247 lines
6.2 KiB
Text
247 lines
6.2 KiB
Text
%{
|
|
|
|
/*
|
|
* (C) Copyright 2014, Stephen M. Cameron.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <math.h>
|
|
|
|
struct parser_value_type {
|
|
double dval;
|
|
long long ival;
|
|
int has_dval;
|
|
int has_error;
|
|
};
|
|
|
|
typedef union valtype {
|
|
struct parser_value_type v;
|
|
} PARSER_VALUE_TYPE;
|
|
|
|
#define YYSTYPE PARSER_VALUE_TYPE
|
|
|
|
int yyerror(__attribute__((unused)) long long *result,
|
|
__attribute__((unused)) double *dresult,
|
|
__attribute__((unused)) int *has_error,
|
|
__attribute__((unused)) int *units_specified,
|
|
__attribute__((unused)) const char *msg);
|
|
|
|
extern int yylex(void);
|
|
extern void yyrestart(FILE *file);
|
|
extern int lexer_value_is_time;
|
|
|
|
%}
|
|
|
|
%union valtype {
|
|
struct parser_value_type {
|
|
double dval;
|
|
long long ival;
|
|
int has_dval;
|
|
int has_error;
|
|
} v;
|
|
};
|
|
|
|
%token <v> NUMBER
|
|
%token <v> BYE
|
|
%token <v> SUFFIX
|
|
%left '-' '+'
|
|
%right SUFFIX
|
|
%left '*' '/'
|
|
%right '^'
|
|
%left '%'
|
|
%nonassoc UMINUS
|
|
%parse-param { long long *result }
|
|
%parse-param { double *dresult }
|
|
%parse-param { int *has_error }
|
|
%parse-param { int *units_specified }
|
|
|
|
%type <v> expression
|
|
%%
|
|
|
|
top_level: expression {
|
|
*result = $1.ival;
|
|
*dresult = $1.dval;
|
|
*has_error = $1.has_error;
|
|
}
|
|
| expression error {
|
|
*result = $1.ival;
|
|
*dresult = $1.dval;
|
|
*has_error = 1;
|
|
}
|
|
expression: expression '+' expression {
|
|
if (!$1.has_dval && !$3.has_dval)
|
|
$$.ival = $1.ival + $3.ival;
|
|
else
|
|
$$.ival = (long long) ($1.dval + $3.dval);
|
|
$$.dval = $1.dval + $3.dval;
|
|
$$.has_error = $1.has_error || $3.has_error;
|
|
}
|
|
| expression '-' expression {
|
|
if (!$1.has_dval && !$3.has_dval)
|
|
$$.ival = $1.ival - $3.ival;
|
|
else
|
|
$$.ival = (long long) ($1.dval - $3.dval);
|
|
$$.dval = $1.dval - $3.dval;
|
|
$$.has_error = $1.has_error || $3.has_error;
|
|
}
|
|
| expression '*' expression {
|
|
if (!$1.has_dval && !$3.has_dval)
|
|
$$.ival = $1.ival * $3.ival;
|
|
else
|
|
$$.ival = (long long) ($1.dval * $3.dval);
|
|
$$.dval = $1.dval * $3.dval;
|
|
$$.has_error = $1.has_error || $3.has_error;
|
|
}
|
|
| expression '/' expression {
|
|
if ($3.ival == 0)
|
|
yyerror(0, 0, 0, 0, "divide by zero");
|
|
else
|
|
$$.ival = $1.ival / $3.ival;
|
|
if ($3.dval < 1e-20 && $3.dval > -1e-20)
|
|
yyerror(0, 0, 0, 0, "divide by zero");
|
|
else
|
|
$$.dval = $1.dval / $3.dval;
|
|
if ($3.has_dval || $1.has_dval)
|
|
$$.ival = (long long) $$.dval;
|
|
$$.has_error = $1.has_error || $3.has_error;
|
|
}
|
|
| '-' expression %prec UMINUS {
|
|
$$.ival = -$2.ival;
|
|
$$.dval = -$2.dval;
|
|
$$.has_error = $2.has_error;
|
|
}
|
|
| '(' expression ')' { $$ = $2; }
|
|
| expression SUFFIX {
|
|
if (!$1.has_dval && !$2.has_dval)
|
|
$$.ival = $1.ival * $2.ival;
|
|
else
|
|
$$.ival = (long long) $1.dval * $2.dval;
|
|
if ($1.has_dval || $2.has_dval)
|
|
$$.dval = $1.dval * $2.dval;
|
|
else
|
|
$$.dval = $1.ival * $2.ival;
|
|
$$.has_error = $1.has_error || $2.has_error;
|
|
*units_specified = 1;
|
|
}
|
|
| expression '%' expression {
|
|
if ($1.has_dval || $3.has_dval)
|
|
yyerror(0, 0, 0, 0, "modulo on floats");
|
|
if ($3.ival == 0)
|
|
yyerror(0, 0, 0, 0, "divide by zero");
|
|
else {
|
|
$$.ival = $1.ival % $3.ival;
|
|
$$.dval = $$.ival;
|
|
}
|
|
$$.has_error = $1.has_error || $3.has_error;
|
|
}
|
|
| expression '^' expression {
|
|
$$.has_error = $1.has_error || $3.has_error;
|
|
if (!$1.has_dval && !$3.has_dval) {
|
|
int i;
|
|
|
|
if ($3.ival == 0) {
|
|
$$.ival = 1;
|
|
} else if ($3.ival > 0) {
|
|
long long tmp = $1.ival;
|
|
$$.ival = 1.0;
|
|
for (i = 0; i < $3.ival; i++)
|
|
$$.ival *= tmp;
|
|
} else {
|
|
/* integers, 2^-3, ok, we now have doubles */
|
|
double tmp;
|
|
if ($1.ival == 0 && $3.ival == 0) {
|
|
tmp = 1.0;
|
|
$$.has_error = 1;
|
|
} else {
|
|
double x = (double) $1.ival;
|
|
double y = (double) $3.ival;
|
|
tmp = pow(x, y);
|
|
}
|
|
$$.ival = (long long) tmp;
|
|
}
|
|
$$.dval = pow($1.dval, $3.dval);
|
|
} else {
|
|
$$.dval = pow($1.dval, $3.dval);
|
|
$$.ival = (long long) $$.dval;
|
|
}
|
|
}
|
|
| NUMBER { $$ = $1; };
|
|
%%
|
|
#include <stdio.h>
|
|
|
|
/* Urgh. yacc and lex are kind of horrible. This is not thread safe, obviously. */
|
|
static int lexer_read_offset = 0;
|
|
static char lexer_input_buffer[1000];
|
|
|
|
int lexer_input(char* buffer, unsigned int *bytes_read, int bytes_requested)
|
|
{
|
|
int bytes_left = strlen(lexer_input_buffer) - lexer_read_offset;
|
|
|
|
if (bytes_requested > bytes_left )
|
|
bytes_requested = bytes_left;
|
|
memcpy(buffer, &lexer_input_buffer[lexer_read_offset], bytes_requested);
|
|
*bytes_read = bytes_requested;
|
|
lexer_read_offset += bytes_requested;
|
|
return 0;
|
|
}
|
|
|
|
static void setup_to_parse_string(const char *string)
|
|
{
|
|
unsigned int len;
|
|
|
|
len = strlen(string);
|
|
if (len > sizeof(lexer_input_buffer) - 3)
|
|
len = sizeof(lexer_input_buffer) - 3;
|
|
|
|
strncpy(lexer_input_buffer, string, len);
|
|
lexer_input_buffer[len] = '\0';
|
|
lexer_input_buffer[len + 1] = '\0'; /* lex/yacc want string double null terminated! */
|
|
lexer_read_offset = 0;
|
|
}
|
|
|
|
int evaluate_arithmetic_expression(const char *buffer, long long *ival, double *dval,
|
|
double implied_units, int is_time)
|
|
{
|
|
int rc, units_specified = 0, has_error = 0;
|
|
|
|
lexer_value_is_time = is_time;
|
|
setup_to_parse_string(buffer);
|
|
rc = yyparse(ival, dval, &has_error, &units_specified);
|
|
yyrestart(NULL);
|
|
if (rc || has_error) {
|
|
*ival = 0;
|
|
*dval = 0;
|
|
has_error = 1;
|
|
}
|
|
if (!units_specified) {
|
|
*ival = (int) ((double) *ival * implied_units);
|
|
*dval = *dval * implied_units;
|
|
}
|
|
return has_error;
|
|
}
|
|
|
|
int yyerror(__attribute__((unused)) long long *result,
|
|
__attribute__((unused)) double *dresult,
|
|
__attribute__((unused)) int *has_error,
|
|
__attribute__((unused)) int *units_specified,
|
|
__attribute__((unused)) const char *msg)
|
|
{
|
|
/* We do not need to do anything here. */
|
|
return 0;
|
|
}
|
|
|