Display a progress bar on one line.

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• Support for real and dumb terminal windows
  • on the terminal, it correctly updates the progress percent and the number of items. On a dumb terminal like Emacs Slime, it can't erase the previous step to update the numbers, so it simply prints one progress indicator after the other, still on one line.

Status: usable for simple cases, adds too much overhead with large datasets, work in progress, the API might change.

This library is on Ultralisp,

and on Quicklisp since the 2024-10 release.

Instantiate with (progressbar data) and call (step!) at each iteration.

(loop for elt in (progressbar (list12345)) do (do-something-with elt) (sleep0.1) (step!))

data is a list of data, or an integer specifying the number of iterations.

Use the bar character you want with :bar ">" (a character or a string of one element):

(loop for line in (progressbar (list12345) :bar">") do (sleep0.3) (step!)) [0/5]>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>[100%]

Use (progressbar data :rainbow t) for some colors:

but… that works only on a dumb terminal, too bad (we don't see the progress on a real terminal).

Run the demo:

sbcl --load demo.lisp # aka make demo 

Manual progress:

CL-USER> (progressbar (list 1 2 3 4 5)) (1 2 3 4 5) #<PROGRESS BAR, length 5, step 16> CL-USER> (step!) >>>>>>>>>>>>>>>> [20] CL-USER> (step!) >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> [40] […] CL-USER> (step!) >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>[100] 

step! takes an optional progressbar object as argument.

We'd like to remove the need of calling (step!) eventually.

The guist of a progress bar is to print a string, then erase it to print a longer one by printing a backspace character (write-char #\return).

https://github.com/sirherrbatka/cl-progress-bar (oops, it's probably OK for my use case and more complete)

https://40ants.com/lisp-project-of-the-day/2020/04/0034-cl-progress-bar.html

Licence: MIT