Replacing chain(core::iter::once(x)) by chain([x]) (#3419)

unicode-org · May 9, 2023 · 8e389a5 · 8e389a5
1 parent 458e536
commit 8e389a5
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Showing 5 changed files with 6 additions and 11 deletions.
diff --git a/provider/datagen/src/lib.rs b/provider/datagen/src/lib.rs
@@ -227,9 +227,7 @@ pub fn key<S: AsRef<str>>(string: S) -> Option<DataKey> {
  lazy_static::lazy_static! {
  static ref LOOKUP: std::collections::HashMap<&'static str, DataKey> = all_keys_with_experimental()
  .into_iter()
- .chain(std::iter::once(
- icu_provider::hello_world::HelloWorldV1Marker::KEY,
- ))
+ .chain([icu_provider::hello_world::HelloWorldV1Marker::KEY])
  .map(|k| (k.path().get(), k))
  .collect();
  }
@@ -452,7 +450,7 @@ pub fn datagen(
  LocaleInclude::Explicit(
  ls.iter()
  .cloned()
- .chain(core::iter::once(icu_locid::LanguageIdentifier::UND))
+ .chain([icu_locid::LanguageIdentifier::UND])
  .collect(),
  )
  })

diff --git a/provider/datagen/src/transform/cldr/decimal/mod.rs b/provider/datagen/src/transform/cldr/decimal/mod.rs
@@ -97,7 +97,7 @@ impl crate::DatagenProvider {
  );
  data_locale
  })
- .chain(core::iter::once(last))
+ .chain([last])
  })
  .collect(),
  ))

diff --git a/tools/testdata-scripts/src/bin/make-testdata.rs b/tools/testdata-scripts/src/bin/make-testdata.rs
@@ -65,9 +65,7 @@ fn main() {
  Some(LOCALES),
  &icu_datagen::all_keys_with_experimental()
  .into_iter()
- .chain(core::iter::once(
- icu_provider::hello_world::HelloWorldV1Marker::KEY,
- ))
+ .chain([icu_provider::hello_world::HelloWorldV1Marker::KEY])
  .collect::<Vec<_>>(),
  &source,
  vec![json_out, blob_out, mod_out, postcard_out],

diff --git a/utils/zerovec/src/flexzerovec/slice.rs b/utils/zerovec/src/flexzerovec/slice.rs
@@ -298,8 +298,7 @@ impl FlexZeroSlice {
  /// assert_eq!(pairs_it.next(), None);
  /// ```
  pub fn iter_pairs(&self) -> impl Iterator<Item = (usize, Option<usize>)> + '_ {
- self.iter()
- .zip(self.iter().skip(1).map(Some).chain(core::iter::once(None)))
+ self.iter().zip(self.iter().skip(1).map(Some).chain([None]))
  }
 
  /// Creates a `Vec<usize>` from a [`FlexZeroSlice`] (or `FlexZeroVec`).

diff --git a/utils/zerovec/src/varzerovec/components.rs b/utils/zerovec/src/varzerovec/components.rs
@@ -369,7 +369,7 @@ impl<'a, T: VarULE + ?Sized, F: VarZeroVecFormat> VarZeroVecComponents<'a, T, F>
  .copied()
  .map(F::rawbytes_to_usize)
  .skip(1)
- .chain(core::iter::once(self.things.len())),
+ .chain([self.things.len()]),
  )
  .map(move |(start, end)| unsafe { self.things.get_unchecked(start..end) })
  .map(|bytes| unsafe { T::from_byte_slice_unchecked(bytes) })