diff options
Diffstat (limited to 'bc.y')
| -rw-r--r-- | bc.y | 291 |
1 files changed, 291 insertions, 0 deletions
@@ -0,0 +1,291 @@ +%{ +#define _XOPEN_SOURCE 700 +#define YYDEBUG 0 +#include "bc.h" +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +int yyerror(const char *); +int yylex(void); +extern FILE *yyin; +%} + +%union { + bc_expression *expr; + bc_num *num; + bc_op op; + char c; + char *string; + int truth; +} + +%token ENDOFFILE 0 +%token NEWLINE + +%token Define Break Quit Length +%token Return For If While Sqrt +%token Scale Ibase Obase Auto + +%token<string> STRING +%token<num> NUMBER +%token<c> LETTER + +%nonassoc<op> REL_OP +%right<op> ASSIGN_OP +%left<op> ADD_OP SUB_OP +%left<op> MUL_OP +%right<op> POW_OP +%nonassoc UNARY_MINUS +%nonassoc<op> INCR_DECR + +%type<expr> expression relational_expression named_expression +%type<num> statement semicolon_list return_expression statement_list + +%start program + +%% + +program + : ENDOFFILE + | input_item program +; + +input_item + : semicolon_list NEWLINE { + } + | function +; + +semicolon_list + : /* empty */ + | statement + | semicolon_list ';' statement { + bc_print(bc_eval($1)); + bc_print(bc_eval($3)); + } + | semicolon_list ';' { + bc_print(bc_eval($1)); + } +; + +statement_list + : /* empty */ + | statement + | statement_list NEWLINE + | statement_list NEWLINE statement + | statement_list ';' + | statement_list ';' statement +; + +statement + : expression { + } + | STRING { + } + | Break { + } + | Quit { + exit(0); + } + | Return { + } + | Return '(' return_expression ')' { + } + | For '(' expression ';' relational_expression ';' expression ')' statement { + } + | If '(' relational_expression ')' statement { + } + | While '(' relational_expression ')' statement { + } + | '{' statement_list '}' { + } +; + +function + : Define LETTER '(' opt_parameter_list ')' '{' NEWLINE opt_auto_define_list statement_list '}' +; + +opt_parameter_list + : /* empty */ + | parameter_list +; + +parameter_list + : LETTER + | define_list ',' LETTER +; + +opt_auto_define_list + : /* empty */ + | Auto define_list NEWLINE + | Auto define_list ';' +; + +define_list + : LETTER + | LETTER '[' ']' + | define_list ',' LETTER + | define_list ',' LETTER '[' ']' +; + +opt_argument_list + : /* empty */ + | argument_list +; + +argument_list + : expression + | LETTER '[' ']' ',' argument_list +; + +relational_expression + : expression { + $$ = $1; + } + | expression REL_OP expression { + $$ = bc_operation($2, $1, $3); + } +; + +return_expression + : /* empty */ + | expression +; + +expression + : named_expression + | NUMBER { + $$ = bc_literal($1); + } + | '(' expression ')' { + $$ = $2; + } + | LETTER '(' opt_argument_list ')' { + $$ = bc_function_call($1, NULL); + } + | SUB_OP expression %prec UNARY_MINUS { + $$ = bc_operation(NEG, $2, NULL); + } + | expression ADD_OP expression { + $$ = bc_operation(ADD, $1, $3); + } + | expression SUB_OP expression { + $$ = bc_operation(ADD, $1, $3); + } + | expression MUL_OP expression { + $$ = bc_operation($2, $1, $3); + } + | expression POW_OP expression { + $$ = bc_operation(POW, $1, $3); + } + | INCR_DECR named_expression { + $$ = bc_operation($1, $2, NULL); + } + | named_expression INCR_DECR { + $$ = bc_operation($2, $1, NULL); + } + | named_expression ASSIGN_OP expression { + $$ = bc_operation($2, $1, $3); + } + | Length '(' expression ')' { + $$ = bc_function_call('L', $3); + } + | Sqrt '(' expression ')' { + $$ = bc_function_call('R', $3); + } + | Scale '(' expression ')' { + $$ = bc_function_call('S', $3); + } +; + +named_expression + : LETTER { + $$ = bc_named($1); + } + | LETTER '[' expression ']' { + } + | Scale { + $$ = bc_named('S'); + } + | Ibase { + $$ = bc_named('I'); + } + | Obase { + $$ = bc_named('O'); + } +; +%% +static char **files; + +int yywrap(void) +{ + char *file = files[optind++]; + + if (yyin != stdin) { + fclose(yyin); + } + + if (file == NULL) { + return 1; + } + + yyin = strcmp(file, "-") ? fopen(file, "r") : stdin; + + if (yyin == NULL) { + fprintf(stderr, "bc: Couldn't open %s: %s\n", file, strerror(errno)); + exit(1); + } + + bc_lineno = 1; + bc_char = 1; + + return 0; +} + +int yyerror(const char *str) +{ + if (!feof(yyin)) { + fprintf(stderr, "%s at line %d, character %d\n", str, bc_lineno, bc_char); + } + + if (isatty(fileno(yyin))) { + /* recover */ + return 1; + } + + exit(1); +} + +int main(int argc, char *argv[]) +{ + int c; + while ((c = getopt(argc, argv, "l")) != -1) { + switch (c) { + case 'l': /** enable math functions and set /scale/ to 20 **/ + /* set scale = 20 */ + /* load math functions */ + break; + + default: + return 1; + } + } + + #if YYDEBUG == 1 + yydebug = 1; + #endif + + yyin = stdin; + + if (argv[optind] != NULL) { + files = argv; + yywrap(); + } + + return yyparse(); +} + +int bc_lineno = 1; +int bc_char = 1; |