Allow searching for arguments by name (regardless of value)

[rossellhayes]

If the match argument of find_arguments() is a character vector, find arguments by name regardless of value.

library(gradecode)
.user_code <- "mean(rnorm(10, mean = 1, sd = 0.1), na.rm = TRUE)"

find_arguments(.user_code, match = "na.rm")
#> 
#> ── gradecode found ─────────────────────────────────────────────────────────────
#> mean(rnorm(10, mean = 1, sd = 0.1), na.rm = TRUE)
#> 
#> ── Request ──
#> argument na.rm
#> Found 1 result.
#> 
#> ── Result 1 ──
#> mean(rnorm(10, mean = 1, sd = 0.1), na.rm = TRUE)
#>                                     ‾‾‾‾‾‾‾‾‾‾‾‾

If match is a character vector of length > 1, find any of those arguments.

find_arguments(.user_code, match = c("mean", "sd"))
#> 
#> ── gradecode found ─────────────────────────────────────────────────────────────
#> mean(rnorm(10, mean = 1, sd = 0.1), na.rm = TRUE)
#> 
#> ── Request ──
#> argument mean > NA sd
#> Found 2 results.
#> 
#> ── Result 1 ──
#> mean(rnorm(10, mean = 1, sd = 0.1), na.rm = TRUE)
#>                ‾‾‾‾‾‾‾‾
#> 
#> ── Result 2 ──
#> mean(rnorm(10, mean = 1, sd = 0.1), na.rm = TRUE)
#>                          ‾‾‾‾‾‾‾‾

^{Created on 2022-10-05 with reprex v2.0.2}

Closes #45.

[gadenbuie]

Very nice!

[rossellhayes]

@gadenbuie One final detail worth reviewing before I merge. 569f506 adds support for finding unnamed arguments with an empty string, like this:

library(gradecode)
find_arguments("mean(1:10, na.rm = TRUE)", match = "")
#> 
#> ── gradecode found ─────────────────────────────────────────────────────────────
#> mean(1:10, na.rm = TRUE)
#> 
#> ── Request ──
#> argument ""
#> Found 1 result.
#> 
#> ── Result 1 ──
#> mean(1:10, na.rm = TRUE)
#>      ‾‾‾‾

^{Created on 2022-10-06 with reprex v2.0.2}

Is that a good interface?

(function("" = value) fails, so there's no risk of confusing unnamed arguments with arguments that are literally named "").