original_string: public function addExpression($name, $expression = null)
      {
          /** @type Field_Expression $f */
          $f = $this->add('Field_Expression', $name);
  
          return $f->set($expression);
      }
code: public function addExpression($name, $expression = null)
      {
          /** @type Field_Expression $f */
          $f = $this->add('Field_Expression', $name);
  
          return $f->set($expression);
      }
code_tokens: public function addExpression ( $ name , $ expression = null ) { /** @type Field_Expression $f */ $ f = $ this -> add ( 'Field_Expression' , $ name ) ; return $ f -> set ( $ expression ) ; }
docstring: Adds and returns SQL-calculated expression as a read-only field.
  
  See Field_Expression class.
  
  @param string $name
  @param mixed $expression
  
  @return DB_dsql
docstring_tokens: Adds and returns SQL - calculated expression as a read - only field .