function() {
    switch (this.token) {
      case this.tok.T_FUNCTION:
        return this.read_function(false, false);
      // optional flags
      case this.tok.T_ABSTRACT:
      case this.tok.T_FINAL:
      case this.tok.T_CLASS:
        return this.read_class();
      case this.tok.T_INTERFACE:
        return this.read_interface();
      case this.tok.T_TRAIT:
        return this.read_trait();
      case this.tok.T_USE:
        return this.read_use_statement();
      case this.tok.T_CONST: {
        const result = this.node("constantstatement");
        const items = this.next().read_const_list();
        this.expectEndOfStatement();
        return result(null, items);
      }
      case this.tok.T_NAMESPACE:
        return this.read_namespace();
      case this.tok.T_HALT_COMPILER: {
        const result = this.node("halt");
        if (this.next().expect("(")) this.next();
        if (this.expect(")")) this.next();
        this.expect(";");
        this.lexer.done = true;
        return result(this.lexer._input.substring(this.lexer.offset));
      }
      default:
        return this.read_statement();
    }
  }
function() {
    switch (this.token) {
      case this.tok.T_FUNCTION:
        return this.read_function(false, false);
      
      case this.tok.T_ABSTRACT:
      case this.tok.T_FINAL:
      case this.tok.T_CLASS:
        return this.read_class();
      case this.tok.T_INTERFACE:
        return this.read_interface();
      case this.tok.T_TRAIT:
        return this.read_trait();
      case this.tok.T_USE:
        return this.read_use_statement();
      case this.tok.T_CONST: {
        const result = this.node("constantstatement");
        const items = this.next().read_const_list();
        this.expectEndOfStatement();
        return result(null, items);
      }
      case this.tok.T_NAMESPACE:
        return this.read_namespace();
      case this.tok.T_HALT_COMPILER: {
        const result = this.node("halt");
        if (this.next().expect("(")) this.next();
        if (this.expect(")")) this.next();
        this.expect(";");
        this.lexer.done = true;
        return result(this.lexer._input.substring(this.lexer.offset));
      }
      default:
        return this.read_statement();
    }
  }
function ( ) { switch ( this . token ) { case this . tok . T_FUNCTION : return this . read_function ( false , false ) ; // optional flags case this . tok . T_ABSTRACT : case this . tok . T_FINAL : case this . tok . T_CLASS : return this . read_class ( ) ; case this . tok . T_INTERFACE : return this . read_interface ( ) ; case this . tok . T_TRAIT : return this . read_trait ( ) ; case this . tok . T_USE : return this . read_use_statement ( ) ; case this . tok . T_CONST : { const result = this . node ( "constantstatement" ) ; const items = this . next ( ) . read_const_list ( ) ; this . expectEndOfStatement ( ) ; return result ( null , items ) ; } case this . tok . T_NAMESPACE : return this . read_namespace ( ) ; case this . tok . T_HALT_COMPILER : { const result = this . node ( "halt" ) ; if ( this . next ( ) . expect ( "(" ) ) this . next ( ) ; if ( this . expect ( ")" ) ) this . next ( ) ; this . expect ( ";" ) ; this . lexer . done = true ; return result ( this . lexer . _input . substring ( this . lexer . offset ) ) ; } default : return this . read_statement ( ) ; } }
reading a top statement
```ebnf
top_statement ::=
namespace | function | class
| interface | trait
| use_statements | const_list
| statement
```
reading a top statement ebnf top_statement :: = namespace | function | class | interface | trait | use_statements | const_list | statement