Modernizing parts of Option, Result, and Default #9115
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It seems the docs for |
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| use std::vec; | ||
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| pub fn expand_deriving_default(cx: @ExtCtxt, |
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Could you add a mention of this new one to the "deriving" section of the manual?
Vecs are not numeric types, so it doesn't make sense for them to implement Zero.
Options are not numeric types, so it doesn't make sense for them to implement Zero.
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| /// Returns self or `Some`-wrapped default value | ||
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| pub fn or_default(self) -> Option<T> { |
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Is this x.or_default() different to Some(x.unwrap_or_default())? (Is it worth having a function just for this?)
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Look at that. I added it because we already had .or_zero. I'll remove .or_default and .or_zero in a separate PR since this one is getting pretty weighty already.
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This looks fine to me from a code point-of-view, but it feels like a significant addition of code that should be also approved by someone who's not me. Also, cc #9157. |
This is a series of patches to modernize option and result. The highlights are: * rename `.unwrap_or_default(value)` and etc to `.unwrap_or(value)` * add `.unwrap_or_default()` that uses the `Default` trait * add `Default` implementations for vecs, HashMap, Option * add `Option.and(T) -> Option<T>`, `Option.and_then(&fn() -> Option<T>) -> Option<T>`, `Option.or(T) -> Option<T>`, and `Option.or_else(&fn() -> Option<T>) -> Option<T>` * add `option::ToOption`, `option::IntoOption`, `option::AsOption`, `result::ToResult`, `result::IntoResult`, `result::AsResult`, `either::ToEither`, and `either::IntoEither`, `either::AsEither` * renamed `Option::chain*` and `Result::chain*` to `and_then` and `or_else` to avoid the eventual collision with `Iterator.chain`. * Added a bunch of impls of `Default` * Added a `#[deriving(Default)]` syntax extension * Removed impls of `Zero` for `Option<T>` and vecs.
…logiq `new_without_default`: ignore const generics/lifetime params on `fn new` Fixes rust-lang#9113 No longer lints if `fn new` has any params changelog: [`new_without_default`]: no longer lints const generics and lifetime params on `fn new`
This is a series of patches to modernize option and result. The highlights are:
.unwrap_or_default(value)and etc to.unwrap_or(value).unwrap_or_default()that uses theDefaulttraitDefaultimplementations for vecs, HashMap, OptionOption.and(T) -> Option<T>,Option.and_then(&fn() -> Option<T>) -> Option<T>,Option.or(T) -> Option<T>, andOption.or_else(&fn() -> Option<T>) -> Option<T>option::ToOption,option::IntoOption,option::AsOption,result::ToResult,result::IntoResult,result::AsResult,either::ToEither, andeither::IntoEither,either::AsEitherOption::chain*andResult::chain*toand_thenandor_elseto avoid the eventual collision withIterator.chain.Default#[deriving(Default)]syntax extensionZeroforOption<T>and vecs.