如何在R的CLI错误消息中精准展示...参数的传入内容

解决方案 #

1. 简洁显示筛选条件 #

使用rlang::exprs()捕获传入...的表达式，再通过purrr::map_chr()配合rlang::expr_text()转换为干净的文本格式，最后用逗号拼接即可去除冗余符号：

library(dplyr)
library(cli)
library(rlang)
library(purrr)

filter_to_one <- function(df, ...) {
  filter_exprs <- exprs(...)
  filtered <- df |> filter(!!!filter_exprs)
  n <- nrow(filtered)
  if (n != 1) {
    criteria <- map_chr(filter_exprs, expr_text) |> paste(collapse = ", ")
    cli_abort(
      c("Did not find one unique match, found {n}.",
        "i" = "filter criteria: {criteria}"
      )
    )
  } else {
    filtered
  }
}

mtcars |> filter_to_one(cyl == 6 & gear == 4, mpg > 20)
#> Error in `filter_to_one()`:
#> ! Did not find one unique match, found 2.
#> ℹ filter criteria: cyl == 6 & gear == 4, mpg > 20

2. 重现完整函数调用 #

通过rlang::call2()构造完整的函数调用表达式，再用rlang::expr_text()转换为可读文本，无需字符串拼接即可精准还原调用：

基础版（含数据框参数）

library(dplyr)
library(cli)
library(rlang)

filter_to_one <- function(df, ...) {
  filtered <- df |> filter(...)
  n <- nrow(filtered)
  if (n != 1) {
    full_call <- call2("filter_to_one", enexpr(df), ...)
    call_text <- expr_text(full_call)
    cli_abort(
      c("Did not find one unique match, found {n}.",
        "i" = "call: {call_text}"
      )
    )
  } else {
    filtered
  }
}

mtcars |> filter_to_one(cyl == 6 & gear == 4, mpg > 20)
#> Error in `filter_to_one()`:
#> ! Did not find one unique match, found 2.
#> ℹ call: filter_to_one(mtcars, cyl == 6 & gear == 4, mpg > 20)

管道调用还原版

如果想贴近原代码的管道写法，用rlang::expr()构造管道表达式：

library(dplyr)
library(cli)
library(rlang)

filter_to_one <- function(df, ...) {
  filtered <- df |> filter(...)
  n <- nrow(filtered)
  if (n != 1) {
    full_call <- expr(!!enexpr(df) |> filter_to_one(!!!exprs(...)))
    call_text <- expr_text(full_call)
    cli_abort(
      c("Did not find one unique match, found {n}.",
        "i" = "call: {call_text}"
      )
    )
  } else {
    filtered
  }
}

mtcars |> filter_to_one(cyl == 6 & gear == 4, mpg > 20)
#> Error in `filter_to_one()`:
#> ! Did not find one unique match, found 2.
#> ℹ call: mtcars |> filter_to_one(cyl == 6 & gear == 4, mpg > 20)

内容的提问来源于stack exchange，提问作者mac