Feature #16684
Updated by sawa (Tsuyoshi Sawada) over 4 years ago
The most-recent-call-last order of backtrace introduced by #8661:
```ruby
def a; raise end
def b; a end
def c; b end
c
```
```
Traceback (most recent call last):
3: from foo.rb:4:in `<main>'
2: from foo.rb:3:in `c'
1: from foo.rb:2:in `b'
foo.rb:1:in `a': unhandled exception
```
is intuitive, and I hope it is retained. However, there are people complaining that it is confusing. I believe the unnaturalness is (at least partly) due to the fact that the word "from" is used, which made sense when backtrace was displayed in most-recent-call-first order,
```
foo.rb:1:in `a': unhandled exception
1: from foo.rb:2:in `b'
2: from foo.rb:3:in `c'
3: from foo.rb:4:in `<main>'
```
but not any more. Here, my understanding is that "from" means that the previous line was called **from** that line.
I propose that, so long as the most-recent-call-last order is adopted, the word "to" should be used rather than "from":
```
Traceback (most recent call last):
3: to foo.rb:4:in `<main>'
2: to foo.rb:3:in `c'
1: to foo.rb:2:in `b'
foo.rb:1:in `a': unhandled exception
```
Or, as an alternative, if it looks unnatural to have "to" in the first line, and to lack one before the message line, we may put it at the end of a line:
```
Traceback (most recent call last)
3: foo.rb:4:in `<main>' to:
2: foo.rb:3:in `c' to:
1: foo.rb:2:in `b' to:
foo.rb:1:in `a': unhandled exception
```
By using different words, it would become easier to understand the display order at a glance, and even by just looking at a single line.