Ilya Bylich

As an option you could do something similar to what [astrolable gem does](https://github.com/yujinakayama/astrolabe/blob/master/lib/astrolabe/node.rb#L22), i.e. a custom subclass with a mutable hash property. In general I guess it's impossible to have...

> Do you have any experience with perverting it to the mutable side of the force? AFAIK there's no way in Ruby to "unfreeze" an object. > Is this completely...

Right, that's because `@children == new_children` compares items (`AST::Node`s in your case) using `==` that doesn't know about your custom attribute: ```ruby def ==(other) if equal?(other) true elsif other.respond_to? :to_ast...

Opal can handle ENV variables (by dumping all ENV variables to the file, so these values has effect only on compilation): ``` $ A=1 opal -rnodejs -e 'p ENV["A"]' "1"...

> Most of them are triggered by this edge case Hmm, this is much harder to fix because that's what is emitted by the lexer: ``` bin/ruby-parse --30 -E test.rb...

I'm not sure if I understand the point of reducing AST for *some* cases when users still need all cases. Could you explain it please? Yes, it would be easier...

> There are situations where parser right now produces different AST for the same semantics on dstrings. If we cut these cases down I'm fine. It definitely should be fixed...

I totally get it, no offense taken. I need exact code samples to talk about, and I agree that we should simplify them if possible

@wied03 Is still an issue? Got the whole gem compiled with https://github.com/opal/opal/pull/1497. Example from diff-lcs' README works as expected.

> I'll spend more time sometime this week or next week to investigate the ASAN crashes Thanks! > If you could open separate PRs with small reproduction scripts for the...