Console command line interface

Source: R/class_interface.R

These functions wrap {cli} functions and elements to build an attractive command line interface (CLI). They divide into those that change what a function does and those that only report what it did.

A call that changes control flow always fires, whatever the verbosity, because silencing it would let the code it guards run on and return a wrong answer instead of an explanation:

  • snet_abort() for an error the user has to fix.

  • snet_unavailable() for a feature that is not yet available.

  • snet_warn() for a result the user should not trust without reading, such as a value that is dropped or a name that does not match.

A call that only reports is silenced under the default verbosity:

  • snet_info() for what a function chose on the user's behalf.

  • snet_success() for the completion of a long task.

  • snet_progress_step() and the other snet_progress_*() functions for a progress bar.

  • snet_minor_info() for the bookkeeping a function did on the way, such as which column it renamed.

snet_prompt() asks the user something, so it always shows.

snet_info(..., .envir = parent.frame())

snet_minor_info(..., .envir = parent.frame())

snet_warn(..., .envir = parent.frame())

snet_abort(..., .envir = parent.frame())

snet_success(..., .envir = parent.frame())

snet_prompt(..., .envir = parent.frame())

snet_unavailable(..., .envir = parent.frame())

Arguments

...

One or more character strings. For most of these functions, if multiple strings are passed these will be pasted together.

.envir

This argument is just to inherit the parent frame in the (likely) event that the function is used within another function.

Verbosity

The snet_verbosity option takes four levels, each adding one thing to the one before it:

  • 'quiet', the default, reports nothing that is not an error, a warning, or a prompt.

  • 'normal' adds snet_info() and snet_success(), so that a user learns what a function chose on their behalf.

  • 'verbose' adds the progress bars, which reassure a user that a long task is running.

  • 'debug' adds snet_minor_info(), which reports exhaustively what a function did on the way.

Set one with, for example, options(snet_verbosity = 'verbose').