anchor.diff:  /*
   PHP grammar.
   The MIT License (MIT).
  -Copyright (c) 2015-2017, Ivan Kochurkin (kvanttt@gmail.com), Positive Technologies.
  +Copyright (c) 2015-2019, Ivan Kochurkin (kvanttt@gmail.com), Positive Technologies.
   Copyright (c) 2019, Student Main for php7 support.
   
   Permission is hereby granted, free of charge, to any person obtaining a copy
  
positive.code: 
      | Throw expression                                          #SpecialWordExpression
  
      | assignable assignmentOperator attributes? expression     #AssignmentExpression
      | assignable Eq attributes? '&' (chain | newExpr)          #AssignmentExpression
  
      | expression op=LogicalAnd expression                       #LogicalExpression
      | expression op=LogicalXor expression                       #LogicalExpression
  
negative.code:     | breakStatement
      | continueStatement
      | returnStatement
      | yieldExpression SemiColon
      | globalStatement
      | staticVariableStatement
      | echoStatement
  