Issue #21998 has been updated by mame (Yusuke Endoh). Eregon (Benoit Daloze) wrote in #note-7:
We can easily compute the end of heredoc if the API returns `}`
How do you determine whether a block contains a heredoc? Consider: - `{ <<X }`: heredoc - `{ x<<X }`: shift operator - `{ x <<X }`: heredoc Of course, you also have to handle `<<"X"`, and `"<<X"` is a string literal, and you have to consider cases like `{ <<"X" + <<"Y" }`. Even once you have identified a heredoc, finding its end delimiter is not trivial either: ``` <<"X" #{ X } X ``` Here the end delimiter is the `X` on line 5, because `#{` opens an interpolation. ``` <<'X' #{ X } X ``` Here the end delimiter is the `X` on line 3, because single-quoted heredocs do not interpolate, so `#{` is literal text. I cannot see how any of this is "easily computed". ---------------------------------------- Feature #21998: Add {Method,UnboundMethod,Proc}#source_range https://bugs.ruby-lang.org/issues/21998#change-117074 * Author: Eregon (Benoit Daloze) * Status: Open ---------------------------------------- I'm using matz's suggestion almost as-is from https://bugs.ruby-lang.org/issues/6012#note-53. The only change is the proposed class name. ## Use Cases Use cases have been discussed extensively and matz said:
The use cases are real and I want to support them
So I think we don't need to discuss that anymore :) ## Background Adding column and last line information to `#source_location` is deemed too incompatible given the usages of `obj.source_location.last` which expect the start line (they would get the end column instead). ## Proposal So instead we add a new method, `{Method,UnboundMethod,Proc}#source_range`, which returns a `Ruby::SourceRange` and has these methods: * `start_line`: 1-indexed (same as `source_location.first`) * `end_line`: 1-indexed * `start_column`: in bytes, 0-indexed, I think `start_byte_column` could be good for extra clarity * `end_column`: in bytes, 0-indexed, I think `end_byte_column` could be good for extra clarity * `inspect` which shows something like `#<Ruby::SourceRange (1,0)-(2,10)>`. For the edge case of a heredoc spanning further than the end of a method/block, we would not include it in the `end_line` & `end_column` methods, but instead document it and provide a small code snippet in the docs to compute that if desired with Prism. ## Alternative An alternative could be a `Ruby::SourceLocation` class and `obj.source_location(object: true)`/`obj.source_location(extended: true)` but it feels less nice. Since we are designing something new I think it's best to go for the cleanest design. ## Consistency The above methods match the name of methods on `Prism::Node` and have the same semantics, which is good for consistency and to avoid confusion. ## Scope The scope is intentionally minimal to keep the discussion focused. ## Implementation I'm happy to implement this, it should be pretty trivial and very similar to the extended `source_location`. I would prefer to get an approval for this feature before implementing. -- https://bugs.ruby-lang.org/