public function onConstantExpression(IType $type, $value)
    {
        if (is_bool($value)) {
            return var_export($value, true);
        } elseif (null === $value) {
            return var_export(null, true);
        }
        return $value;
    }
public function onConstantExpression(IType $type, $value)
    {
        if (is_bool($value)) {
            return var_export($value, true);
        } elseif (null === $value) {
            return var_export(null, true);
        }
        return $value;
    }
public function onConstantExpression ( IType $ type , $ value ) { if ( is_bool ( $ value ) ) { return var_export ( $ value , true ) ; } elseif ( null === $ value ) { return var_export ( null , true ) ; } return $ value ; }
Call-back for constant expression.

@param IType $type  The type of constant
@param mixed $value The value of the constant

@return string
Call - back for constant expression .