code / nomsu

   1 -- 
   2 -- This file contains the source code of the Nomsu compiler.
   3 --
   4 unpack or= table.unpack
   5 {:match, :sub, :gsub, :format, :byte, :find} = string
   6 {:LuaCode, :Source} = require "code_obj"
   7 require "text"
   8 SyntaxTree = require "syntax_tree"
   9 Files = require "files"
  10 
  11 pretty_error = require("pretty_errors")
  12 fail_at = (source, msg)->
  13     local file
  14     if SyntaxTree\is_instance(source)
  15         file = source\get_source_file!
  16         source = source.source
  17     elseif type(source) == 'string'
  18         source = Source\from_string(source)
  19     elseif not Source\is_instance(source)
  20         -- debug.getinfo() output:
  21         assert(source.short_src and source.currentline)
  22         file = Files.read(source.short_src)
  23         assert file, "Could not find #{source.short_src}"
  24         lines = file\lines!
  25         start = 1
  26         for i=1,source.currentline-1
  27             start += #lines[i]
  28         stop = start + #lines[source.currentline]
  29         source = Source(source.short_src, start, stop)
  30 
  31     if source and not file
  32         file = Files.read(source.filename)
  33     if not file
  34         if NOMSU_PREFIX
  35             path = "#{NOMSU_PREFIX}/share/nomsu/#{table.concat NOMSU_VERSION, "."}/#{source.filename}"
  36             file = Files.read(path)
  37     if not file
  38         error("Can't find file: "..tostring(source.filename))
  39 
  40     title, err_msg, hint = msg\match("([^:]*):[ \n]+(.*)[ \n]+Hint: (.*)")
  41     if not err_msg
  42         err_msg, hint = msg\match("(.*)[ \n]+Hint:[ \n]+(.*)")
  43         title = "Failure"
  44     if not err_msg
  45         title, err_msg = msg\match("([^:]*):[ \n]+(.*)")
  46     if not err_msg
  47         err_msg = msg
  48         title = "Failure"
  49 
  50     err_str = pretty_error{
  51         title: title,
  52         error: err_msg, hint: hint, source: file,
  53         start:source.start, stop:source.stop, filename:source.filename,
  54     }
  55     error(err_str, 0)
  56 
  57 -- This is a bit of a hack, but this code handles arbitrarily complex
  58 -- math expressions like 2*x + 3^2 without having to define a single
  59 -- action for every possibility.
  60 re = require 're'
  61 math_expression = re.compile [[ (([*/^+-] / [0-9]+) " ")* [*/^+-] !. ]]
  62 
  63 MAX_LINE = 80 -- For beautification purposes, try not to make lines much longer than this value
  64 compile = (tree)=>
  65     if tree == nil
  66         error("No tree was passed in.")
  67 
  68     -- Automatically upgrade trees from older versions:
  69     if tree.version and tree.version < @NOMSU_VERSION\up_to(#tree.version) and @_1_upgraded_from_2_to
  70         tree = @._1_upgraded_from_2_to(tree, tree.version, @NOMSU_VERSION)
  71 
  72     switch tree.type
  73         when "Action"
  74             stub = tree.stub
  75             compile_action = @COMPILE_RULES[stub]
  76             if not compile_action and math_expression\match(stub)
  77                 lua = LuaCode\from(tree.source)
  78                 for i,tok in ipairs tree
  79                     if type(tok) == 'string'
  80                         lua\add tok
  81                     else
  82                         tok_lua = @compile(tok)
  83                         -- TODO: this is overly eager, should be less aggressive
  84                         tok_lua\parenthesize! if tok.type == "Action"
  85                         lua\add tok_lua
  86                     lua\add " " if i < #tree
  87                 return lua
  88 
  89             if not compile_action
  90                 seen_words = {}
  91                 words = {}
  92                 for word in stub\gmatch("[^0-9 ][^ ]*")
  93                     unless seen_words[word]
  94                         seen_words[word] = true
  95                         table.insert words, word
  96                 table.sort(words)
  97                 stub2 = table.concat(words, " ")
  98                 compile_action = @COMPILE_RULES[stub2]
  99                 if compile_action
 100                     if debug.getinfo(compile_action, 'u').isvararg
 101                         stub = stub2
 102                     else compile_action = nil
 103 
 104             if compile_action
 105                 args = [arg for arg in *tree when type(arg) != "string"]
 106                 ret = compile_action(@, tree, unpack(args))
 107                 if ret == nil
 108                     info = debug.getinfo(compile_action, "S")
 109                     filename = Source\from_string(info.source).filename
 110                     fail_at tree,
 111                         ("Compile error: The compile-time action here (#{stub}) failed to return any value. "..
 112                         "Hint: Look at the implementation of (#{stub}) in #{filename}:#{info.linedefined} and make sure it's returning something.")
 113                 unless SyntaxTree\is_instance(ret)
 114                     ret.source or= tree.source
 115                     return ret
 116                 if ret != tree
 117                     return @compile(ret)
 118 
 119             lua = LuaCode\from(tree.source)
 120             lua\add((stub)\as_lua_id!,"(")
 121             for argnum, arg in ipairs tree\get_args!
 122                 arg_lua = @compile(arg)
 123                 if arg.type == "Block" and #arg > 1
 124                     arg_lua = LuaCode\from(arg.source, "(function()\n    ", arg_lua, "\nend)()")
 125                 if lua\trailing_line_len! + #arg_lua > MAX_LINE
 126                     lua\add(argnum > 1 and ",\n    " or "\n    ")
 127                 elseif argnum > 1
 128                     lua\add ", "
 129                 lua\add arg_lua
 130             lua\add ")"
 131             return lua
 132 
 133         when "MethodCall"
 134             stub = tree\get_stub!
 135             compile_action = @COMPILE_RULES[stub]
 136             if compile_action
 137                 args = tree\get_args!
 138                 ret = compile_action(@, tree, unpack(args))
 139                 if ret == nil
 140                     info = debug.getinfo(compile_action, "S")
 141                     filename = Source\from_string(info.source).filename
 142                     fail_at tree,
 143                         ("Compile error: The compile-time method here (#{stub}) failed to return any value. "..
 144                         "Hint: Look at the implementation of (#{stub}) in #{filename}:#{info.linedefined} "..
 145                         "and make sure it's returning something.")
 146                 unless SyntaxTree\is_instance(ret)
 147                     ret.source or= tree.source
 148                     return ret
 149                 if ret != tree
 150                     return @compile(ret)
 151 
 152             lua = LuaCode\from tree.source
 153             target_lua = @compile tree[1]
 154             target_text = target_lua\text!
 155             -- TODO: this parenthesizing is maybe overly conservative
 156             if not (target_text\match("^%(.*%)$") or target_text\match("^[_a-zA-Z][_a-zA-Z0-9.]*$") or
 157                 tree[1].type == "IndexChain")
 158                 target_lua\parenthesize!
 159 
 160             self_lua = #tree > 2 and "_self" or target_lua
 161             if #tree > 2
 162                 lua\add "(function(", self_lua, ")\n    "
 163             for i=2,#tree
 164                 lua\add "\n    " if i > 2
 165                 if i > 2 and i == #tree
 166                     lua\add "return "
 167                 lua\add self_lua, ":"
 168                 lua\add((tree[i].stub)\as_lua_id!,"(")
 169                 for argnum, arg in ipairs tree[i]\get_args!
 170                     arg_lua = @compile(arg)
 171                     if arg.type == "Block" and #arg > 1
 172                         arg_lua = LuaCode\from(arg.source, "(function()\n    ", arg_lua, "\nend)()")
 173                     if lua\trailing_line_len! + #arg_lua > MAX_LINE
 174                         lua\add(argnum > 1 and ",\n    " or "\n    ")
 175                     elseif argnum > 1
 176                         lua\add ", "
 177                     lua\add arg_lua
 178                 lua\add ")"
 179             if #tree > 2
 180                 lua\add "\nend)(", target_lua, ")"
 181             return lua
 182 
 183         when "EscapedNomsu"
 184             lua = LuaCode\from tree.source, "SyntaxTree{"
 185             needs_comma, i = false, 1
 186             as_lua = (x)->
 187                 if type(x) == 'number'
 188                     tostring(x)
 189                 elseif SyntaxTree\is_instance(x)
 190                     @compile(x)
 191                 elseif Source\is_instance(x)
 192                     tostring(x)\as_lua!
 193                 else x\as_lua!
 194 
 195             for k,v in pairs((SyntaxTree\is_instance(tree[1]) and tree[1].type == "EscapedNomsu" and tree) or tree[1])
 196                 entry_lua = LuaCode!
 197                 if k == i
 198                     i += 1
 199                 elseif type(k) == 'string' and match(k,"[_a-zA-Z][_a-zA-Z0-9]*")
 200                     entry_lua\add(k, "= ")
 201                 else
 202                     entry_lua\add("[", as_lua(k), "]= ")
 203                 entry_lua\add as_lua(v)
 204                 if needs_comma then lua\add ","
 205                 if lua\trailing_line_len! + #(entry_lua\match("^[\n]*")) > MAX_LINE
 206                     lua\add "\n    "
 207                 elseif needs_comma
 208                     lua\add " "
 209                 lua\add entry_lua
 210                 needs_comma = true
 211             lua\add "}"
 212             return lua
 213         
 214         when "Block"
 215             lua = LuaCode\from(tree.source)
 216             for i, line in ipairs tree
 217                 if line.type == "Error"
 218                     return @compile(line)
 219             for i, line in ipairs tree
 220                 if i > 1 then lua\add "\n"
 221                 line_lua = @compile(line)
 222                 lua\add line_lua
 223                 unless line_lua\last(1) == ";" or line_lua\last(4)\match("[^_a-zA-Z0-9]end$")
 224                     lua\add ";"
 225             return lua
 226 
 227         when "Text"
 228             if #tree == 0
 229                 return LuaCode\from(tree.source, '""')
 230             if #tree == 1 and type(tree[1]) == 'string'
 231                 return LuaCode\from(tree.source, tree[1]\as_lua!)
 232             lua = LuaCode\from(tree.source, "Text(")
 233             added = 0
 234             string_buffer = ""
 235             add_bit = (bit)->
 236                 if added > 0
 237                     if lua\trailing_line_len! + #bit > MAX_LINE
 238                         lua\add ",\n  "
 239                     else
 240                         lua\add ", "
 241                 lua\add bit
 242                 added += 1
 243 
 244             for i, bit in ipairs tree
 245                 if type(bit) == "string"
 246                     string_buffer ..= bit
 247                     continue
 248                 if string_buffer != ""
 249                     for i=1,#string_buffer,MAX_LINE
 250                         add_bit string_buffer\sub(i, i+MAX_LINE-1)\as_lua!
 251                     string_buffer = ""
 252 
 253                 bit_lua = @compile(bit)
 254                 if bit.type == "Block"
 255                     bit_lua = LuaCode\from bit.source, "a_List(function(add)",
 256                         "\n    ", bit_lua,
 257                         "\nend):joined()"
 258                 add_bit bit_lua
 259 
 260             if string_buffer != ""
 261                 for i=1,#string_buffer,MAX_LINE
 262                     add_bit string_buffer\sub(i, i+MAX_LINE-1)\as_lua!
 263                 string_buffer = ""
 264 
 265             if added == 0
 266                 return LuaCode\from(tree.source, '""')
 267             lua\add ")"
 268             return lua
 269 
 270         when "List", "Dict"
 271             typename = "a_"..tree.type
 272             if #tree == 0
 273                 return LuaCode\from tree.source, typename, "{}"
 274 
 275             lua = LuaCode\from tree.source
 276             chunks = 0
 277             i = 1
 278             while tree[i]
 279                 if tree[i].type == 'Block'
 280                     lua\add " + " if chunks > 0
 281                     lua\add typename, "(function(", (tree.type == 'List' and "add" or ("add, "..("add 1 =")\as_lua_id!)), ")"
 282                     body = @compile(tree[i])
 283                     body\declare_locals!
 284                     lua\add "\n    ", body, "\nend)"
 285                     chunks += 1
 286                     i += 1
 287                 else
 288                     lua\add " + " if chunks > 0
 289                     sep = ''
 290                     items_lua = LuaCode\from tree[i].source
 291                     while tree[i]
 292                         if tree[i].type == "Block"
 293                             break
 294                         item_lua = @compile tree[i]
 295                         if item_lua\match("^%.[a-zA-Z_]")
 296                             item_lua = item_lua\text!\sub(2)
 297                         if tree.type == 'Dict' and tree[i].type == 'Index'
 298                             item_lua = LuaCode\from tree[i].source, item_lua, "=true"
 299                         items_lua\add sep, item_lua
 300                         if tree[i].type == "Comment"
 301                             items_lua\add "\n"
 302                             sep = ''
 303                         elseif items_lua\trailing_line_len! > MAX_LINE
 304                             sep = items_lua\last(1) == ";" and "\n    " or ",\n    "
 305                         else
 306                             sep = items_lua\last(1) == ";" and " " or ", "
 307                         i += 1
 308                     if items_lua\is_multiline!
 309                         lua\add LuaCode\from items_lua.source, typename, "{\n    ", items_lua, "\n}"
 310                     else
 311                         lua\add LuaCode\from items_lua.source, typename, "{", items_lua, "}"
 312                     chunks += 1
 313             
 314             return lua
 315 
 316         when "Index"
 317             key_lua = @compile(tree[1])
 318             key_str = key_lua\match('^"([a-zA-Z_][a-zA-Z0-9_]*)"$')
 319             return if key_str and key_str\is_lua_id!
 320                 LuaCode\from tree.source, ".", key_str
 321             elseif key_lua\first(1) == "["
 322                 -- NOTE: this *must* use a space after the [ to avoid freaking out
 323                 -- Lua's parser if the inner expression is a long string. Lua
 324                 -- parses x[[[y]]] as x("[y]"), not as x["y"]
 325                 LuaCode\from tree.source, "[ ",key_lua,"]"
 326             else
 327                 LuaCode\from tree.source, "[",key_lua,"]"
 328 
 329         when "DictEntry"
 330             key = tree[1]
 331             if key.type != "Index"
 332                 key = SyntaxTree{type:"Index", source:key.source, key}
 333             return LuaCode\from tree.source, @compile(key),"=",(tree[2] and @compile(tree[2]) or "true")
 334         
 335         when "IndexChain"
 336             lua = @compile(tree[1])
 337             if lua\match("['\"}]$") or lua\match("]=*]$")
 338                 lua\parenthesize!
 339             if lua\text! == "..."
 340                 return LuaCode\from(tree.source, "select(", @compile(tree[2][1]), ", ...)")
 341             for i=2,#tree
 342                 key = tree[i]
 343                 -- TODO: remove this shim
 344                 if key.type != "Index"
 345                     key = SyntaxTree{type:"Index", source:key.source, key}
 346                 lua\add @compile(key)
 347             return lua
 348 
 349         when "Number"
 350             number = tostring(tree[1])\gsub("_", "")
 351             return LuaCode\from(tree.source, number)
 352 
 353         when "Var"
 354             if tree[1].type == "MethodCall"
 355                 return LuaCode\from(tree.source, @compile(tree[1][1]), ".", tree[1][2]\get_stub!\as_lua_id!)
 356             return LuaCode\from(tree.source, tree\as_var!\as_lua_id!)
 357 
 358         when "FileChunks"
 359             error("Can't convert FileChunks to a single block of lua, since each chunk's "..
 360                 "compilation depends on the earlier chunks")
 361         
 362         when "Comment"
 363             return LuaCode\from(tree.source, "-- ", (tree[1]\gsub('\n', '\n-- ')))
 364         
 365         when "Error"
 366             err_msg = pretty_error{
 367                 title:"Parse error"
 368                 error:tree.error, hint:tree.hint, source:tree\get_source_file!
 369                 start:tree.source.start, stop:tree.source.stop, filename:tree.source.filename
 370             }
 371             -- Coroutine yield here?
 372             error(err_msg)
 373 
 374         else
 375             error("Unknown type: #{tree.type}")
 376 
 377 return {:compile, :fail_at}