package Ġpw . bin om . material . compiler Ċ Ċ import Ġpw . bin om . material . Source Point Ċ import Ġpw . bin om . material . lex . Operation Expression Ċ Ċ class ĠAssign Statement Desc ( val Ġfield : ĠField Access Expression Desc , Ġval Ġexp : ĠExpression Desc , Ġval Ġoperator : ĠOperation Expression . Operator ?, Ġsource : ĠSource Point ) Ġ: ĠStatement Desc ( source ) Ġ{ ĊĠĠĠ Ġoverride Ġval Ġchild s : ĠSequence < Source Element > ĊĠĠĠĠĠĠĠ Ġget () Ġ= Ġsequence Of ( this . field , Ġexp ). filter NotNull () Ċ }