Object not found when using bang-bang

[FinYang]

Help

• I understand and agree to https://books.ropensci.org/targets/help.html.

Description

Please see below the reprex. Even with tidy_eval=TRUE, bang-bang only works on global objects, not objects created in the local environment. Is there a workaround or did I miss something?

targets::tar_dir({
  targets::tar_script({
    library(targets)
    tar_option_set(packages = "rlang")
    list(
      tar_target(test,
        {
          x <- expr(a)
          expr(!!x)
        },
        tidy_eval = TRUE
      ),
    )
  })
  targets::tar_make()
})
#> 
#> ── General debugging ───────────────────────────────────────────────────────────
#> 
#> ── How to ──────────────────────────────────────────────────────────────────────
#> 
#> ── Last error message ──────────────────────────────────────────────────────────
#> 
#> ── Last error traceback ────────────────────────────────────────────────────────
#> Error:
#> ! targets::tar_make() error
#>     • tar_errored()
#>     • tar_meta(fields = any_of("error"), complete_only = TRUE)
#>     • tar_workspace()
#>     • tar_workspaces()
#>     • Debug: https://books.ropensci.org/targets/debugging.html
#>     • Help: https://books.ropensci.org/targets/help.html
#>     object 'x' not found
#>     base::tryCatch(base::withCallingHandlers({ NULL base::saveRDS(base::do.c...
#>     tryCatchList(expr, classes, parentenv, handlers)
#>     tryCatchOne(tryCatchList(expr, names[-nh], parentenv, handlers[-nh]), na...
#>     doTryCatch(return(expr), name, parentenv, handler)
#>     tryCatchList(expr, names[-nh], parentenv, handlers[-nh])
#>     tryCatchOne(expr, names, parentenv, handlers[[1L]])
#>     doTryCatch(return(expr), name, parentenv, handler)
#>     base::withCallingHandlers({ NULL base::saveRDS(base::do.call(base::do.ca...
#>     base::saveRDS(base::do.call(base::do.call, base::c(base::readRDS("/var/f...
#>     base::do.call(base::do.call, base::c(base::readRDS("/var/folders/50/2m47...
#>     (function (what, args, quote = FALSE, envir = parent.frame()) { if (!is....
#>     (function (targets_function, targets_arguments, options, envir = NULL, s...
#>     tryCatch(out <- withCallingHandlers(targets::tar_callr_inner_try(targets...
#>     tryCatchList(expr, classes, parentenv, handlers)
#>     tryCatchOne(expr, names, parentenv, handlers[[1L]])
#>     doTryCatch(return(expr), name, parentenv, handler)
#>     withCallingHandlers(targets::tar_callr_inner_try(targets_function = targ...
#>     targets::tar_callr_inner_try(targets_function = targets_function, target...
#>     eval(parse(file = script, keep.source = TRUE), envir = envir)
#>     eval(parse(file = script, keep.source = TRUE), envir = envir)
#>     tar_target(test, { x <- expr(a) expr(!!x) }, tidy_eval = TRUE)
#>     tar_tidy_eval(command, envir, tidy_eval)
#>     rlang::quo_squash(eval(expr, envir = envir))
#>     is_quosure(quo)
#>     eval(expr, envir = envir)
#>     eval(expr, envir = envir)
#>     rlang::expr({ x <- expr(a) expr(!!x) })
#>     enexpr(expr)

^{Created on 2024-12-09 with reprex v2.1.1}

[wlandau]

This is by design. tar_target(tidy_eval = TRUE) is a way to inject global variables into the target commands in _targets.R.

[FinYang]

Thanks for your reply. Does that mean I couldn't/shouldn't use non-standard evaluation inside the target commands unless it's about global variables? It also doesn't work when tidy_eval = FALSE.

[wlandau]

Use tidy_eval = TRUE to insert global variables into commands before the pipeline runs. Use tidy_eval = FALSE if you want the !! to run when the target runs.

[FinYang]

Thank you very much! I assumed the default is tidy_eval = FALSE and just realised I must set it to FALSE for it to work inside the target.