This tiny library can be used to show some kind of progress indicator while executing some long running task. Especially, while writing small kotlin scripts it is tedious to reinvent a minimal progress indicator. Therefore this library provide an easy yet flexible interface for progress control. Further, in the case of simply printing to a console, a couple of pre-formatted values are at hand to compose a progress statement quickly: Like a progress bar, the elapsed and remaining time etc. (see complete set of features below).

This library was inspired by the R package progress.

import com.zypus.progress.Progress

fun main() {
    // Create a control with 100 ticks.
    val control = Progress.control(100L) {
        // On each update print (reprint) an informative statement about the progress.
        print("\r [$bar] $percent eta: $eta")
    }
    
    // Do the work.
    for (i in 1..100) {
        // Some expensive task.
        control.tick()
    }
}

The output of this small program will look something like this:

[======--------------]  30.0% eta: 10s

This is the complete set of pre-formatted features available in the progress update. (Of course the raw values are also available.)

For convenience this library adds extension functions for Collections, Iterables, Sequences and for reading files to minimise the boilerplate even further:

import com.zypus.progress.forEachBlockWithProgress

val file: java.io.File = // some File

// Read and process a potentially huge file.
file.forEachBlockWithProgress { buffer, bytesRead ->
	// process the file
}

And get output like this for free:

(/)   6.0s [===========---------]  55.0% (  2.27MB/4.12MB @ 378.2kB/s) eta:   5.0s

To get started simply add it as a dependency via jcenter:

compile "com.zypus:progress:1.0.0"

<dependency>
   <groupId>com.zypus</groupId>
   <artifactId>progress</artifactId>
   <version>1.0.0</version>
</dependency>

Apache License 2.0