RegExp *ranToRE( SubStr s )
{
Range *r;
s.len -= 2; s.str += 1;
if( s.len == 0 )
return( RegExp_new_NullOp() );
r = getRange( &s );
while( s.len > 0 )
r = doUnion( r, getRange( &s ) );
return( RegExp_new_MatchOp( r ) );
}
RegExp *strToRE( SubStr s )
{
RegExp *re;
s.len -= 2; s.str += 1;
if( s.len == 0 )
return( RegExp_new_NullOp() );
re = matchChar( unescape( &s ) );
while( s.len > 0 )
re = RegExp_new_CatOp( re, matchChar( unescape( &s ) ) );
return( re );
}
RegExp *mkDiff( RegExp *e1, RegExp *e2 )
{
RegExp *m1, *m2;
Range *r;
if( !(m1 = RegExp_isA( e1, MATCHOP )) )
return( NULL );
if( !(m2 = RegExp_isA( e2, MATCHOP )) )
return( NULL );
r = doDiff( m1->u.MatchOp.match, m2->u.MatchOp.match );
return( r ? RegExp_new_MatchOp( r ) : RegExp_new_NullOp() );
}
static RegExp *
parse_factor(void)
{
RegExp *e;
char ch;
e = parse_primary();
while (curtok == CLOSE || curtok == CLOSESIZE) {
switch (curtok) {
case CLOSE:
ch = yylval.op;
while (get_next_token() == CLOSE) {
if (ch != yylval.op)
ch = '*';
}
switch (ch) {
case '*':
e = mkAlt(RegExp_new_CloseOp(e), RegExp_new_NullOp());
break;
case '+':
e = RegExp_new_CloseOp(e);
break;
case '?':
e = mkAlt(e, RegExp_new_NullOp());
break;
}
break;
case CLOSESIZE:
e = RegExp_new_CloseVOp(e, yylval.extop.minsize,
yylval.extop.maxsize);
get_next_token(); /* CLOSESIZE */
break;
default:
Scanner_fatal(in, "parse error");
break;
}
}
return e;
}
static void
yyparse(void)
{
RegExp *re, *look;
accept = 0;
spec = NULL;
get_next_token();
while (curtok != 0) {
switch (curtok) {
case ID:
get_peek_token();
if (peektok == '=') {
/* ID = expr; */
Symbol *sym = yylval.symbol;
get_next_token(); /* id */
get_next_token(); /* = */
re = parse_expr();
if (curtok != ';')
Scanner_fatal(in, "missing `;' after regexp");
get_next_token(); /* ; */
if (sym->re)
Scanner_fatal(in, "sym already defined");
sym->re = re;
break;
}
/*@fallthrough@*/
default:
/* rule: expr [/ expr] CODE */
re = parse_expr();
if (!re)
Scanner_fatal(in, "expression syntax error");
if (curtok == '/') {
get_next_token(); /* / */
look = parse_expr();
} else
look = RegExp_new_NullOp();
if (curtok != CODE)
Scanner_fatal(in, "missing code after regexp");
re = RegExp_new_RuleOp(re, look, yylval.token, accept++);
get_next_token(); /* CODE */
spec = spec ? mkAlt(spec, re) : re;
}
}
}
