From: "mame (Yusuke Endoh) via ruby-core" <ruby-core@...>
Date: 2026-04-18T04:29:56+00:00
Subject: [ruby-core:125321] [Ruby Feature#21998] Add {Method,UnboundMethod,Proc}#source_range

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.



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