/* $NetBSD: ok_syntax1.y,v 1.1.1.3 2016/01/09 21:59:45 christos Exp $ */ %pure_parser %parse_param { int regs[26] } %parse_param { int *base } %lex_param { int *base } %{ # include # include #ifdef YYBISON #define YYSTYPE int #define YYLEX_PARAM base #define YYLEX_DECL() yylex(YYSTYPE *yylval, int *YYLEX_PARAM) #define YYERROR_DECL() yyerror(int regs[26], int *base, const char *s) int YYLEX_DECL(); static void YYERROR_DECL(); #endif %} %start list %token DIGIT LETTER %token OCT1 '\177' %token HEX1 '\xff' %token HEX2 '\xFF' %token HEX3 '\x7f' %token STR1 "\x7f\177\\\n" %token STR2 "\x7f\ \177\\\n" %token BELL '\a' %token BS '\b' %token NL '\n' %token LF '\f' %token CR '\r' %token TAB '\t' %token VT '\v' %union { char * cval; int ival; double dval; } %0 '@' %2 '~' %> '^' %< '#' %left '|' %left '&' %left '+' '-' %left '*' '/' '%' %left UMINUS /* supplies precedence for unary minus */ %% /* beginning of rules section */ list : /* empty */ | list stat '\n' | list error '\n' { yyerrok ; } ; stat : expr { printf("%d\n",$1);} | LETTER '=' expr { regs[$1] = $3; } ; expr : '(' expr ')' { $$ = $2; } | expr '+' expr { $$ = $1 + $3; } | expr '-' expr { $$ = $1 - $3; } | expr '*' expr { $$ = $1 * $3; } | expr '/' expr { $$ = $1 / $3; } | expr '%' expr { $$ = $1 % $3; } | expr '&' expr { $$ = $1 & $3; } | expr '|' expr { $$ = $1 | $3; } | '-' expr %prec UMINUS { $$ = - $2; } | LETTER { $$ = regs[$1]; } | number ; number: DIGIT { $$ = $1; (*base) = ($1==0) ? 8 : 10; } | number DIGIT { $$ = (*base) * $1 + $2; } ; %% /* start of programs */ #ifdef YYBYACC extern int YYLEX_DECL(); #endif int main (void) { int regs[26]; int base = 10; while(!feof(stdin)) { yyparse(regs, &base); } return 0; } #define UNUSED(x) ((void)(x)) static void YYERROR_DECL() { UNUSED(regs); /* %parse-param regs is not actually used here */ UNUSED(base); /* %parse-param base is not actually used here */ fprintf(stderr, "%s\n", s); } int YYLEX_DECL() { /* lexical analysis routine */ /* returns LETTER for a lower case letter, yylval = 0 through 25 */ /* return DIGIT for a digit, yylval = 0 through 9 */ /* all other characters are returned immediately */ int c; while( (c=getchar()) == ' ' ) { /* skip blanks */ } /* c is now nonblank */ if( islower( c )) { yylval->ival = (c - 'a'); return ( LETTER ); } if( isdigit( c )) { yylval->ival = (c - '0') % (*base); return ( DIGIT ); } return( c ); }