Report unknown chord flavours about chordinaryworld HOT 1 CLOSED

Logging has been introduced.

This approach was used, to not mix cross-cutting concerns with business logic. Generally, it is Decorator pattern but thanks to functional paradigm its ends up with only appending a function in pipeline.

Was:

    song
    |> Validator.ValidateSong
    |> bind ChordsProvider.GetChords
    |> bind Engine.GetNumberOfHarmonies

Now:

    song
    |> Validator.ValidateSong
    |> bind ChordsProvider.GetChords
    |> bind Engine.GetNumberOfHarmonies
    |> Logger.Log song

It was hard to choose a framework for Logger. First attempt was to introduce Logary which is written in F# for F#. However, there were a couple of obstacles.

1. For simplicity I wanted to start with logging to file which seems to be somewhat hard to set with Logary
2. I did not want to think how to set logger globally via code

The second relates to many other logging platforms. The one that provides a way to bypass these considerations is NLog. It allows to set the logger via configuration file which is just what is needed currently.

So, for now logging is trivial, it only logs unknown flavours together with the song where they are found. Logging runs locally, saves info to nearly hardcoded paths, not at hosting service. It all should be improved.

from chordinaryworld.