bundles/menhirLib/menhir-20120123/demos/calc/parser.mly

   1 /**************************************************************************/
   2 /*                                                                        */
   3 /*  Menhir                                                                */
   4 /*                                                                        */
   5 /*  François Pottier, INRIA Rocquencourt                                  */
   6 /*  Yann Régis-Gianas, PPS, Université Paris Diderot                      */
   7 /*                                                                        */
   8 /*  Copyright 2005-2008 Institut National de Recherche en Informatique    */
   9 /*  et en Automatique. All rights reserved. This file is distributed      */
  10 /*  under the terms of the Q Public License version 1.0, with the change  */
  11 /*  described in file LICENSE.                                            */
  12 /*                                                                        */
  13 /**************************************************************************/
  14
  15 %token <int> INT
  16 %token PLUS MINUS TIMES DIV
  17 %token LPAREN RPAREN
  18 %token EOL
  19
  20 %left PLUS MINUS        /* lowest precedence */
  21 %left TIMES DIV         /* medium precedence */
  22 %nonassoc UMINUS        /* highest precedence */
  23
  24 %start <int> main
  25
  26 %%
  27
  28 main:
  29 | e = expr EOL
  30     { e }
  31
  32 expr:
  33 | i = INT
  34     { i }
  35 | LPAREN e = expr RPAREN
  36     { e }
  37 | e1 = expr PLUS e2 = expr
  38     { e1 + e2 }
  39 | e1 = expr MINUS e2 = expr
  40     { e1 - e2 }
  41 | e1 = expr TIMES e2 = expr
  42     { e1 * e2 }
  43 | e1 = expr DIV e2 = expr
  44     { e1 / e2 }
  45 | MINUS e = expr %prec UMINUS
  46     { - e }
  47