[ruby-core:79467] [CommonRuby Feature#12732] An option to pass to `Integer`, `Float`, to return `nil` instead of raise an exception

Issue #12732 has been updated by Jan Lelis.


Although it does not solve Aaron's use case, I would suggest to have a `Integer.try_convert`, `Float.try_convert`, `Rational.try_convert`, and `Complex.try_convert` which do not raise exceptions, but just return `nil`. To keep consistency, they would just call implicit, then explicit conversion (e.g. `to_int`, then `to_i`), instead of `Integer()`'s special parsing.

It only allows strict parsing, but is much cleaner, imho. Also, it would fill some empty spots in the [core conversion table](http://idiosyncratic-ruby.com/54-try-converting.html#core-classes-conversion-table) and make Ruby's conversion logic simpler. (`.try_convert`, which currently feels more like an implementation detail, could then be embraced more).

To allow `Integer()` special conversion, it would still need an `exception:` option, but also `Float()`, `Rational()`, and `Complex()` would need it (since they currently also lack this feature due to not having a `try_convert`). One idea is to give every of the uppercased Kernel methods an `exception:` option, but this does not make sense for `Array()` and just would not be needed if going for the broader `try_convert` support).

To summarize my suggestion in two bullet points:

- Create `Integer.try_convert`, `Float.try_convert`, `Rational.try_convert`, and `Complex.try_convert` which prefer implicit conversion (if available), then explicit conversion, but return `nil` instead of raising an exception
- Give `Integer()` an `exception` option to support special integer parsing without exceptions, but do not give `Float()` one

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Feature #12732: An option to pass to `Integer`, `Float`, to return `nil` instead of raise an exception
https://bugs.ruby-lang.org/issues/12732#change-62897

* Author: Aaron Patterson
* Status: Feedback
* Priority: Normal
* Assignee: Yukihiro Matsumoto
* Target version: 
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I would like to be able to pass an option to `Integer()` and `Float()` so that they don't raise an exception, but return `nil` instead.  For example:

~~~
Integer(string, exception: false)
~~~

The reason I want this function is so that I can convert strings from YAML or JSON to integers if they parse correctly, or just return strings if they can't be parsed.

---Files--------------------------------
integer-parse.pdf (29 KB)


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