zephir.bnf

                       <zephir> ::= <top statement list>

           <top statement list> ::= <top statement list> <top statement>
           <top statement list> ::= <top statement>

                <top statement> ::= <namespace definition>
                <top statement> ::= <use aliases>
                <top statement> ::= <function definition>
                <top statement> ::= <class definition>
                <top statement> ::= <interface definition>
                <top statement> ::= <comment>
                <top statement> ::= <cblock>

         <namespace definition> ::= namespace <identifier> ;
         <namespace definition> ::= use <use aliases-list> ;

             <use aliases list> ::= <use aliases list> , <use aliases>
             <use aliases list> ::= <use aliases>

                  <use aliases> ::= <identifier>
                  <use aliases> ::= <identifier> as <identifier>

          <function definition> ::= <function label> <identifier> ( ) -> method-return-type { }
          <function definition> ::= <function label> <identifier> ( ) -> method-return-type ;
          <function definition> ::= <function label> <identifier> ( parameter-list ) -> method-return-type { }
          <function definition> ::= <function label> <identifier> ( parameter-list ) -> method-return-type ;
          <function definition> ::= <function label> <identifier> ( ) -> method-return-type { statement-list }
          <function definition> ::= <function label> <identifier> ( parameter-list ) -> method-return-type { statement-list }
          <function definition> ::= <function label> <identifier> ( ) { }
          <function definition> ::= <function label> <identifier> ( ) ;
          <function definition> ::= <function label> <identifier> ( parameter-list ) { }
          <function definition> ::= <function label> <identifier> ( parameter-list ) ;
          <function definition> ::= <function label> <identifier> ( ) { statement-list }
          <function definition> ::= <function label> <identifier> ( parameter-list ) { statement-list }

               <function label> ::= function | fn

         <interface definition> ::= interface <identifier> <interface body definition>
         <interface definition> ::= interface <identifier> extends <implements list> <interface body definition>

             <class definition> ::= <class scope> class <identifier> <class body definition>
             <class definition> ::= <class scope> class <identifier> extends <identifier> <class body definition>
             <class definition> ::= <class scope> class <identifier> implements <implements list> <class body definition>
             <class definition> ::= <class scope> class <identifier> extends <identifier> implements <implements list> <class body definition>

                  <class scope> ::= abstract | final | internal | <empty>

                        <empty> ::=

        <class body definition> ::= { }
        <class body definition> ::= { <class body> }

              <implements list> ::= <implements list> , <implements>
              <implements list> ::= <implements>

                   <implements> ::= <identifier>

    <interface body definition> ::= { }
    <interface body definition> ::= { <interface body> }

                   <class body> ::= <class properties definition>
                   <class body> ::= <class consts definition>
                   <class body> ::= <class methods definition>
                   <class body> ::= <class methods definition>
                   <class body> ::= <class properties definition> <class consts definition>
                   <class body> ::= <class consts definition> <class properties definition>
                   <class body> ::= <class consts definition> <class methods definition>
                   <class body> ::= <class properties definition> <class consts definition> <class methods definition>
                   <class body> ::= <class consts definition> <class properties definition> <class methods definition>

               <interface body> ::= <class consts definition>
               <interface body> ::= <interface methods definition>
               <interface body> ::= <class consts definition> <interface methods definition>

  <class properties definition> ::= <class properties definition> <class property definition>
  <class properties definition> ::= <class property definition>

    <class property definition> ::= <property comment> <visibility list> <identifier> ;
    <class property definition> ::= <property comment> <visibility list> <identifier> = <literal expression> ;
    <class property definition> ::= <property comment> <visibility list> <identifier> <class property shortcuts> ;
    <class property definition> ::= <property comment> <visibility list> <identifier> = <literal expr> <class property shortcuts> ;

             <property comment> ::= <comment> | <empty>

     <class property shortcuts> ::= { }
     <class property shortcuts> ::= { <class property shortcuts list> }

<class property shortcuts list> ::= <class property shortcuts list> , <class property shortcut>
<class property shortcuts list> ::= <class property shortcut>

      <class property shortcut> ::= <property comment> <identifier>

; 409 constants definition