| -- i mean, this is basically just a high school formula sheet | |
| -- that happens to also be valid haskell | |
| -- (we're differentiating against "Symbol") | |
| diff (Symbol) = Val 1 | |
| diff (Neg x) = Neg (diff x) | |
| diff (Add x y) = Add (diff x) (diff y) | |
| diff (Mul x y) = Add (Mul (diff x) y ) (Mul x (diff y)) | |
| diff (Sub x y) = diff (Add x (Neg y)) | |
| diff (Pow x (Val n)) = Mul (Val n) (Pow x (Val (n - 1) ) ) |
###Andrew Alexander
A loose transcription of an impromptu five-minute presentation at the Recurse Center, 5 May 2016
##Pattern-matching
(I don't think "pattern matching" is a great name, but this is what everyone calls it.) Anyway, in normal programming, you define a function exactly ONCE, and if you need it to behave differently depending on what its input is, you have to write if-then branches or switch or case statements, and things can get very ugly very fast.
A list of useful commands for the FFmpeg command line tool.
Download FFmpeg: https://www.ffmpeg.org/download.html
Full documentation: https://www.ffmpeg.org/ffmpeg.html