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RE: Why is RelationalExpr left associative?


> So the question is: why are these kinds of expressions allowed? Are 
> there any useful situations in which one can benefit?

I agree that the grammar is quirky. I think the intent here is to
allow typical recursive definitions of expressions, which typically
allow something like

  3 > 2 > 1 

to appear.

There are a number of things in XPath that are semantically
invalid, but grammatically correct. Almost all of these are
caused by some form of recursion, or inclusion of a construct
to allow it's use in different contexts through recursion.

  "foo"
  5
  "foo"[5]
  "foo"[5]
  "foo"["bar"[4]]
  5[4[3[2[1]]]]

are legal according to the grammar.

I've often thought of recasting the grammar... but it's 
probably too late now.



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