[ruby-dev:52064] [Ruby master Feature#16142] Implement code_range in Proc and Method

Issue #16142 has been updated by okuramasafumi (Masafumi OKURA). Hi I noticed we didn't get any conclusion on this topic. I agree that method name should be something different. It follows the Matz's question: "What do we need from the method? line numbers? offset? whatever? " https://docs.ruby-lang.org/en/master/IO.html#method-c-read And we have `IO.read` method that accepts `length` and `offset` parameter. Since it's expected to be used with `IO.read`, it is convenient to return these two values. And Matz says And I agree. So the return value could be either Array or Hash. I think Hash is better than Array in this case because the value such as `[19, 10]` doesn't make sense itself. So what would be a good name? The combination of length and offset doesn't have a specific name as far as I know. What about `location` if `Proc` has this method? The final version would look like this. ```ruby my_proc = proc do do_something end loc = my_proc.location p loc # => {length:10, offset:19} maybe wrong number p File.read(__FILE__, loc[:length], loc[:offset]) # => do_something ``` ---------------------------------------- Feature #16142: Implement code_range in Proc and Method https://bugs.ruby-lang.org/issues/16142#change-106122 * Author: okuramasafumi (Masafumi OKURA) * Status: Open * Priority: Normal ---------------------------------------- # Abstract Add a new method `code_range` as an alternative to `source_location` to Proc and Method # Background I'd like to get a body from a Proc in TraceLocation gem (https://github.com/yhirano55/trace_location), in order to add what's executed to the output. There's no way to do that in current Ruby implementation, so as an alternative, I considered getting source code location of a Proc. # Proposal I propose that `Proc#code_range` and `Method#code_range`. Other names can work as well, for example `Proc#source_region`. It returns an array containing filename as a first argument and position information as a second array. For example: `a_proc.position # => [(irb), [1, 5, 3, 25]]` # Implementation I've implemented a simpler version of this, see gist for more details. https://gist.github.com/okuramasafumi/ac90bbf04a1c13b7d67954c9c5e62553 Notice I use `code_location` from iseq struct. # Discussion One might say that we can simply add columns and end position to Proc#source_location. However, this can easily brake existing apps such as Pry. It's also possible that we add additional keyword argument to `Proc#source_location`, for instance: `a_proc.source_location(including_range: true)` This change can also break existing apps since in old Rubies this keyword argument cannot be accepted. Therefore, adding a new method is better in terms of backward compatibility. It might be better at readability as well. # Summary I propose an API to get code position of Proc and Method so that we can get body of them (especially of a Proc). -- https://bugs.ruby-lang.org/