Re: [Haskell-cafe] Language complexity & beginners

9 Feb 2016

      Bryan Richter  writes:
...
On Tue, Feb 09, 2016 at 02:27:44PM +0300, Kosyrev Serge wrote:
...
Michael Orlitzky  writes:
...
Most uses of "$" are for stupid
things like "sin $ 1 + 2" where parentheses would be much more clear.
"$" simplifies visual perception through two factors:
1. we are relieved from counting parentheses
  2. it serves as a cue to treat the entire remaining part until ")" as
     part of the same expression
Case in point (only slightly contrived) -- which one is easier to
visually parse to you:
foo (thInt $ fromIntegral $ c2hsValueInt cexp) (thInt $ fromIntegral $ c2hsValueInt cexp)
foo (thInt (fromIntegral (c2hsValueInt cexp))) (thInt (fromIntegral (c2hsValueInt cexp)))
My readability problem with this statement is line length. How about:
foo (thInt (fromIntegral (c2hsValueInt cexp)))
        (thInt (fromIntegral (c2hsValueInt cexp)))
I clearly made a mistake of duplicating a real expression.. should have
picked two different expressions for an example.

The point I have tried to convey was that:

  - the ))) ( patterns are hard to parse visually
  - the $ helps to alleviate that

..which is fairly orthogonal to common subexpression elimination or formatting.

$ allows one to write more complex expressions -- precisely without
resorting to diluting code with formatting.

-- 
с уважениeм / respectfully,
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