code / nomsu

   1 local NomsuCode
   2 NomsuCode = require("code_obj").NomsuCode
   3 local find, sub, match
   4 do
   5   local _obj_0 = string
   6   find, sub, match = _obj_0.find, _obj_0.sub, _obj_0.match
   7 end
   8 local R, P, S
   9 do
  10   local _obj_0 = require('lpeg')
  11   R, P, S = _obj_0.R, _obj_0.P, _obj_0.S
  12 end
  13 local re = require('re')
  14 local pretty_error = require("pretty_errors")
  15 local MAX_LINE = 80
  16 local GOLDEN_RATIO = ((math.sqrt(5) - 1) / 2)
  17 local utf8_char_patt = (R("\194\223") * R("\128\191") + R("\224\239") * R("\128\191") * R("\128\191") + R("\240\244") * R("\128\191") * R("\128\191") * R("\128\191"))
  18 local operator_char = S("#'`~@^&*+=<>?/%!|\\-") + (P("\xE2") * (R("\x88\x8B") + R("\xA8\xAB")) * R("\128\191"))
  19 local operator_patt = operator_char ^ 1 * -1
  20 local identifier_patt = (R("az", "AZ", "09") + P("_") + (-operator_char * utf8_char_patt)) ^ 1 * -1
  21 local is_operator
  22 is_operator = function(s)
  23   return type(s) == 'string' and not not operator_patt:match(s)
  24 end
  25 local is_identifier
  26 is_identifier = function(s)
  27   return type(s) == 'string' and not not identifier_patt:match(s)
  28 end
  29 local can_be_unary
  30 can_be_unary = function(t)
  31   return t.type == "Action" and #t == 2 and is_operator(t[1]) and type(t[2]) ~= 'string' and t[2].type ~= "Block" and not (t[2].type == "Number" and t[1] == "-")
  32 end
  33 local inline_escaper = re.compile("{~ (%utf8_char / ('\"' -> '\\\"') / ('\n' -> '\\n') / ('\t' -> '\\t') / ('\b' -> '\\b') / ('\a' -> '\\a') / ('\v' -> '\\v') / ('\f' -> '\\f') / ('\r' -> '\\r') / ('\\' -> '\\\\') / ([^ -~] -> escape) / .)* ~}", {
  34   utf8_char = utf8_char_patt,
  35   escape = (function(self)
  36     return ("\\%03d"):format(self:byte())
  37   end)
  38 })
  39 local inline_escape
  40 inline_escape = function(s)
  41   return inline_escaper:match(s)
  42 end
  43 local escaper = re.compile("{~ (%utf8_char / ('\\' -> '\\\\') / [\n\r\t -~] / (. -> escape))* ~}", {
  44   utf8_char = utf8_char_patt,
  45   escape = (function(self)
  46     return ("\\%03d"):format(self:byte())
  47   end)
  48 })
  49 local escape
  50 escape = function(s)
  51   return escaper:match(s)
  52 end
  53 local tree_to_inline_nomsu
  54 tree_to_inline_nomsu = function(tree)
  55   local _exp_0 = tree.type
  56   if "Action" == _exp_0 then
  57     local nomsu = NomsuCode:from(tree.source)
  58     if can_be_unary(tree) then
  59       nomsu:add(tree[1])
  60       local arg_nomsu = tree_to_inline_nomsu(tree[2])
  61       if tree[2].type == "MethodCall" or tree[2].type == "Action" then
  62         arg_nomsu:parenthesize()
  63       end
  64       nomsu:add(arg_nomsu)
  65       return nomsu
  66     end
  67     local num_args, num_words = 0, 0
  68     for i, bit in ipairs(tree) do
  69       if type(bit) == "string" then
  70         num_words = num_words + 1
  71         local clump_words
  72         if type(tree[i - 1]) == 'string' then
  73           clump_words = is_operator(bit) ~= is_operator(tree[i - 1])
  74         else
  75           clump_words = bit == "'"
  76         end
  77         if i > 1 and not clump_words then
  78           nomsu:add(" ")
  79         end
  80         nomsu:add(bit)
  81       else
  82         num_args = num_args + 1
  83         local arg_nomsu = tree_to_inline_nomsu(bit)
  84         if tree[i + 1] == "'" and bit.type == "Action" and can_be_unary(bit) then
  85           arg_nomsu:parenthesize()
  86         end
  87         if bit.type == "Block" then
  88           if i ~= #tree then
  89             if i > 1 then
  90               nomsu:add(" ")
  91             end
  92             arg_nomsu:parenthesize()
  93           end
  94         else
  95           if i > 1 then
  96             nomsu:add(" ")
  97           end
  98           if bit.type == "MethodCall" then
  99             arg_nomsu:parenthesize()
 100           elseif bit.type == "Action" and not can_be_unary(bit) then
 101             arg_nomsu:parenthesize()
 102           end
 103         end
 104         nomsu:add(arg_nomsu)
 105       end
 106     end
 107     if num_args == 1 and num_words == 0 then
 108       nomsu:add("()")
 109     end
 110     return nomsu
 111   elseif "MethodCall" == _exp_0 then
 112     local target_nomsu = tree_to_inline_nomsu(tree[1])
 113     if tree[1].type == "Block" then
 114       target_nomsu:parenthesize()
 115     end
 116     local nomsu = NomsuCode:from(tree.source, target_nomsu, ", ")
 117     if #tree > 2 then
 118       nomsu:add("(")
 119     end
 120     for i = 2, #tree do
 121       if i > 2 then
 122         nomsu:add("; ")
 123       end
 124       nomsu:add(tree_to_inline_nomsu(tree[i]))
 125     end
 126     if #tree > 2 then
 127       nomsu:add(")")
 128     end
 129     return nomsu
 130   elseif "EscapedNomsu" == _exp_0 then
 131     local inner_nomsu = tree_to_inline_nomsu(tree[1])
 132     if not (tree[1].type == "List" or tree[1].type == "Dict" or tree[1].type == "Var") then
 133       inner_nomsu:parenthesize()
 134     end
 135     return NomsuCode:from(tree.source, "\\", inner_nomsu)
 136   elseif "Block" == _exp_0 then
 137     local nomsu = NomsuCode:from(tree.source, ":")
 138     for i, line in ipairs(tree) do
 139       nomsu:add(i == 1 and " " or "; ")
 140       nomsu:add(tree_to_inline_nomsu(line))
 141     end
 142     if #tree > 1 then
 143       nomsu:parenthesize()
 144     end
 145     return nomsu
 146   elseif "Text" == _exp_0 then
 147     local add_text
 148     add_text = function(nomsu, tree)
 149       for i, bit in ipairs(tree) do
 150         if type(bit) == 'string' then
 151           local escaped = inline_escape(bit)
 152           nomsu:add(inline_escape(bit))
 153         elseif bit.type == "Text" then
 154           add_text(nomsu, bit)
 155         else
 156           local interp_nomsu = tree_to_inline_nomsu(bit)
 157           if bit.type ~= "Var" and bit.type ~= "List" and bit.type ~= "Dict" then
 158             interp_nomsu:parenthesize()
 159           elseif bit.type == "Var" and type(bit[1]) == 'string' and type(tree[i + 1]) == 'string' and not match(tree[i + 1], "^[ \n\t,.:;#(){}[%]]") then
 160             interp_nomsu:parenthesize()
 161           end
 162           nomsu:add("\\", interp_nomsu)
 163         end
 164       end
 165     end
 166     local nomsu = NomsuCode:from(tree.source)
 167     add_text(nomsu, tree)
 168     return NomsuCode:from(tree.source, '"', nomsu, '"')
 169   elseif "List" == _exp_0 or "Dict" == _exp_0 then
 170     local nomsu = NomsuCode:from(tree.source, (tree.type == "List" and "[" or "{"))
 171     for i, item in ipairs(tree) do
 172       if i > 1 then
 173         nomsu:add(", ")
 174       end
 175       local item_nomsu = tree_to_inline_nomsu(item, true)
 176       if item.type == "MethodCall" or (item.type == "Block" and i < #tree) then
 177         item_nomsu:parenthesize()
 178       end
 179       nomsu:add(item_nomsu)
 180     end
 181     nomsu:add(tree.type == "List" and "]" or "}")
 182     return nomsu
 183   elseif "DictEntry" == _exp_0 then
 184     local key, value = tree[1], tree[2]
 185     local nomsu = NomsuCode:from(tree.source)
 186     if key.type ~= "Index" then
 187       key = {
 188         type = "Index",
 189         source = key.source,
 190         key
 191       }
 192     end
 193     nomsu:add(tree_to_inline_nomsu(key))
 194     if value then
 195       nomsu:add(" = ")
 196       local value_nomsu = tree_to_inline_nomsu(value)
 197       if value.type == "Block" or value.type == "Action" or value.type == "MethodCall" then
 198         value_nomsu:parenthesize()
 199       end
 200       nomsu:add(value_nomsu)
 201     end
 202     return nomsu
 203   elseif "Index" == _exp_0 then
 204     local key = tree[1]
 205     local nomsu = NomsuCode:from(key.source, ".")
 206     local key_nomsu
 207     if key.type == "Text" and #key == 1 and is_identifier(key[1]) then
 208       key_nomsu = key[1]
 209     else
 210       key_nomsu = tree_to_inline_nomsu(key)
 211     end
 212     local _exp_1 = key.type
 213     if "Block" == _exp_1 or "Action" == _exp_1 or "MethodCall" == _exp_1 or "IndexChain" == _exp_1 then
 214       key_nomsu:parenthesize()
 215     end
 216     return NomsuCode:from(key.source, ".", key_nomsu)
 217   elseif "IndexChain" == _exp_0 then
 218     local nomsu = NomsuCode:from(tree.source)
 219     local target = tree[1]
 220     local target_nomsu = tree_to_inline_nomsu(target)
 221     local _exp_1 = target.type
 222     if "Action" == _exp_1 or "MethodCall" == _exp_1 or "EscapedNomsu" == _exp_1 then
 223       target_nomsu:parenthesize()
 224     elseif "Number" == _exp_1 then
 225       if target_nomsu:text():match("%.") then
 226         target_nomsu:parenthesize()
 227       end
 228     end
 229     nomsu:add(target_nomsu)
 230     for i = 2, #tree do
 231       if tree[i].type ~= "Index" then
 232         tree[i] = {
 233           type = "Index",
 234           source = tree[i].source,
 235           tree[i]
 236         }
 237       end
 238       nomsu:add(tree_to_inline_nomsu(tree[i]))
 239     end
 240     return nomsu
 241   elseif "Number" == _exp_0 then
 242     local n = tostring(tree[1])
 243     local s
 244     if n:match("^-*0x") then
 245       s = n:upper():gsub("0X", "0x")
 246     elseif tree.hex and tonumber((n:gsub("_", ""))) < 0 then
 247       s = ("-0x%X"):format(-tree[1])
 248     elseif tree.hex then
 249       s = ("0x%X"):format(tree[1])
 250     else
 251       s = n
 252     end
 253     return NomsuCode:from(tree.source, s)
 254   elseif "Var" == _exp_0 then
 255     local varname = tree[1]
 256     if type(varname) == "string" then
 257       return NomsuCode:from(tree.source, "$", varname)
 258     else
 259       return NomsuCode:from(tree.source, "$(", tree_to_inline_nomsu(varname), ")")
 260     end
 261   elseif "FileChunks" == _exp_0 then
 262     return error("Can't inline a FileChunks")
 263   elseif "Comment" == _exp_0 then
 264     return NomsuCode:from(tree.source)
 265   elseif "Error" == _exp_0 then
 266     local err_msg = pretty_error({
 267       title = "Parse error",
 268       error = tree.error,
 269       hint = tree.hint,
 270       source = tree:get_source_file(),
 271       start = tree.source.start,
 272       stop = tree.source.stop,
 273       filename = tree.source.filename
 274     })
 275     return error(err_msg)
 276   else
 277     return error("Unknown type: " .. tostring(tree.type))
 278   end
 279 end
 280 local tree_to_nomsu
 281 tree_to_nomsu = function(tree)
 282   local nomsu = NomsuCode:from(tree.source)
 283   local recurse
 284   recurse = function(t, argnum)
 285     if argnum == nil then
 286       argnum = nil
 287     end
 288     local space = MAX_LINE - nomsu:trailing_line_len()
 289     local try_inline = true
 290     for subtree in coroutine.wrap(function()
 291       return (t:with(coroutine.yield) and nil)
 292     end) do
 293       local _exp_0 = subtree.type
 294       if "Comment" == _exp_0 then
 295         try_inline = false
 296       elseif "Block" == _exp_0 then
 297         if #subtree > 1 then
 298           try_inline = false
 299         end
 300       elseif "Text" == _exp_0 then
 301         local indented = tree_to_nomsu(subtree)
 302         local indented_lines
 303         do
 304           local _accum_0 = { }
 305           local _len_0 = 1
 306           local _list_0 = indented:text():lines()
 307           for _index_0 = 1, #_list_0 do
 308             local line = _list_0[_index_0]
 309             if line:match("^    +([^ ].*)") then
 310               _accum_0[_len_0] = line
 311               _len_0 = _len_0 + 1
 312             end
 313           end
 314           indented_lines = _accum_0
 315         end
 316         for i = #indented_lines, 1, -1 do
 317           if indented_lines[i]:match("^ *\\;$") then
 318             table.remove(indented_lines, i)
 319           end
 320         end
 321         if #indented_lines > 1 or (#indented_lines == 1 and #indented_lines[1] > MAX_LINE + 8) then
 322           try_inline = false
 323         end
 324       end
 325     end
 326     local inline_nomsu
 327     if try_inline then
 328       inline_nomsu = tree_to_inline_nomsu(t)
 329       if t.type == "MethodCall" then
 330         inline_nomsu:parenthesize()
 331       elseif t.type == "Action" and not can_be_unary(t) then
 332         inline_nomsu:parenthesize()
 333       end
 334       if #inline_nomsu:text() <= space or #inline_nomsu:text() <= 8 then
 335         if t.type ~= "Text" then
 336           return inline_nomsu
 337         end
 338       end
 339     end
 340     local indented = tree_to_nomsu(t)
 341     if t.type == "Action" or t.type == "MethodCall" then
 342       if indented:is_multiline() then
 343         if argnum == nil or argnum == 1 then
 344           return NomsuCode:from(t.source, "(\n    ", indented, "\n)")
 345         else
 346           return NomsuCode:from(t.source, "\n    ", indented)
 347         end
 348       elseif argnum and argnum > 1 then
 349         return NomsuCode:from(t.source, "\n    ", indented)
 350       else
 351         indented:parenthesize()
 352       end
 353     end
 354     local indented_lines
 355     do
 356       local _accum_0 = { }
 357       local _len_0 = 1
 358       local _list_0 = indented:text():lines()
 359       for _index_0 = 1, #_list_0 do
 360         local line = _list_0[_index_0]
 361         if line:match("^    +([^ ].*)") then
 362           _accum_0[_len_0] = line
 363           _len_0 = _len_0 + 1
 364         end
 365       end
 366       indented_lines = _accum_0
 367     end
 368     if t.type == "Text" then
 369       for i = #indented_lines, 1, -1 do
 370         if indented_lines[i]:match("^ *\\;$") then
 371           table.remove(indented_lines, i)
 372         end
 373       end
 374     end
 375     if inline_nomsu and (#inline_nomsu:text() < MAX_LINE or #inline_nomsu:text() <= space) and #indented_lines <= 1 then
 376       return inline_nomsu
 377     end
 378     return indented
 379   end
 380   local _exp_0 = tree.type
 381   if "FileChunks" == _exp_0 then
 382     if tree.shebang then
 383       nomsu:add(tree.shebang, "\n")
 384     end
 385     for chunk_no, chunk in ipairs(tree) do
 386       if chunk_no > 1 then
 387         nomsu:add("\n\n" .. tostring(("~"):rep(80)) .. "\n\n")
 388       end
 389       if chunk.type == "Block" then
 390         nomsu:add(NomsuCode:from(chunk.source, table.unpack(tree_to_nomsu(chunk).bits, 2)))
 391       else
 392         nomsu:add(tree_to_nomsu(chunk))
 393       end
 394     end
 395     return nomsu
 396   elseif "Action" == _exp_0 then
 397     if can_be_unary(tree) and not can_be_unary(tree[2]) then
 398       nomsu:add(tree[1])
 399       nomsu:add(recurse(tree[2]))
 400       return nomsu
 401     end
 402     local next_space = ""
 403     local word_buffer = { }
 404     local num_args, num_words = 0, 0
 405     for i, bit in ipairs(tree) do
 406       local _continue_0 = false
 407       repeat
 408         if type(bit) == "string" then
 409           num_words = num_words + 1
 410           if #word_buffer > 0 and is_operator(bit) == is_operator(word_buffer[#word_buffer]) then
 411             table.insert(word_buffer, " ")
 412           end
 413           table.insert(word_buffer, bit)
 414           _continue_0 = true
 415           break
 416         end
 417         if #word_buffer > 0 then
 418           local words = table.concat(word_buffer)
 419           if next_space == " " then
 420             if nomsu:trailing_line_len() + #words > MAX_LINE and nomsu:trailing_line_len() > 8 then
 421               next_space = "\n.."
 422             elseif word_buffer[1] == "'" then
 423               next_space = ""
 424             end
 425           end
 426           nomsu:add(next_space, words)
 427           word_buffer = { }
 428           next_space = " "
 429         end
 430         num_args = num_args + 1
 431         local bit_nomsu = recurse(bit, i)
 432         if tree[i + 1] == "'" and bit.type == "Action" and not bit_nomsu:is_multiline() and can_be_unary(bit) then
 433           bit_nomsu:parenthesize()
 434         end
 435         if bit.type == "Block" then
 436           if not bit_nomsu:is_multiline() and (#bit_nomsu:text() > nomsu:trailing_line_len() * GOLDEN_RATIO and #bit_nomsu:text() > 8) or #bit_nomsu:text() + nomsu:trailing_line_len() > MAX_LINE then
 437             bit_nomsu = tree_to_nomsu(bit)
 438           end
 439         elseif (not bit_nomsu:is_multiline() and nomsu:trailing_line_len() + #bit_nomsu:text() > MAX_LINE and nomsu:trailing_line_len() > 8) then
 440           if next_space == " " and #bit_nomsu:text() < MAX_LINE then
 441             if i == #tree then
 442               bit_nomsu = tree_to_inline_nomsu(bit)
 443               next_space = "\n    "
 444             elseif bit.type == "List" or bit.type == "Dict" then
 445               bit_nomsu = tree_to_nomsu(bit)
 446             else
 447               next_space = "\n.."
 448             end
 449           elseif bit.type == 'Action' or bit.type == "MethodCall" then
 450             bit_nomsu = NomsuCode:from(bit.source, "\n    ", tree_to_nomsu(bit))
 451           else
 452             bit_nomsu = tree_to_nomsu(bit)
 453           end
 454         end
 455         if not (next_space == " " and bit_nomsu:text():match("^[:\n]")) then
 456           nomsu:add(next_space)
 457         end
 458         nomsu:add(bit_nomsu)
 459         next_space = (bit.type == "Block" or bit_nomsu:text():matches("\n    [^\n]*$")) and "\n.." or " "
 460         _continue_0 = true
 461       until true
 462       if not _continue_0 then
 463         break
 464       end
 465     end
 466     if #word_buffer > 0 then
 467       local words = table.concat(word_buffer)
 468       if next_space == " " then
 469         if nomsu:trailing_line_len() + #words > MAX_LINE + 8 and nomsu:trailing_line_len() > 8 then
 470           next_space = "\n.."
 471         elseif word_buffer[1] == "'" then
 472           next_space = ""
 473         end
 474       end
 475       nomsu:add(next_space, words)
 476       next_space = " "
 477     end
 478     if num_args == 1 and num_words == 0 then
 479       if next_space ~= " " then
 480         nomsu:add(next_space)
 481       end
 482       nomsu:add("()")
 483     end
 484     return nomsu
 485   elseif "MethodCall" == _exp_0 then
 486     local target_nomsu = recurse(tree[1])
 487     if tree[1].type == "Block" and not target_nomsu:is_multiline() then
 488       target_nomsu:parenthesize()
 489     end
 490     nomsu:add(target_nomsu, ", ")
 491     local inner_nomsu = NomsuCode()
 492     for i = 2, #tree do
 493       if i > 2 then
 494         inner_nomsu:add("\n")
 495       end
 496       inner_nomsu:add(tree_to_nomsu(tree[i]))
 497     end
 498     if #tree == 2 and nomsu:trailing_line_len() + #inner_nomsu:text():match("^[^\n]*") < MAX_LINE then
 499       nomsu:add(inner_nomsu)
 500     else
 501       nomsu:add("\n    ", inner_nomsu)
 502     end
 503     return nomsu
 504   elseif "EscapedNomsu" == _exp_0 then
 505     nomsu = recurse(tree[1])
 506     if tree[1].type == 'Block' and not nomsu:is_multiline() then
 507       nomsu:parenthesize()
 508     end
 509     return NomsuCode:from(tree.source, "\\", nomsu)
 510   elseif "Block" == _exp_0 then
 511     local prev_line, needs_space = nil, { }
 512     for i, line in ipairs(tree) do
 513       local line_nomsu = tree_to_nomsu(line)
 514       if i > 1 then
 515         nomsu:add("\n")
 516         if tree[i - 1].type ~= "Comment" then
 517           needs_space[i] = (line_nomsu:is_multiline() and prev_line:is_multiline())
 518           if (tree[i].type == "Comment" or needs_space[i] or needs_space[i - 1] or prev_line:text():match("\n        [^\n]*$")) then
 519             nomsu:add("\n")
 520           end
 521         end
 522       end
 523       nomsu:add(line_nomsu)
 524       prev_line = line_nomsu
 525     end
 526     return NomsuCode:from(tree.source, ":\n    ", nomsu)
 527   elseif "Text" == _exp_0 then
 528     local max_line = MAX_LINE + 8
 529     local add_text
 530     add_text = function(tree)
 531       for i, bit in ipairs(tree) do
 532         if type(bit) == 'string' then
 533           bit = escape(bit)
 534           for j, line in ipairs(bit:lines()) do
 535             if j > 1 then
 536               if nomsu:text():match(" $") then
 537                 nomsu:add("\\;")
 538               end
 539               nomsu:add("\n")
 540             elseif #line > 10 and nomsu:trailing_line_len() > max_line then
 541               nomsu:add("\\\n..")
 542             end
 543             while #line > 0 do
 544               local space = max_line - nomsu:trailing_line_len()
 545               local split = find(line, "[%p%s]", space)
 546               if not split or split > space + 16 then
 547                 split = space + 16
 548               end
 549               if #line - split < 16 then
 550                 split = #line
 551               end
 552               local bite
 553               bite, line = sub(line, 1, split), sub(line, split + 1, -1)
 554               nomsu:add(bite)
 555               if #line > 0 then
 556                 nomsu:add("\\\n..")
 557               end
 558             end
 559           end
 560         elseif bit.type == "Text" then
 561           add_text(bit)
 562         else
 563           nomsu:add("\\")
 564           local interp_nomsu = recurse(bit)
 565           if interp_nomsu:is_multiline() then
 566             local curr_indent = nomsu:text():match("\n( *)[^\n]*$") or nomsu:text():match("^( *)")
 567             interp_nomsu = NomsuCode((interp_nomsu:text():gsub("\n", "\n" .. curr_indent)))
 568           else
 569             local space = max_line - nomsu:trailing_line_len()
 570             if bit.type == "Var" then
 571               local next_str = tree[i + 1]
 572               while type(next_str) == 'table' and next_str.type == 'Text' do
 573                 next_str = next_str[1]
 574               end
 575               if type(next_str) == 'string' and not match(next_str, "^[ \n\t,.:;#(){}[%]]") then
 576                 interp_nomsu:parenthesize()
 577               end
 578             elseif #interp_nomsu:text() > space then
 579               local interp_nomsu2
 580               if bit.type == "Action" or bit.type == "MethodCall" then
 581                 interp_nomsu2 = NomsuCode:from(bit.source, "(\n    ", tree_to_nomsu(bit), "\n)")
 582               else
 583                 interp_nomsu2 = tree_to_nomsu(bit)
 584               end
 585               if #interp_nomsu2:text():lines() > 3 or #interp_nomsu2:text() >= MAX_LINE * GOLDEN_RATIO then
 586                 local curr_indent = nomsu:text():match("\n( *)[^\n]*$") or nomsu:text():match("^( *)")
 587                 interp_nomsu2 = NomsuCode((interp_nomsu2:text():gsub("\n", "\n" .. curr_indent)))
 588                 interp_nomsu = interp_nomsu2
 589               else
 590                 nomsu:add("\n..\\")
 591                 if bit.type == "EscapedNomsu" or bit.type == "Block" or bit.type == "IndexChain" then
 592                   interp_nomsu:parenthesize()
 593                 end
 594               end
 595             elseif bit.type == "EscapedNomsu" or bit.type == "Block" or bit.type == "IndexChain" then
 596               interp_nomsu:parenthesize()
 597             elseif bit.type == "Action" and can_be_unary(bit) then
 598               interp_nomsu:parenthesize()
 599             end
 600           end
 601           nomsu:add(interp_nomsu)
 602           if interp_nomsu:is_multiline() and bit.type == "Block" then
 603             nomsu:add("\n..")
 604           end
 605         end
 606       end
 607     end
 608     add_text(tree)
 609     if nomsu:text():match(" $") then
 610       nomsu:add("\\;")
 611     end
 612     return NomsuCode:from(tree.source, '("\n    ', nomsu, '\n")')
 613   elseif "List" == _exp_0 or "Dict" == _exp_0 then
 614     if #tree == 0 then
 615       nomsu:add(tree.type == "List" and "[]" or "{}")
 616       return nomsu
 617     end
 618     if #tree == 1 and tree[1].type == "Block" then
 619       local block_lua = recurse(tree[1])
 620       if block_lua:is_multiline() then
 621         block_lua:add("\n")
 622       end
 623       if tree.type == "List" then
 624         return NomsuCode:from(tree.source, "[", block_lua, "]")
 625       else
 626         return NomsuCode:from(tree.source, "{", block_lua, "}")
 627       end
 628     end
 629     local sep = ''
 630     local prev_item, needs_space = nil, { }
 631     for i, item in ipairs(tree) do
 632       local item_nomsu
 633       if item.type == 'MethodCall' then
 634         item_nomsu = recurse(item)
 635       elseif item.type == 'Comment' then
 636         item_nomsu = tree_to_nomsu(item)
 637         if i > 1 then
 638           sep = '\n'
 639         end
 640       elseif item.type == 'Block' and #item == 1 then
 641         item_nomsu = tree_to_nomsu(item[1])
 642         item_nomsu:prepend(": ")
 643         if i > 1 then
 644           sep = '\n'
 645         end
 646       else
 647         item_nomsu = tree_to_inline_nomsu(item)
 648         if nomsu:trailing_line_len() + #item_nomsu:text() > MAX_LINE then
 649           if i > 1 then
 650             sep = '\n'
 651           end
 652           item_nomsu = item.type == "Action" and tree_to_nomsu(item) or recurse(item)
 653         end
 654       end
 655       nomsu:add(sep)
 656       if sep == '\n' then
 657         if i > 1 and tree[i - 1].type ~= "Comment" then
 658           needs_space[i] = (item_nomsu:is_multiline() and prev_item:is_multiline())
 659           if (tree[i].type == "Comment" or needs_space[i] or needs_space[i - 1] or prev_item:text():match("\n        [^\n]*$")) then
 660             nomsu:add("\n")
 661           end
 662         end
 663       end
 664       nomsu:add(item_nomsu)
 665       prev_item = item_nomsu
 666       if item_nomsu:is_multiline() or item.type == 'Comment' or item.type == "Block" or nomsu:trailing_line_len() + #tostring(item_nomsu) >= MAX_LINE then
 667         sep = '\n'
 668       else
 669         sep = ', '
 670       end
 671     end
 672     if tree.type == "List" then
 673       return NomsuCode:from(tree.source, "[\n    ", nomsu, "\n]")
 674     else
 675       return NomsuCode:from(tree.source, "{\n    ", nomsu, "\n}")
 676     end
 677   elseif "DictEntry" == _exp_0 then
 678     local key, value = tree[1], tree[2]
 679     nomsu = NomsuCode:from(tree.source)
 680     if key.type ~= "Index" then
 681       key = {
 682         type = "Index",
 683         source = key.source,
 684         key
 685       }
 686     end
 687     nomsu:add(tree_to_nomsu(key))
 688     if value then
 689       local value_nomsu = recurse(value)
 690       nomsu:add(" = ", value_nomsu)
 691     end
 692     return nomsu
 693   elseif "Comment" == _exp_0 then
 694     nomsu:add("###", (tree[1]:gsub("\n", "\n    ")))
 695     return nomsu
 696   elseif "IndexChain" == _exp_0 or "Index" == _exp_0 or "Number" == _exp_0 or "Var" == _exp_0 or "Comment" == _exp_0 or "Error" == _exp_0 then
 697     return tree_to_inline_nomsu(tree)
 698   else
 699     return error("Unknown type: " .. tostring(tree.type))
 700   end
 701 end
 702 return {
 703   tree_to_nomsu = tree_to_nomsu,
 704   tree_to_inline_nomsu = tree_to_inline_nomsu
 705 }