mlton/front-end/front-end.fun

   1 (* Copyright (C) 2015 Matthew Fluet.
   2  * Copyright (C) 1999-2006 Henry Cejtin, Matthew Fluet, Suresh
   3  *    Jagannathan, and Stephen Weeks.
   4  * Copyright (C) 1997-2000 NEC Research Institute.
   5  *
   6  * MLton is released under a BSD-style license.
   7  * See the file MLton-LICENSE for details.
   8  *)
   9
  10 functor FrontEnd (S: FRONT_END_STRUCTS): FRONT_END =
  11 struct
  12
  13 open S
  14
  15 structure LrVals = MLLrValsFun (structure Token = LrParser.Token
  16                                 structure Ast = Ast)
  17 structure Lex = MLLexFun (structure Tokens = LrVals.Tokens)
  18 structure Parse = JoinWithArg (structure ParserData = LrVals.ParserData
  19                                structure Lex = Lex
  20                                structure LrParser = LrParser)
  21
  22 fun lexAndParse (source: Source.t, ins: In.t): Ast.Program.t =
  23    let
  24       val stream =
  25          Parse.makeLexer (fn n => In.inputN (ins, n))
  26          {source = source}
  27       val lookahead = 30
  28       val result =
  29          (#1 (Parse.parse (lookahead, stream, fn (s, left, right) =>
  30                            Control.errorStr (Region.make {left = left,
  31                                                           right = right},
  32                                              s),
  33                            ())))
  34          handle _ =>
  35             let
  36                val i = Source.lineStart source
  37                val _ =
  38                   Control.errorStr (Region.make {left = i, right = i},
  39                                     "parse error")
  40             in
  41                Ast.Program.T []
  42             end
  43       val () = Ast.Program.checkSyntax result
  44
  45       (* Outputs AST to a file if Control.keepAST is true *)
  46       val () =
  47          if !Control.keepAST
  48             then File.withAppend
  49                  (concat [!Control.inputFile, ".ast"], fn outputStream =>
  50                   (Out.outputl (outputStream, concat ["File: ", Source.name source]);
  51                    Layout.output (Ast.Program.layout result, outputStream);
  52                    Out.newline outputStream;
  53                    Out.newline outputStream))
  54             else ()
  55    in
  56       result
  57    end
  58
  59 fun lexAndParseFile (f: File.t) =
  60    File.withIn
  61    (f, fn ins => lexAndParse (Source.new f, ins))
  62
  63 val lexAndParseFile =
  64     Trace.trace ("FrontEnd.lexAndParseFile", File.layout, Ast.Program.layout)
  65     lexAndParseFile
  66
  67 end