R 无法尝试捕获多个错误

Question

我想在超时错误中捕获无效输入错误。我写的脚本如下。但是，在这种情况下超时不起作用，程序永远运行。任何人都可以请检查并让我知道如何解决它吗？谢谢。

for (lb in 1:100) {
  rs <- tryCatch(
          expr = {
            cat("helloworld", "\n");
            withTimeout({
              rs_son = tryCatch(
                expr = {
                  flag = FALSE
                  cat("start solnl", "\n");
                  ret = solnl(X, objfun = obj, confun = con, lb=lb, ub=ub);
                  cat("finish solnl", "\n");
                },
                error = function(e) {flag <- TRUE}
              )
              if(flag) {next}
            },
            timeout = 10)
          },
          TimeoutException = function(ex) {
            cat("Timeout. Skipping.\n")
          }
        )
}

更清楚地说，这就是我想要实现的目标。无论这是对 solnl 函数的无效输入错误还是超时错误，for 循环都应该继续。

Answer 1

这里有多个问题。第一，没有循环调用next，第二，flag只定义在错误处理函数内部，不在tryCatch()之外，第三，外部tryCatch()在这里没有影响。

我添加了一些进一步的 cat 消息，希望能对正在发生的事情有所了解

编辑：用正确的 for 循环更新答案

set.seed(0)
rs <- character()
for (lb in 1:10) {
  
  rs[lb] <- R.utils::withTimeout({
    rs_son = tryCatch(
      expr = {
        flag <- FALSE # has no impact
        Sys.sleep(sample(0:2, size = 1))
        cat("start solnl", "\n")
        ret = solnl(X, objfun = obj, confun = con, lb=lb, ub=ub)
        cat("finish solnl", "\n")
      },
      error = function(e) {
        cat(as.character(e))
        flag <- TRUE # equals return(TRUE)
      }
    )
    if(rs_son) {
      return("NEXT OUT")
    }
    return("OUT")
  },
  timeout = 1)
  
  
}
#> Error in Sys.sleep(sample(0:2, size = 1)): reached elapsed time limit
#> start solnl 
#> Error in solnl(X, objfun = obj, confun = con, lb = lb, ub = ub): could not find function "solnl"
#> Error in Sys.sleep(sample(0:2, size = 1)): reached elapsed time limit
#> start solnl 
#> Error in solnl(X, objfun = obj, confun = con, lb = lb, ub = ub): could not find function "solnl"
#> Error in Sys.sleep(sample(0:2, size = 1)): reached elapsed time limit
#> start solnl 
#> Error in solnl(X, objfun = obj, confun = con, lb = lb, ub = ub): could not find function "solnl"
#> Error in Sys.sleep(sample(0:2, size = 1)): reached elapsed time limit
#> Error in Sys.sleep(sample(0:2, size = 1)): reached elapsed time limit
#> start solnl 
#> Error in solnl(X, objfun = obj, confun = con, lb = lb, ub = ub): could not find function "solnl"
#> start solnl 
#> Error in solnl(X, objfun = obj, confun = con, lb = lb, ub = ub): could not find function "solnl"

rs
#>  [1] "NEXT OUT" "NEXT OUT" "NEXT OUT" "NEXT OUT" "NEXT OUT" "NEXT OUT"
#>  [7] "NEXT OUT" "NEXT OUT" "NEXT OUT" "NEXT OUT"