parse.y

   1 %{
   2 #include <stdio.h>
   3 #include <string.h>
   4 #include <stdlib.h>
   5
   6 #include "ast.h"
   7 #define YYSTYPE struct ast *
   8
   9 #include "y.tab.h"
  10
  11 int yylex_debug = 1;
  12 int yylex(void);
  13
  14 void yyerror(struct ast **result, const char *str)
  15 {
  16         fprintf(stderr, "error: %s\n", str);
  17 }
  18
  19 int yywrap()
  20 {
  21         return 1;
  22 }
  23
  24 %}
  25
  26 %define parse.error verbose
  27 %token INTEGER PLUS MINUS TIMES DIVIDE BOPEN BCLOSE SEMICOLON POWER CONS MODULO BINOR BINAND INVERSE
  28
  29 %parse-param { struct ast **result }
  30
  31 %right BINOR
  32 %right BINAND
  33 %nonassoc EQ NEQ LEQ LE GEQ GE
  34 %right CONS
  35 %left PLUS MINUS
  36 %left TIMES DIVIDE MODULO
  37 %right POWER
  38
  39 %%
  40
  41 start : exprs { *result = $1; } ;
  42
  43 exprs
  44         : { $$ = NULL; }
  45         | exprs expr SEMICOLON { $$ = ast_cons($2, $1); }
  46         ;
  47
  48 expr
  49         : expr BINOR expr { $$ = ast_binop($1, binor, $3); }
  50         | expr BINAND expr { $$ = ast_binop($1, binand, $3); }
  51         | expr EQ expr { $$ = ast_binop($1, eq, $3); }
  52         | expr NEQ expr { $$ = ast_binop($1, neq, $3); }
  53         | expr LEQ expr { $$ = ast_binop($1, leq, $3); }
  54         | expr LE expr { $$ = ast_binop($1, le, $3); }
  55         | expr GEQ expr { $$ = ast_binop($1, geq, $3); }
  56         | expr GE expr { $$ = ast_binop($1, ge, $3); }
  57         | expr CONS expr { $$ = ast_binop($1, cons, $3); }
  58         | expr PLUS expr { $$ = ast_binop($1, plus, $3); }
  59         | expr MINUS expr { $$ = ast_binop($1, minus, $3); }
  60         | expr TIMES expr { $$ = ast_binop($1, times, $3); }
  61         | expr DIVIDE expr { $$ = ast_binop($1, divide, $3); }
  62         | expr MODULO expr { $$ = ast_binop($1, modulo, $3); }
  63         | expr POWER expr { $$ = ast_binop($1, power, $3); }
  64         | MINUS expr { $$ = ast_unop(negate, $2); }
  65         | INVERSE expr { $$ = ast_unop(inverse, $2); }
  66         | BOPEN expr BCLOSE { $$ = $2; }
  67         | INTEGER
  68         ;