function() {
    if (this.token === this.tok.T_FUNCTION) {
      this.next();
      return this.ast.useitem.TYPE_FUNCTION;
    } else if (this.token === this.tok.T_CONST) {
      this.next();
      return this.ast.useitem.TYPE_CONST;
    }
    return null;
  }
function() {
    if (this.token === this.tok.T_FUNCTION) {
      this.next();
      return this.ast.useitem.TYPE_FUNCTION;
    } else if (this.token === this.tok.T_CONST) {
      this.next();
      return this.ast.useitem.TYPE_CONST;
    }
    return null;
  }
function ( ) { if ( this . token === this . tok . T_FUNCTION ) { this . next ( ) ; return this . ast . useitem . TYPE_FUNCTION ; } else if ( this . token === this . tok . T_CONST ) { this . next ( ) ; return this . ast . useitem . TYPE_CONST ; } return null ; }
Reads the namespace type declaration
```ebnf
use_type ::= (T_FUNCTION | T_CONST)?
```
@see https://github.com/php/php-src/blob/master/Zend/zend_language_parser.y#L335
@return {String|null} Possible values : function, const
Reads the namespace type declaration ebnf use_type :: = ( T_FUNCTION | T_CONST ) ?