Hello,
I received Broken pipe error when compiling evaluator.y (in the
attachment of this message) file with bison 20030307-1:
$ bison evaluator.y
evaluator.y: conflicts: 14 shift/reduce
Broken pipe
With bison 1.875-1 it is OK, i.e. there is no error and file
seems to be translated to evaluator.tab.c correctly.
With greetings
Pavel Kudrna.
/* This is the evaluator */
%{
#include <math.h> /* For math functions, cos(), sin(), etc. */
#include "evaluator.h" /* Contains definition of `symrec' */
%}
%union {
float val; /* For returning numbers. */
symrec *tptr; /* For returning symbol-table pointers */
float *indirect_val; /* For using external data */
}
%token <val> NUM /* Simple float precision number */
%token <tptr> VAR FNCT IVAR /* Variable and Function */
%type <val> exp
%right '='
%left '-' '+'
%left '*' '/'
%left NEG /* Negation--unary minus */
%right '^' /* Exponentiation */
/* Grammar follows */
%%
input: /* empty */
| input line
;
line:
'\n'
| exp '\n' { EVAL_RESULT=$1; }
| error '\n' { yyerrok; }
;
exp: NUM { $$ = $1; }
| VAR { $$ = $1->value.var; }
| IVAR { $$ = *($1->value.ivar); }
| VAR '=' exp { $$ = $3; $1->value.var = $3; }
| IVAR '=' exp { $$ = *($1->value.ivar) = $3; }
| FNCT '(' exp ')' { $$ = (*($1->value.fnctptr))($3); }
| FNCT '(' exp ',' exp ')' { $$ = (*($1->value.fnctptr))($3,$5); }
| FNCT '(' exp ',' exp ',' exp ')' { $$ =
(*($1->value.fnctptr))($3,$5,$7); }
| FNCT '(' exp ',' exp ',' exp ',' exp ')' { $$ =
(*($1->value.fnctptr))($3,$5,$7,$9); }
| FNCT '(' exp ',' exp ',' exp ',' exp ',' exp')' { $$ =
(*($1->value.fnctptr))($3,$5,$7,$9,$11); }
| FNCT '(' exp ',' exp ',' exp ',' exp ',' exp ',' exp')' { $$ =
(*($1->value.fnctptr))($3,$5,$7,$9,$11,$13); }
| exp '+' exp { $$ = $1 + $3; }
| exp '-' exp { $$ = $1 - $3; }
| exp '*' exp { $$ = $1 * $3; }
| exp '/' exp { $$ = $1 / $3; }
| exp '%' exp { $$ = fmod($1,$3); }
| '-' exp %prec NEG { $$ = -$2; }
| exp '^' exp { $$ = pow ($1, $3); }
| '(' exp ')' { $$ = $2; }
;
/* End of grammar */
%%
/* HERE BEGINS THE CODE FOR THE SYMOL TABLE */
#include <string.h>
struct init_func
{
char *fname;
float (*fnct)();
};
struct init_var
{
char *vname;
float value;
};
struct init_func arith_fncts[]
= {
"sin", SINW,
"cos", COSW,
"atan", ATANW,
"ln", LOGW,
"exp", EXPW,
"sqrt", SQRTW,
"pow", POWW,
"step",step,
"pulse",pulse,
"ramp",ramp,
0, 0
};
struct init_var init_vars[] = {
"PI", 3.141592654,
/* "e", 2.18281828, ! bad constant */
"e", 2.718281828,
0,0
};
/* The symbol table: a chain of `struct symrec'. */
symrec *init_table (symrec *symbol_table) /* puts arithmetic functions in table. */
{
int i;
for (i = 0; arith_fncts[i].fname != 0; i++)
{
symbol_table = putsym (symbol_table,arith_fncts[i].fname, FNCT);
symbol_table->value.fnctptr = arith_fncts[i].fnct;
}
for (i = 0; init_vars[i].vname !=0; i++)
{
symbol_table = putsym (symbol_table,
init_vars[i].vname,VAR);
symbol_table->value.var = init_vars[i].value;
}
return symbol_table;
}
void delete_table (symrec *symbol_table) /* puts arithmetic functions in table. */
{
int i;
symrec *ptr,*old;
for(ptr=symbol_table;ptr!=(symrec *)0;
old=ptr,ptr=(symrec *) ptr->next,free(old->name),free(old));
}
symrec *
putsym (symrec *sym_table,char *sym_name,int sym_type)
{
symrec *ptr;
ptr = (symrec *) malloc (sizeof (symrec));
ptr->name = (char *) malloc (strlen (sym_name) + 1);
strcpy (ptr->name,sym_name);
ptr->type = sym_type;
ptr->value.var = 0; /* set value to 0 even if fctn. */
ptr->next = (struct symrec *)sym_table;
return ptr;
}
symrec *
getsym (symrec *sym_table,char *sym_name)
{
symrec *ptr;
for (ptr = sym_table; ptr != (symrec *) 0;
ptr = (symrec *)ptr->next)
if (strcmp (ptr->name,sym_name) == 0)
return ptr;
return 0;
}
/* THIS IS THE LEXER */
/* Some helper functions for the lexer */
int Sindex;
char *EVAL_STRING;
float EVAL_RESULT;
symrec *SYMBOL_TABLE;
char Sgetchar() {
Sindex++;
return EVAL_STRING[(Sindex-1)];
}
void Sungetc() {
Sindex--;
}
float Sgetnum() {
float value;
char c;
sscanf(EVAL_STRING + Sindex,"%f",&value);
do {
Sindex++;
c=EVAL_STRING[Sindex];
} while( isdigit(c) || c==0 || c=='e' || c=='E'
|| c=='.'
|| ((c=='-'||c=='+') &&
(EVAL_STRING[Sindex-1]=='e' ||
EVAL_STRING[Sindex-1]=='E'))
);
return value;
}
#include <stdio.h>
yylex ()
{
int c;
/* Ignore whitespace, get first nonwhite character. */
while ((c = Sgetchar ()) == ' ' || c == '\t');
if (c == 0)
return 0;
/* Char starts a number => parse the number. */
if (c == '.' || isdigit (c))
{
Sungetc ();
yylval.val=Sgetnum();
return NUM;
}
/* Char starts an identifier => read the name. */
if (isalpha (c))
{
symrec *s;
static char *symbuf = 0;
static int length = 0;
int i;
/* Initially make the buffer long enough
for a 40-character symbol name. */
if (length == 0)
length = 40, symbuf = (char *)malloc (length + 1);
i = 0;
do
{
/* If buffer is full, make it bigger. */
if (i == length)
{
length *= 2;
symbuf = (char *)realloc (symbuf, length + 1);
}
/* Add this character to the buffer. */
symbuf[i++] = c;
/* Get another character. */
c = Sgetchar ();
}
while (c != 0 && (isalnum (c)|| c=='_'));
Sungetc ();
symbuf[i] = '\0';
s = getsym (SYMBOL_TABLE,symbuf);
if (s == 0)
s=SYMBOL_TABLE = putsym (SYMBOL_TABLE,symbuf, VAR);
yylval.tptr = s;
return s->type;
}
/* Any other character is a token by itself. */
return c;
}
/* THIS IS THE MAIN */
/* main ()
{
init_table ();
yyparse ();
} */
yyerror (s) /* Called by yyparse on error */
char *s;
{
printf ("%s: %s\n", s,EVAL_STRING);
exit(1); /* DIE! DIE! DIE! */
}
/* THE END */
--
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