allow expression functions to be used in multiple instances of the same subclass with the correct context
allow expression functions to be used in multiple instances of the same subclass with the correct context

cgvarela/ractive,cgvarela/ractive,magicdawn/ractive,marcalexiei/ractive,Rich-Harris/ractive,ISNIT0/ractive,cgvarela/ractive,aliprogrammer69/ractive,squaredup/ractive,magicdawn/ractive,ndimas/ractive,squaredup/ractive,ndimas/ractive,thomsbg/ractive,heavyk/ractive,JonDum/ractive,ractivejs/ractive,aliprogrammer69/ractive,npmcomponent/RactiveJS-Ractive,JonDum/ractive,heavyk/ractive,ISNIT0/ractive,npmcomponent/RactiveJS-Ractive,thomsbg/ractive,Rich-Harris/ractive,thomsbg/ractive,ISNIT0/ractive,JonDum/ractive,dyx/ractive,pingjiang/ractive,aliprogrammer69/ractive,dyx/ractive,p0lax/ractive,marcalexiei/ractive,Rich-Harris/ractive,marcalexiei/ractive,pingjiang/ractive,p0lax/ractive,pingjiang/ractive,ractivejs/ractive,ractivejs/ractive,ndimas/ractive,magicdawn/ractive,heavyk/ractive,squaredup/ractive,dyx/ractive