ocamlsexp/parser.mly

   1 %{
   2   (* File: parser.mly
   3
   4       Copyright (C) 2005-
   5
   6         Jane Street Holding, LLC
   7         Author: Markus Mottl
   8         email: mmottl@janestcapital.com
   9         WWW: http://www.janestcapital.com/ocaml
  10
  11      This library is free software; you can redistribute it and/or
  12      modify it under the terms of the GNU Lesser General Public
  13      License as published by the Free Software Foundation; either
  14      version 2 of the License, or (at your option) any later version.
  15
  16      This library is distributed in the hope that it will be useful,
  17      but WITHOUT ANY WARRANTY; without even the implied warranty of
  18      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19      Lesser General Public License for more details.
  20
  21      You should have received a copy of the GNU Lesser General Public
  22      License along with this library; if not, write to the Free Software
  23      Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  24   *)
  25
  26   (** Parser: Grammar Specification for Parsing S-expressions *)
  27
  28   open Lexing
  29
  30   let parse_failure what =
  31     let pos = symbol_start_pos () in
  32     let msg =
  33       Printf.sprintf "Sexplib.Parser: failed to parse line %d char %d: %s"
  34         pos.pos_lnum (pos.pos_cnum - pos.pos_bol) what in
  35     failwith msg
  36 %}
  37
  38 %token <string> STRING
  39 %token LPAREN RPAREN EOF
  40
  41 %start sexp
  42 %type <Type.t> sexp
  43
  44 %start sexp_opt
  45 %type <Type.t option> sexp_opt
  46
  47 %start sexps
  48 %type <Type.t list> sexps
  49
  50 %start rev_sexps
  51 %type <Type.t list> rev_sexps
  52
  53 %%
  54
  55 sexp
  56   : STRING { Type.Atom $1 }
  57   | LPAREN RPAREN { Type.List [] }
  58   | LPAREN rev_sexps_aux RPAREN { Type.List (List.rev $2) }
  59   | error { parse_failure "sexp" }
  60
  61 sexp_opt
  62   : sexp { Some $1 }
  63   | EOF { None }
  64
  65 rev_sexps_aux
  66   : sexp { [$1] }
  67   | rev_sexps_aux sexp { $2 :: $1 }
  68
  69 rev_sexps
  70   : rev_sexps_aux { $1 }
  71   | EOF { [] }
  72
  73 sexps
  74   : rev_sexps_aux { List.rev $1 }
  75   | EOF { [] }