[#107430] [Ruby master Feature#18566] Merge `io-wait` gem into core IO — "byroot (Jean Boussier)" <noreply@...>
Issue #18566 has been reported by byroot (Jean Boussier).
22 messages
2022/02/02
[ruby-core:107704] [Ruby master Feature#18597] Strings need a named method like `dup` that doesn't duplicate if receiver is mutable
From:
"Dan0042 (Daniel DeLorme)" <noreply@...>
Date:
2022-02-21 23:48:37 UTC
List:
ruby-core #107704
Issue #18597 has been updated by Dan0042 (Daniel DeLorme).
As I'm sure you realize, after the loop the buffer would still be empty; text is concatenated to a dup'ed buffer that is then thrown away. What's the point of that? You'd need to use `buffer = add_result_text(buffer, result)` in the loop, but at that point it would be simpler to just have a mutable buffer to start with: `buffer = +""`. And chaining doesn't even pose a precedence problem; if you use `+buffer << text` it's perfectly readable. So I find this example very unconvincing.
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Feature #18597: Strings need a named method like `dup` that doesn't duplicate if receiver is mutable
https://bugs.ruby-lang.org/issues/18597#change-96622
* Author: danh337 (Dan H)
* Status: Open
* Priority: Normal
----------------------------------------
This is related to #16295, but focuses only on the `.+@` part.
Currently we can use `.dup` in a method chain when we need to mutate a String.
However there are cases where the code's context *expects* the String to be mutated. In cases like this, `.dup` always works, but we don't want to duplicate a String that is already mutable.
Since `.+@` looks more like an operator, it can be unintuitive in a method chain, so this is asking for a new named method that can be used in its place, instead of always `.dup`.
For example:
```
def add_result_text(buffer, new_result)
text = "#{new_result.count} #{new_result.input} #{do_fancy_calc(new_result)}\n"
buffer.dup_if_immutable << text
# ^^^^^^^^^^^^^^^^ new method?
end
buffer = "" # ...maybe immutable
get_lots_of_results.each do |result|
add_result_text(buffer, result)
end
```
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