pars repres or separ oper contain initi handl occur param classifi classifi classifi oper belong param oper oper oper edit happen param text pars pars except invalid input pars oper fig object classifi object oper text pars except classifi oper pars except pex start end notat util uml index check semicolon text start project current project project manag manag current project end text remov op current project trash oper text substr start end trim length non whitechar text remov op current project trash oper pars oper oper model facad featur classifi index oper check oper separ start end end notat util uml index check semicolon text start end start end text length text substr start end trim length ye object type current project type object op model core factori build oper classifi type op pars oper op op set owner scope op owner scope need oper model core helper add featur classifi op model core helper add featur classifi op pars except ex pex pex ex start end end notat util uml index check semicolon text start pex pex 