def p_if_statement__if_else(self, p):
"if_statement : IF '(' expr ')' statements ELSE statements"
p[0] = ast.IfStatementAST(self, p[3], p[5], p[7])
def p_statement__if_else_if(self, p):
"if_statement : IF '(' expr ')' statements ELSE if_statement"
p[0] = ast.IfStatementAST(self, p[3], p[5],
ast.StatementListAST(self, p[7]))
def p_if_statement__if(self, p):
"if_statement : IF '(' expr ')' statements"
p[0] = ast.IfStatementAST(self, p[3], p[5], None)
