17 Apr
2023
17 Apr
'23
11:48 a.m.
Issue #19392 has been updated by zverok (Victor Shepelev).
@matz With all due respect, I don't believe the current behaviour is acceptable.
Considering the behaviour affects not only control flow `and`/`or` (relatively rarely
used), but also simple `if` (https://bugs.ruby-lang.org/issues/19392#note-7), I believe
the behaviour should be considered a bug.
I don't believe the fix lies in changing priorities of some operators, rather in
adjustment of endless methods parsing so **everything till the end of the line** (or
expression, if some way of linebreaking used) would be considered the body of such method,
always.
I don't believe it to be impossible, but due to obvious reasons can't experiment
with implementation myself currently.
I should say though that this behaviour would always be perceived as a bug, and I believe
can have an effect on Ruby's reputation, when one of the "cool new features"
behaves in an obviously wrong way.
----------------------------------------
Bug #19392: Endless method vs and/or
https://bugs.ruby-lang.org/issues/19392#change-102836
* Author: zverok (Victor Shepelev)
* Status: Closed
* Priority: Normal
* Backport: 2.7: DONTNEED, 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN
----------------------------------------
[Discovered](https://twitter.com/lucianghinda/status/1617783952353406977) by Lucian
Ghinda:
```ruby
def test = puts("foo") and puts("bar")
# prints "bar" immediately
test
# prints "foo"
```
It seems that it is a parser error, right?..
```ruby
RubyVM::AbstractSyntaxTree.parse('def test = puts("foo") and
puts("bar")')
# =>
# (SCOPE@1:0-1:38
# tbl: []
# args: nil
# body:
# (AND@1:0-1:38
# (DEFN@1:0-1:22
# mid: :test
# body:
# (SCOPE@1:0-1:22
# tbl: []
# args:
# (ARGS@1:0-1:8 pre_num: 0 pre_init: nil opt: nil first_post: nil post_num: 0
post_init: nil rest: nil kw: nil kwrest: nil block: nil)
# body: (FCALL@1:11-1:22 :puts (LIST@1:16-1:21 (STR@1:16-1:21 "foo")
nil))))
# (FCALL@1:27-1:38 :puts (LIST@1:32-1:37 (STR@1:32-1:37 "bar") nil))))
```
E.g. it is parsed as
```ruby
(def test = puts("foo")) and (puts("bar"))
```
...which is hardly intentional or have any practical use. The rightly parsed code in this
case _can_ have practical use, like
```ruby
def write(data) = File.write(@filename, data) == data.size or raise "Something went
wrong"
```
--
https://bugs.ruby-lang.org/