsu)
            if line_no < #chunk then
              nomsu:append(line_nomsu:is_multiline() and "\n\n" or "\n")
            end
          end
          nomsu:append(pop_comments(chunk.source.stop, '\n'))
        else
          nomsu:append(recurse(chunk))
        end
        setup = false
      end
      nomsu:append(pop_comments(tree.source.stop, '\n'))
      if not (tostring(nomsu):match("\n$")) then
        nomsu:append('\n')
      end
      return nomsu
    elseif "Action" == _exp_0 then
      local pos, next_space = tree.source.start, ''
      local nomsu = NomsuCode(tree.source, pop_comments(pos))
      for i, bit in ipairs(tree) do
        if next_space == "\n.." or (next_space == " " and nomsu:trailing_line_len() > MAX_LINE) then
          nomsu:append("\n", pop_comments(pos), '..')
          next_space = ""
        end
        if type(bit) == "string" then
          if not (type(tree[i - 1]) == 'string' and Parser.is_operator(tree[i - 1]) ~= Parser.is_operator(bit)) then
            nomsu:append(next_space)
          end
          nomsu:append(bit)
          next_space = ' '
        elseif bit.type == "Block" then
          nomsu:append(recurse(bit, #tostring(nomsu):match('[^\n]*$')))
          pos = bit.source.stop
          next_space = inline and " " or "\n.."
        else
          nomsu:append(next_space)
          local bit_nomsu = recurse(bit, #tostring(nomsu):match('[^\n]*$'))
          if bit.type == "Action" and not bit_nomsu:is_multiline() then
            bit_nomsu:parenthesize()
          end
          nomsu:append(bit_nomsu)
          pos = bit.source.stop
          next_space = bit_nomsu:is_multiline() and "\n.." or " "
        end
      end
      nomsu:append(pop_comments(tree.source.stop, '\n'))
      return nomsu
    elseif "EscapedNomsu" == _exp_0 then
      return NomsuCode(tree.source, "\\", recurse(tree[1], 1))
    elseif "Block" == _exp_0 then
      local nomsu = NomsuCode(tree.source, pop_comments(tree.source.start))
      for i, line in ipairs(tree) do
        nomsu:append(pop_comments(line.source.start, i > 1 and '\n' or ''))
        local line_nomsu = recurse(line)
        nomsu:append(line_nomsu)
        if i < #tree then
          nomsu:append(tostring(line_nomsu):match('\n[^\n]*\n') and "\n\n" or "\n")
        end
      end
      nomsu:append(pop_comments(tree.source.stop, '\n'))
      return NomsuCode(tree.source, ":\n    ", nomsu)
    elseif "Text" == _exp_0 then
      local max_line = math.floor(1.5 * MAX_LINE)
      local add_text
      add_text = function(nomsu, tree)
        for i, bit in ipairs(tree) do
          if type(bit) == 'string' then
            bit = Parser.escape(bit)
            local bit_lines = Files.get_lines(bit)
            for j, line in ipairs(bit_lines) do
              if j > 1 then
                nomsu:append("\n")
              elseif #line > 10 and nomsu:trailing_line_len() > max_line then
                nomsu:append("\\\n..")
              end
              while #line > 0 do
                local space = max_line - nomsu:trailing_line_len()
                local split = find(line, "[%p%s]", space)
                if not split or split > space + 10 then
                  split = space + 10
                end
                if #line - split < 10 then
                  split = #line
                end
                local bite
                bite, line = sub(line, 1, split), sub(line, split + 1, -1)
                nomsu:append(bite)
                if #line > 0 then
                  nomsu:append("\\\n..")
                end
              end
            end
          elseif bit.type == "Text" then
            add_text(nomsu, bit)
          else
            nomsu:append("\\")
            local interp_nomsu = recurse(bit, #tostring(nomsu):match('[^\n]*$'))
            if not (interp_nomsu:is_multiline()) then
              if bit.type == "Var" then
                if type(tree[i + 1]) == 'string' and not match(tree[i + 1], "^[ \n\t,.:;#(){}[%]]") then
                  interp_nomsu:parenthesize()
                end
              elseif bit.type ~= "List" and bit.type ~= "Dict" then
                interp_nomsu:parenthesize()
              end
            end
            nomsu:append(interp_nomsu)
            if interp_nomsu:is_multiline() and i < #tree then
              nomsu:append("\n..")
            end
          end
        end
      end
      local nomsu = NomsuCode(tree.source)
      add_text(nomsu, tree)
      if nomsu:is_multiline() and tostring(nomsu):match("\n$") then
        nomsu:append('\\("")')
      end
      return NomsuCode(tree.source, '".."\n    ', nomsu)
    elseif "List" == _exp_0 or "Dict" == _exp_0 then
      assert(#tree > 0)
      local nomsu = NomsuCode(tree.source, pop_comments(tree[1].source.start))
      for i, item in ipairs(tree) do
        if nomsu:trailing_line_len() == 0 then
          nomsu:append(pop_comments(item.source.start))
        end
        local inline_nomsu = self:tree_to_inline_nomsu(item)
        local item_nomsu = #tostring(inline_nomsu) <= MAX_LINE and inline_nomsu or recurse(item, #tostring(nomsu):match('[^\n]*$'))
        nomsu:append(item_nomsu)
        if i < #tree then
          nomsu:append((item_nomsu:is_multiline() or nomsu:trailing_line_len() + #tostring(item_nomsu) >= MAX_LINE) and '\n' or ', ')
        end
      end
      nomsu:append(pop_comments(tree.source.stop, '\n'))
      if tree.type == "List" then
        return NomsuCode(tree.source, "[..]\n    ", nomsu)
      else
        return NomsuCode(tree.source, "{..}\n    ", nomsu)
      end
    elseif "DictEntry" == _exp_0 then
      local key, value = tree[1], tree[2]
      local nomsu
      if key.type == "Text" and #key == 1 and Parser.is_identifier(key[1]) then
        nomsu = NomsuCode(key.source, key[1])
      else
        nomsu = self:tree_to_inline_nomsu(key)
      end
      if key.type == "Action" or key.type == "Block" then
        nomsu:parenthesize()
      end
      nomsu:append(": ", recurse(value, #tostring(nomsu)))
      return nomsu
    elseif "IndexChain" == _exp_0 or "Number" == _exp_0 or "Var" == _exp_0 then
      return self:tree_to_inline_nomsu(tree)
    else
      return error("Unknown type: " .. tostring(tree.type))
    end
  end
end
return NomsuCompiler