Instead of accessing the struct as an array, access it via methods. There are other places inside of this file already using this API (for example e0a5c3d2b7/lib/irb/ruby-lex.rb (L829-L830)).
This commit moves all struct array-ish calls to use their method calls instead. It is also ~1.23 faster accessing values via a method instead of as an array according to this microbenchmark:
```ruby
Elem = Struct.new(:pos, :event, :tok, :state, :message) do
def initialize(pos, event, tok, state, message = nil)
super(pos, event, tok, State.new(state), message)
end
# ...
def to_a
a = super
a.pop unless a.empty?
a
end
end
class ElemClass
attr_accessor :pos, :event, :tok, :state, :message
def initialize(pos, event, tok, state, message = nil)
@pos = pos
@event = event
@tok = tok
@state = State.new(state)
@message = message
end
def to_a
if @message
[@pos, @event, @tok, @state, @message]
else
[@pos, @event, @tok, @state]
end
end
end
# stub state class creation for now
class State; def initialize(val); end; end
```
```ruby
Benchmark.ips do |x|
x.report("struct") { struct[1] }
x.report("class ") { from_class.event }
x.compare!
end; nil
```
```
Warming up --------------------------------------
struct 1.624M i/100ms
class 1.958M i/100ms
Calculating -------------------------------------
struct 17.139M (± 2.6%) i/s - 86.077M in 5.025801s
class 21.104M (± 3.4%) i/s - 105.709M in 5.015193s
Comparison:
class : 21103826.3 i/s
struct: 17139201.5 i/s - 1.23x (± 0.00) slower
```
This reverts commit 27dd2867cda5c789efaa5078214ad2fd82adcebf.
This is to fix the test I added.
(I separated commits to test a new behavior of ruby-commit-hook)
fe055d521a
https://github.com/ruby/irb/pull/249 actually slowed down how `code` is
concatenated. The original way of creating `code` is faster.
[before]
user system total real
2.420137 0.005364 2.425501 ( 2.426264)
[after]
user system total real
1.000221 0.007454 1.007675 ( 1.008295)
Theoretically, this implementation might skip lines that don't appear in
Ripper tokens, but this assumes such lines don't impact whether the code
passes compilation or not. At least normal blank lines seem to have an
`on_ignored_nl` token anyway though.
27dd2867cd