[docs] RewriteRuleSet's order dependency should be documented

[leshabirukov]

Greetings!
Using rewriter, I expected RewriteRuleSet is ,namely a set, rules not ordered and applying while any is applicable. But, as I see, order is matters. Setting commute flag didn't helped. Is this behaviour is supposed?

edit:------------------------

Yes, it is fixed as simple as

  while(
      pattern.RewriteRuleSet(
          [rule_relu, rule_leak, rule_tanh, rule_bnorm ]
      ).apply_to_model(ir_model)
  ):
      pass

[justinchuby]

The order does matter in practice because the result of one rule can affect the other. Do you have suggestions?

[leshabirukov]

Well, then it shold be 'RuleSequence'. Ok, it should be mentioned at least in docstring.

[leshabirukov]

Actually, I formulated issue badly. 'Order is matters' is expected and understood, the issue is that if second rule created possibilities for first one, algorithm don't tried to return to first rule.
And here:

onnxscript/onnxscript/rewriter/pattern.py

Line 1696 in 58aeccd

# NOTE: Rules should be prioritized in the order they are added to the RewriteRuleSet.

There, note sais 'priority', in my opinion, this means, it is intended as 'apply while any applicable', else, no mach sence use word 'priority'.
I'm not arguing, as for me, any choice is good, just need clearify this moment, and then document.

[leshabirukov]

Thanks! There is no more gap for misunderstanding.