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Diffstat (limited to 'contrib/byacc/test/quote_calc2.y')
-rw-r--r-- | contrib/byacc/test/quote_calc2.y | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/contrib/byacc/test/quote_calc2.y b/contrib/byacc/test/quote_calc2.y new file mode 100644 index 0000000..ab72a28 --- /dev/null +++ b/contrib/byacc/test/quote_calc2.y @@ -0,0 +1,112 @@ +%{ +# include <stdio.h> +# include <ctype.h> + +int regs[26]; +int base; + +int yylex(void); +static void yyerror(const char *s); + +%} + +%start list + +%token OP_ADD "ADD" +%token OP_SUB "SUB" +%token OP_MUL "MUL" +%token OP_DIV "DIV" +%token OP_MOD "MOD" +%token OP_AND "AND" + +%token DIGIT LETTER + +%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 ')' + { $$ = $2; } + | expr "ADD" expr + { $$ = $1 + $3; } + | expr "SUB" expr + { $$ = $1 - $3; } + | expr "MUL" expr + { $$ = $1 * $3; } + | expr "DIV" expr + { $$ = $1 / $3; } + | expr "MOD" expr + { $$ = $1 % $3; } + | expr "AND" expr + { $$ = $1 & $3; } + | expr '|' expr + { $$ = $1 | $3; } + | "SUB" expr %prec UMINUS + { $$ = - $2; } + | LETTER + { $$ = regs[$1]; } + | number + ; + +number: DIGIT + { $$ = $1; base = ($1==0) ? 8 : 10; } + | number DIGIT + { $$ = base * $1 + $2; } + ; + +%% /* start of programs */ + +int +main (void) +{ + while(!feof(stdin)) { + yyparse(); + } + return 0; +} + +static void +yyerror(const char *s) +{ + fprintf(stderr, "%s\n", s); +} + +int +yylex(void) { + /* 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 = c - 'a'; + return ( LETTER ); + } + if( isdigit( c )) { + yylval = c - '0'; + return ( DIGIT ); + } + return( c ); +} |