Haskell Precedence: Lambda and operator

Question

I found precedence and associativity is a big obstacle for me to understand what the grammar is trying to express at first glance to haskell code.

For example,

Answer 1

A good rule of thumb seems to be that you can never make a custom operator that has precedence over built in syntactic constructs. For instance consider this example:

if b then f *** x else f *** y

Regardless of the associativity of ***, no one would expect it to binds as:

(if b then f *** x else f) *** y

There aren't a lot of syntactic constructs in Haskell (do and case are a little special because of layout syntax) but let can be used as another example:

(let x = y in y *** x) /= ((let x = y in y) *** x) 

Answer 2

The rule for lambdas is pretty simple: the body of the lambda extends as far to the right as possible without hitting an unbalanced parenthesis.

f (\x -> foo (bar baz) *** quux >>= quuxbar)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                       body