// Factor : Primary {Primary} ;
internal RegExTree Factor() {
RegExTree tmp = Primary();
while (prStart[(int)chr] || esc)
tmp = new Binary( RegOp.concat, tmp, Primary() );
return tmp;
}
// Term : Factor {"|" Factor} ;
internal RegExTree Term() {
RegExTree tmp = Factor();
while (!esc && chr == '|') {
scan();
tmp = new Binary( RegOp.alt, tmp, Factor() );
}
return tmp;
}