#NEWLINE# def _tgrep_parens_action( _s , _l , tokens ) : #NEWLINE# #INDENT# '\n    Builds a lambda function representing a predicate on a tree node\n    from a parenthetical notation.\n    ' #NEWLINE# assert ( len ( _s ) == 3 ) #NEWLINE# assert ( tokens [ 0 ] == '(' ) #NEWLINE# assert ( tokens [ 2 ] == ')' ) #NEWLINE# return tokens [ 1 ]