I think I recall coming across this because I was failing some tests due to whichever order the tests expected. Maybe I just noticed it from the specification though. Unfortunately it was so long ago that I don't remember.

I do not believe the problem description uniquely specifies the result of the following:

fn f x y => x * y
f 2 3 + 4

This could either return 10 or 9, depending on whether it is evaluated as (f 2 3) + 4, or f 2 (3 + 4).

Function calls should thus be added to the precedence table.

Full LR parser for learning purposes

Don't parse the output of ls: http://mywiki.wooledge.org/ParsingLs