Replacement for Haml::AttributeParser available?

[raxod502]

Getting this when upgrading from 5.x to 6.x of haml:

NameError: undefined method `available?' for class `Haml::AttributeParser'

I notice that, indeed, this method has been removed. What should we use instead?

The online docs (https://haml.info/docs/yardoc/Haml/AttributeParser.html), which I understand per #1064 is not updated for 6.x, suggests that available? should "return true if AttributeParser.parse can be used". Does the absence of this method mean that in haml 6.x we can always expect AttributeParser.parse to be available?

[k0kubun]

AttributeParser is designed for an optimization and I'm not sure if it's necessarily useful as a public API, but I'm okay with resurrecting this for now. Added this back at b3cdafd.

[k0kubun]

Released as v6.0.1.