1 /* $NetBSD: quote_calc.y,v 1.1.1.1 2013/04/06 14:45:30 christos Exp $ */ 2 3 %{ 4 # include <stdio.h> 5 # include <ctype.h> 6 7 int regs[26]; 8 int base; 9 10 int yylex(void); 11 static void yyerror(const char *s); 12 13 %} 14 15 %start list 16 17 %token OP_ADD "ADD" 18 %token OP_SUB "SUB" 19 %token OP_MUL "MUL" 20 %token OP_DIV "DIV" 21 %token OP_MOD "MOD" 22 %token OP_AND "AND" 23 24 %token DIGIT LETTER 25 26 %left '|' 27 %left '&' 28 %left '+' '-' 29 %left '*' '/' '%' 30 %left UMINUS /* supplies precedence for unary minus */ 31 32 %% /* beginning of rules section */ 33 34 list : /* empty */ 35 | list stat '\n' 36 | list error '\n' 37 { yyerrok ; } 38 ; 39 40 stat : expr 41 { printf("%d\n",$1);} 42 | LETTER '=' expr 43 { regs[$1] = $3; } 44 ; 45 46 expr : '(' expr ')' 47 { $$ = $2; } 48 | expr OP_ADD expr 49 { $$ = $1 + $3; } 50 | expr OP_SUB expr 51 { $$ = $1 - $3; } 52 | expr OP_MUL expr 53 { $$ = $1 * $3; } 54 | expr OP_DIV expr 55 { $$ = $1 / $3; } 56 | expr OP_MOD expr 57 { $$ = $1 % $3; } 58 | expr OP_AND expr 59 { $$ = $1 & $3; } 60 | expr '|' expr 61 { $$ = $1 | $3; } 62 | OP_SUB expr %prec UMINUS 63 { $$ = - $2; } 64 | LETTER 65 { $$ = regs[$1]; } 66 | number 67 ; 68 69 number: DIGIT 70 { $$ = $1; base = ($1==0) ? 8 : 10; } 71 | number DIGIT 72 { $$ = base * $1 + $2; } 73 ; 74 75 %% /* start of programs */ 76 77 int 78 main (void) 79 { 80 while(!feof(stdin)) { 81 yyparse(); 82 } 83 return 0; 84 } 85 86 static void yyerror(const char * s)87yyerror(const char *s) 88 { 89 fprintf(stderr, "%s\n", s); 90 } 91 92 int yylex(void)93yylex(void) { 94 /* lexical analysis routine */ 95 /* returns LETTER for a lower case letter, yylval = 0 through 25 */ 96 /* return DIGIT for a digit, yylval = 0 through 9 */ 97 /* all other characters are returned immediately */ 98 99 int c; 100 101 while( (c=getchar()) == ' ' ) { /* skip blanks */ } 102 103 /* c is now nonblank */ 104 105 if( islower( c )) { 106 yylval = c - 'a'; 107 return ( LETTER ); 108 } 109 if( isdigit( c )) { 110 yylval = c - '0'; 111 return ( DIGIT ); 112 } 113 return( c ); 114 } 115