Issue #21795 has been updated by Eregon (Benoit Daloze). I have now implemented both `#syntax_tree` and `#source_range` in TruffleRuby. It went mostly fine, and I added a number of specs for `#syntax_tree`. I noticed one case of implementation complexity and inconsistency caused by returning `CallNode` instead of `BlockNode` for `{Proc,Method,UnboundMethod}#syntax_tree`. #21998 discussed this at length and notably https://bugs.ruby-lang.org/issues/21998#note-24 summarizes the reason to prefer `BlockNode`. So I think we should consolidate to `BlockNode` for `#syntax_tree` and `#source_range`. Is there a specific use case where getting the `CallNode` is necessary and the `BlockNode` is not enough? One example for thought: ```ruby def bar(*args, &block) p args.sum block end body = bar(1, 2, 3) { 42 } define_method(:foo, &body) p method(:foo).syntax_tree ``` The `CallNode` is `bar(1, 2, 3) { 42 }`. The `BlockNode` is `{ 42 }`. The actual code executed when calling method `foo` is `{ 42 }`, not `bar(1, 2, 3) { 42 }`. ---------------------------------------- Feature #21795: Methods for retrieving ASTs https://bugs.ruby-lang.org/issues/21795#change-118448 * Author: kddnewton (Kevin Newton) * Status: Closed ---------------------------------------- I would like to propose a handful of methods for retrieving ASTs from various objects that correspond to locations in code. This includes: * Proc#ast * Method#ast * UnboundMethod#ast * Thread::Backtrace::Location#ast * TracePoint#ast (on call/return events) The purpose of this is to make tooling easier to write and maintain. Specifically, this would be able to be used in irb, power_assert, error_highlight, and various other tools both in core and not that make use of source code. There have been many previous discussions of retrieving node_id, source_location, source, etc. All of these use cases are covered by returning the AST for some entity. In this case node_id becomes an implementation detail, invisible to the user. Source location can be derived from the information on the AST itself. Similarly, source can be derived from the AST. Internally, I do not think we have to store any more information than we already do (since we have node_id for the first four of these, it becomes rather trivial). For TracePoint we can have a larger discussion about it, but I think it should not be too much work. In terms of implementation, the only caveat I would put is that if the ISEQ were compiled through the old parser/compiler, this should return `nil`, as the node ids do not match up and we do not want to further propagate the RubyVM::AST API. The reason I am opening up this ticket with 5 different methods requested in it is to get approval first for the direction, then I can open individual tickets or just PRs for each method. I believe this feature would ease the maintenance burden of many core libraries, and unify otherwise disparate efforts to achieve the same thing. -- https://bugs.ruby-lang.org/