PWB1/sys/source/s2/yacc.d/yaccrpar

yydebu = yyargu;
yystat = 0;
yychar = -1;
yynerr = 0;
yyerrf = 0;
yypv = 0;

999 if( yydebu != 0 ) {
	write( 6, 911 ) yystat, yyval, yychar, yypv
911	format("state ", i5, "  value ", i6, "  char ", i6, "  level ", i3 )
	}

yypv = yypv + 1
yys( yypv ) = yystat
yyvalv( yypv ) = yyval

920

yyn = yypact( yystat+1 )

if( yyn <= (-1000) ) goto 950

if( yychar<0 ) yychar = yylex(yylval);

if( yydebu > 1 ){
	write( 6, 921 ) yyn, yychar
921	format( "n = ", i6, "  char = ", i5 )
	}
yyn = yyn + yychar;
if( yyn < 0 || yyn >= YYLAST ) goto 950
yyn = yyact( yyn+1 )
if( yychk( yyn+1 ) == yychar ){
	yychar = -1
	yyval = yylval
	yystat = yyn
	if( yyerrf > 0 ) yyerrf = yyerrf - 1
	goto 999
	}

950

	if( yydebu > 1 ){
		write( 6, 951 ) yyn
951		format( "default is ", i5 )
		}

	yyn = yydef( yystat+1 )

	if( yyn == (-2) ) {
		if( yychar < 0 ) yychar = yylex(yylval);
		yyn = yyexcp( yystat, yychar );
		}

	if( yyn == (-1 ) ) {
		yypars = 0;
		return;
		}

	if( yyn == 0 ){

		if( yyerrf == 3 ){

			if( yydebu != 0 ){
				write( 6, 961 ) yychar
				961 format( "error recovery discards char ", i5 )
				}

			if( yychar == (-1) ){
				yypars = 1
				return
				}

			yychar = -1
			goto 920
			}

		if( yyerrf == 0 ){#  new error
			write( 6, 971 ) 
			971 format( "syntax error" )
			975 continue   # for simulated arror activity
			yynerr = yynerr + 1;
			}

		yyerrf = 3

		# find a state where error is a legal shift

		while( yypv >= 1 ){
			yyn = yys( yypv )
			yyn = yypact(  yyn+1 ) + YYERRCODE
			if( yyn >= 0 && yyn < YYLAST ){
				yyn = yyact( yyn+1 )
				if( yychk( yyn+1 ) == YYERRCODE ){
					yystat = yyn
					goto 999
					}
				}

			if( yydebu != 0 ){
				write ( 6, 972 ) yys(yypv ), yys( yypv-1 )
				972 format( "error recovery pops ", i4, " uncovers ", i4 )
				}

			yypv = yypv - 1
			}

		yypars = 1
		return

		}

	if( yydebu != 0 ){
		write ( 6, 981 ) yyn
981		format( "reduce ", i5 )
		}

	yypvt = yypv
	yym = yyn
	yypv = yypv - yyr2( yyn+1 )
	yyval = yyvalv( yypv+1 )
	if( yydebu > 2 ){
		write( 6, 982 ) yys(yypv), yypv, yyval
982		format( "reduce uncovers ", i4, " level ", i3, " val ", i6 )
		}
	yyn = yyr1( yyn+1 )
	yyj = yypgo( yyn+1 ) + yys( yypv ) +2
	if( yyj > YYLAST ) goto 990
	yystat = yyact( yyj )
	if( yychk( yystat+1 ) != ( -yyn ) ){
		990 yyn = yypgo( yyn+1 )
		yystat = yyact( yyn+1 )
		}
	goto 1000
	$A
	end