def p_case_clause(self, p):
        """case_clause : CASE expr COLON source_elements"""
        p[0] = ast.Case(expr=p[2], elements=p[4])
def p_case_clause ( self , p ) : p [ 0 ] = ast . Case ( expr = p [ 2 ] , elements = p [ 4 ] )
case_clause : CASE expr COLON source_elements