haskell

Haskell tutorial I like best: http://learnyouahaskell.com
"A gentle introduction to Haskell" is also probably good,
intended as a supplement to the original technical report.

Hmm, this appeared too, it looks quite good:
  https://en.wikibooks.org/wiki/Haskell
and it references a meta-tutorial for finding a good tutorial:
  https://wiki.haskell.org/Meta-tutorial

Other good references:
  Good intro/overview of syntax:
  https://www.fpcomplete.com/blog/2012/09/ten-things-you-should-know-about-haskell-syntax

  http://www.haskellforall.com/2015/09/how-to-make-your-haskell-code-more.html


Q: What are the operator precendences?
   All I know is they go from 0 (lowest) to 9 (highest),
    - $ (function application) has precedence 0 (lowest),
    - . (function composition) has precendence 9 (highest)
    - whitespace (function application) has precedence even higher than that.

Quiz: how many different ways can you express f(g(x)), using
      different combinations of parentheses, . (function composition), $ (function application)
Answer:
   f(g(x)) can be expressed as:

     f (g x)
     f (g $ x)
     f $ (g x)
     f $ g x
     f $ (g $ x)
     f $ g $ x

     (f $) (g x)
     f $ ((g $) x)
     (f $) ((g $) x)

     f (($ x) g)
     ($ (g $ x)) f
     ($ (($ x) g)) f

     (f $) (($ x) g)
     ($ ((g $) x)) f

     -- maybe should disallow the prefix forms, there's too much blowup:
     f (($) g x)
     f ((($) g) x)

     ($) f (g x)
     (($) f) (g x)
     ($) f (g $ x)
     (($) f) (g $ x)
     ($) f ((g $) x)
     (($) f) ((g $) x)

     f $ (($) g x)
     (f $) (($) g x)
     f $ ((($) g) x)
     (f $) ((($) g) x)

     ($) f (($) g x)
     ($) f ((($) g) x)
     (($) f) (($) g x)
     (($) f) ((($) g) x)
     -- I probably missed some.  Note that ($) f is just f, so you can
        pretty much stick a ($) in front of any function even itself,
        so it's not that interesting.

     -- but even if we disallow the prefix form, these forms
        can blow up too:
        f$, g$, $(g x), $x

     (f . g) x
     f . g $ x
     ((f .) g) x
     ((f .) g) $ x
     ((. g) f) x
     ((. g) f) $ x

   Try them out:
     f = (*3)
     g = (+100)
     x = 1