arith.c

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    }

  if (yychar <= YYEOF)
    {
      yychar = yytoken = YYEOF;
      YYDPRINTF ((stderr, "Now at end of input.\n"));
    }
  else
    {
      yytoken = YYTRANSLATE (yychar);
      YYDSYMPRINTF ("Next token is", yytoken, &yylval, &yylloc);
    }

  /* If the proper action on seeing token YYTOKEN is to reduce or to
     detect an error, take that action.  */
  yyn += yytoken;
  if (yyn < 0 || YYLAST < yyn || yycheck[yyn] != yytoken)
    goto yydefault;
  yyn = yytable[yyn];
  if (yyn <= 0)
    {
      if (yyn == 0 || yyn == YYTABLE_NINF)
	goto yyerrlab;
      yyn = -yyn;
      goto yyreduce;
    }

  if (yyn == YYFINAL)
    YYACCEPT;

  /* Shift the lookahead token.  */
  YYDPRINTF ((stderr, "Shifting token %s, ", yytname[yytoken]));

  /* Discard the token being shifted unless it is eof.  */
  if (yychar != YYEOF)
    yychar = YYEMPTY;

  *++yyvsp = yylval;


  /* Count tokens shifted since error; after three, turn off error
     status.  */
  if (yyerrstatus)
    yyerrstatus--;

  yystate = yyn;
  goto yynewstate;


/*-----------------------------------------------------------.
| yydefault -- do the default action for the current state.  |
`-----------------------------------------------------------*/
yydefault:
  yyn = yydefact[yystate];
  if (yyn == 0)
    goto yyerrlab;
  goto yyreduce;


/*-----------------------------.
| yyreduce -- Do a reduction.  |
`-----------------------------*/
yyreduce:
  /* yyn is the number of a rule to reduce with.  */
  yylen = yyr2[yyn];

  /* If YYLEN is nonzero, implement the default value of the action:
     `$$ = $1'.

     Otherwise, the following line sets YYVAL to garbage.
     This behavior is undocumented and Bison
     users should not rely upon it.  Assigning to YYVAL
     unconditionally makes the parser a bit smaller, and it avoids a
     GCC warning that YYVAL may be used uninitialized.  */
  yyval = yyvsp[1-yylen];


  YY_REDUCE_PRINT (yyn);
  switch (yyn)
    {
        case 2:
#line 76 "arith.y"
    {
			return (yyvsp[0]);
		;}
    break;

  case 3:
#line 82 "arith.y"
    { yyval = yyvsp[-1]; ;}
    break;

  case 4:
#line 83 "arith.y"
    { yyval = yyvsp[-2] ? yyvsp[-2] : yyvsp[0] ? yyvsp[0] : 0; ;}
    break;

  case 5:
#line 84 "arith.y"
    { yyval = yyvsp[-2] ? ( yyvsp[0] ? yyvsp[0] : 0 ) : 0; ;}
    break;

  case 6:
#line 85 "arith.y"
    { yyval = yyvsp[-2] | yyvsp[0]; ;}
    break;

  case 7:
#line 86 "arith.y"
    { yyval = yyvsp[-2] ^ yyvsp[0]; ;}
    break;

  case 8:
#line 87 "arith.y"
    { yyval = yyvsp[-2] & yyvsp[0]; ;}
    break;

  case 9:
#line 88 "arith.y"
    { yyval = yyvsp[-2] == yyvsp[0]; ;}
    break;

  case 10:
#line 89 "arith.y"
    { yyval = yyvsp[-2] > yyvsp[0]; ;}
    break;

  case 11:
#line 90 "arith.y"
    { yyval = yyvsp[-2] >= yyvsp[0]; ;}
    break;

  case 12:
#line 91 "arith.y"
    { yyval = yyvsp[-2] < yyvsp[0]; ;}
    break;

  case 13:
#line 92 "arith.y"
    { yyval = yyvsp[-2] <= yyvsp[0]; ;}
    break;

  case 14:
#line 93 "arith.y"
    { yyval = yyvsp[-2] != yyvsp[0]; ;}
    break;

  case 15:
#line 94 "arith.y"
    { yyval = yyvsp[-2] << yyvsp[0]; ;}
    break;

  case 16:
#line 95 "arith.y"
    { yyval = yyvsp[-2] >> yyvsp[0]; ;}
    break;

  case 17:
#line 96 "arith.y"
    { yyval = yyvsp[-2] + yyvsp[0]; ;}
    break;

  case 18:
#line 97 "arith.y"
    { yyval = yyvsp[-2] - yyvsp[0]; ;}
    break;

  case 19:
#line 98 "arith.y"
    { yyval = yyvsp[-2] * yyvsp[0]; ;}
    break;

  case 20:
#line 99 "arith.y"
    {
			if (yyvsp[0] == 0)
				yyerror("division by zero");
			yyval = yyvsp[-2] / yyvsp[0];
			;}
    break;

  case 21:
#line 104 "arith.y"
    {
			if (yyvsp[0] == 0)
				yyerror("division by zero");
			yyval = yyvsp[-2] % yyvsp[0];
			;}
    break;

  case 22:
#line 109 "arith.y"
    { yyval = !(yyvsp[0]); ;}
    break;

  case 23:
#line 110 "arith.y"
    { yyval = ~(yyvsp[0]); ;}
    break;

  case 24:
#line 111 "arith.y"
    { yyval = -(yyvsp[0]); ;}
    break;

  case 25:
#line 112 "arith.y"
    { yyval = yyvsp[0]; ;}
    break;


    }

/* Line 1010 of yacc.c.  */
#line 1276 "arith.c"

  yyvsp -= yylen;
  yyssp -= yylen;


  YY_STACK_PRINT (yyss, yyssp);

  *++yyvsp = yyval;


  /* Now `shift' the result of the reduction.  Determine what state
     that goes to, based on the state we popped back to and the rule
     number reduced by.  */

  yyn = yyr1[yyn];

  yystate = yypgoto[yyn - YYNTOKENS] + *yyssp;
  if (0 <= yystate && yystate <= YYLAST && yycheck[yystate] == *yyssp)
    yystate = yytable[yystate];
  else
    yystate = yydefgoto[yyn - YYNTOKENS];

  goto yynewstate;


/*------------------------------------.
| yyerrlab -- here on detecting error |
`------------------------------------*/
yyerrlab:
  /* If not already recovering from an error, report this error.  */
  if (!yyerrstatus)
    {
      ++yynerrs;
#if YYERROR_VERBOSE
      yyn = yypact[yystate];

      if (YYPACT_NINF < yyn && yyn < YYLAST)
	{
	  YYSIZE_T yysize = 0;
	  int yytype = YYTRANSLATE (yychar);
	  const char* yyprefix;
	  char *yymsg;
	  int yyx;

	  /* Start YYX at -YYN if negative to avoid negative indexes in
	     YYCHECK.  */
	  int yyxbegin = yyn < 0 ? -yyn : 0;

	  /* Stay within bounds of both yycheck and yytname.  */
	  int yychecklim = YYLAST - yyn;
	  int yyxend = yychecklim < YYNTOKENS ? yychecklim : YYNTOKENS;
	  int yycount = 0;

	  yyprefix = ", expecting ";
	  for (yyx = yyxbegin; yyx < yyxend; ++yyx)
	    if (yycheck[yyx + yyn] == yyx && yyx != YYTERROR)
	      {
		yysize += yystrlen (yyprefix) + yystrlen (yytname [yyx]);
		yycount += 1;
		if (yycount == 5)
		  {
		    yysize = 0;
		    break;
		  }
	      }
	  yysize += (sizeof ("syntax error, unexpected ")
		     + yystrlen (yytname[yytype]));
	  yymsg = (char *) YYSTACK_ALLOC (yysize);
	  if (yymsg != 0)
	    {
	      char *yyp = yystpcpy (yymsg, "syntax error, unexpected ");
	      yyp = yystpcpy (yyp, yytname[yytype]);

	      if (yycount < 5)
		{
		  yyprefix = ", expecting ";
		  for (yyx = yyxbegin; yyx < yyxend; ++yyx)
		    if (yycheck[yyx + yyn] == yyx && yyx != YYTERROR)
		      {
			yyp = yystpcpy (yyp, yyprefix);
			yyp = yystpcpy (yyp, yytname[yyx]);
			yyprefix = " or ";
		      }
		}
	      yyerror (yymsg);
	      YYSTACK_FREE (yymsg);
	    }
	  else
	    yyerror ("syntax error; also virtual memory exhausted");
	}
      else
#endif /* YYERROR_VERBOSE */
	yyerror ("syntax error");
    }



  if (yyerrstatus == 3)
    {
      /* If just tried and failed to reuse lookahead token after an
	 error, discard it.  */

      if (yychar <= YYEOF)
        {
          /* If at end of input, pop the error token,
	     then the rest of the stack, then return failure.  */
	  if (yychar == YYEOF)
	     for (;;)
	       {
		 YYPOPSTACK;
		 if (yyssp == yyss)
		   YYABORT;
		 YYDSYMPRINTF ("Error: popping", yystos[*yyssp], yyvsp, yylsp);
		 yydestruct (yystos[*yyssp], yyvsp);
	       }
        }
      else
	{
	  YYDSYMPRINTF ("Error: discarding", yytoken, &yylval, &yylloc);
	  yydestruct (yytoken, &yylval);
	  yychar = YYEMPTY;

	}
    }

  /* Else will try to reuse lookahead token after shifting the error
     token.  */
  goto yyerrlab1;


/*---------------------------------------------------.
| yyerrorlab -- error raised explicitly by YYERROR.  |
`---------------------------------------------------*/
yyerrorlab:

#ifdef __GNUC__
  /* Pacify GCC when the user code never invokes YYERROR and the label
     yyerrorlab therefore never appears in user code.  */
  if (0)
     goto yyerrorlab;
#endif

  yyvsp -= yylen;
  yyssp -= yylen;
  yystate = *yyssp;
  goto yyerrlab1;


/*-------------------------------------------------------------.
| yyerrlab1 -- common code for both syntax error and YYERROR.  |
`-------------------------------------------------------------*/
yyerrlab1:
  yyerrstatus = 3;	/* Each real token shifted decrements this.  */

  for (;;)
    {
      yyn = yypact[yystate];
      if (yyn != YYPACT_NINF)
	{
	  yyn += YYTERROR;
	  if (0 <= yyn && yyn <= YYLAST && yycheck[yyn] == YYTERROR)
	    {
	      yyn = yytable[yyn];
	      if (0 < yyn)
		break;
	    }
	}

      /* Pop the current state because it cannot handle the error token.  */
      if (yyssp == yyss)
	YYABORT;

      YYDSYMPRINTF ("Error: popping", yystos[*yyssp], yyvsp, yylsp);
      yydestruct (yystos[yystate], yyvsp);
      YYPOPSTACK;
      yystate = *yyssp;
      YY_STACK_PRINT (yyss, yyssp);
    }

  if (yyn == YYFINAL)
    YYACCEPT;

  YYDPRINTF ((stderr, "Shifting error token, "));

  *++yyvsp = yylval;


  yystate = yyn;
  goto yynewstate;


/*-------------------------------------.
| yyacceptlab -- YYACCEPT comes here.  |
`-------------------------------------*/
yyacceptlab:
  yyresult = 0;
  goto yyreturn;

/*-----------------------------------.
| yyabortlab -- YYABORT comes here.  |
`-----------------------------------*/
yyabortlab:
  yyresult = 1;
  goto yyreturn;

#ifndef yyoverflow
/*----------------------------------------------.
| yyoverflowlab -- parser overflow comes here.  |
`----------------------------------------------*/
yyoverflowlab:
  yyerror ("parser stack overflow");
  yyresult = 2;
  /* Fall through.  */
#endif

yyreturn:
#ifndef yyoverflow
  if (yyss != yyssa)
    YYSTACK_FREE (yyss);
#endif
  return yyresult;
}


#line 115 "arith.y"

int
arith(s)
	const char *s;
{
	long result;

	arith_buf = arith_startbuf = s;

	INTOFF;
	result = yyparse();
	arith_lex_reset();	/* reprime lex */
	INTON;

	return (result);
}


/*
 *  The exp(1) builtin.
 */
int
expcmd(argc, argv)
	int argc;
	char **argv;
{
	const char *p;
	char *concat;
	char **ap;
	long i;

	if (argc > 1) {
		p = argv[1];
		if (argc > 2) {
			/*
			 * concatenate arguments
			 */
			STARTSTACKSTR(concat);
			ap = argv + 2;
			for (;;) {
				while (*p)
					STPUTC(*p++, concat);
				if ((p = *ap++) == NULL)
					break;
				STPUTC(' ', concat);
			}
			STPUTC('\0', concat);
			p = grabstackstr(concat);
		}
	} else
		p = "";

	i = arith(p);

	out1fmt("%ld\n", i);
	return (! i);
}

/*************************/
#ifdef TEST_ARITH
#include <stdio.h>
main(argc, argv)
	char *argv[];
{
	printf("%d\n", exp(argv[1]));
}
error(s)
	char *s;
{
	fprintf(stderr, "exp: %s\n", s);
	exit(1);
}
#endif

void
yyerror(s)
	const char *s;
{

//	yyerrok;
	yyclearin;
	arith_lex_reset();	/* reprime lex */
	error("arithmetic expression: %s: \"%s\"", s, arith_startbuf);
	/* NOTREACHED */
}