Add icu_preferences util

Cargo.toml

@@ -65,6 +65,7 @@ members = [
     "utils/ixdtf",
     "utils/litemap",
     "utils/pattern",
+    "utils/preferences",
     "utils/resb",
     "utils/tinystr",
     "utils/tzif",

components/locale_core/src/extensions/unicode/mod.rs

@@ -30,6 +30,7 @@ mod attribute;
 mod attributes;
 mod key;
 mod keywords;
+mod subdivision;
 mod value;
 
 use core::cmp::Ordering;
@@ -41,6 +42,7 @@ pub use attributes::Attributes;
 #[doc(inline)]
 pub use key::{key, Key};
 pub use keywords::Keywords;
+pub use subdivision::{subdivision_suffix, SubdivisionId, SubdivisionSuffix};
 #[doc(inline)]
 pub use value::{value, Value};
 

components/locale_core/src/extensions/unicode/subdivision.rs

@@ -0,0 +1,114 @@
+// This file is part of ICU4X. For terms of use, please see the file
+// called LICENSE at the top level of the ICU4X source tree
+// (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
+
+use core::str::FromStr;
+
+use crate::parser::ParserError;
+use crate::subtags::Region;
+
+impl_tinystr_subtag!(
+    /// An subdivision suffix used in a set of [`SubdivisionId`].
+    ///
+    /// An subdivision suffix has to be a sequence of alphanumerical characters no
+    /// shorter than one and no longer than four characters.
+    ///
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use icu::locid::extensions::unicode::{subdivision_suffix, SubdivisionSuffix};
+    ///
+    /// let ss: SubdivisionSuffix =
+    ///     "sct".parse().expect("Failed to parse a SubdivisionSuffix.");
+    ///
+    /// assert_eq!(ss, subdivision_suffix!("sct"));
+    /// ```
+    SubdivisionSuffix,
+    extensions::unicode,
+    subdivision_suffix,
+    extensions_unicode_subdivision_suffix,
+    1..=4,
+    s,
+    s.is_ascii_alphanumeric(),
+    s.to_ascii_lowercase(),
+    s.is_ascii_alphanumeric() && s.is_ascii_lowercase(),
+    InvalidExtension,
+    ["sct"],
+    ["toolooong"],
+);
+
+/// A SubDivision Id as defined in [`Unicode Locale Identifier`].
+///
+/// [`Unicode Locale Identifier`]: https://unicode.org/reports/tr35/tr35.html#unicode_subdivision_id
+///
+/// # Examples
+///
+/// ```
+/// ```
+#[derive(Debug, PartialEq, Eq, Clone, Hash, PartialOrd, Ord)]
+#[non_exhaustive]
+pub struct SubdivisionId {
+    #[doc(hidden)]
+    pub region: Region,
+    #[doc(hidden)]
+    pub suffix: SubdivisionSuffix,
+}
+
+impl SubdivisionId {
+    #[doc(hidden)]
+    pub const fn new(region: Region, suffix: SubdivisionSuffix) -> Self {
+        Self { region, suffix }
+    }
+
+    #[doc(hidden)]
+    pub fn try_from_bytes(input: &[u8]) -> Result<Self, ParserError> {
+        let is_alpha = if let Some(b) = input.first() {
+            if b.is_ascii_digit() {
+                false
+            } else if b.is_ascii_alphabetic() {
+                true
+            } else {
+                return Err(ParserError::InvalidExtension);
+            }
+        } else {
+            return Err(ParserError::InvalidExtension);
+        };
+        let region_len = if is_alpha { 2 } else { 3 };
+        if input.len() < region_len + 1 {
+            return Err(ParserError::InvalidExtension);
+        }
+        let (region_bytes, suffix_bytes) = input.split_at(region_len);
+        let region =
+            Region::try_from_bytes(region_bytes).map_err(|_| ParserError::InvalidExtension)?;
+        let suffix = SubdivisionSuffix::try_from_bytes(suffix_bytes)?;
+        Ok(Self { region, suffix })
+    }
+}
+
+impl writeable::Writeable for SubdivisionId {
+    #[inline]
+    fn write_to<W: core::fmt::Write + ?Sized>(&self, sink: &mut W) -> core::fmt::Result {
+        sink.write_str(self.region.as_str())?;
+        sink.write_str(self.suffix.as_str())
+    }
+
+    #[inline]
+    fn writeable_length_hint(&self) -> writeable::LengthHint {
+        todo!()
+    }
+    #[inline]
+    fn write_to_string(&self) -> alloc::borrow::Cow<str> {
+        todo!()
+    }
+}
+
+writeable::impl_display_with_writeable!(SubdivisionId);
+
+impl FromStr for SubdivisionId {
+    type Err = ParserError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Self::try_from_bytes(s.as_bytes())
+    }
+}

components/locale_core/src/extensions/unicode/value.rs

@@ -3,7 +3,7 @@
 // (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
 
 use crate::parser::{ParserError, SubtagIterator};
-use crate::shortvec::ShortBoxSlice;
+use crate::shortvec::{ShortBoxSlice, ShortBoxSliceIntoIter};
 use crate::subtags::{subtag, Subtag};
 use alloc::vec::Vec;
 use core::str::FromStr;
@@ -66,11 +66,48 @@ impl Value {
         self.0.single()
     }
 
+    #[doc(hidden)]
+    pub fn into_single_subtag(self) -> Option<Subtag> {
+        self.0.into_single()
+    }
+
     #[doc(hidden)]
     pub fn as_subtags_slice(&self) -> &[Subtag] {
         &self.0
     }
 
+    #[doc(hidden)]
+    pub fn push_subtag(&mut self, subtag: Subtag) {
+        self.0.push(subtag);
+    }
+
+    #[doc(hidden)]
+    pub fn extend(&mut self, rest: &Self) {
+        for i in rest.0.iter() {
+            self.0.push(*i);
+        }
+    }
+
+    #[doc(hidden)]
+    pub fn len(&self) -> usize {
+        self.0.len()
+    }
+
+    #[doc(hidden)]
+    pub fn remove_subtag(&mut self, idx: usize) -> Option<Subtag> {
+        if self.0.len() < idx {
+            None
+        } else {
+            let item = self.0.remove(idx);
+            Some(item)
+        }
+    }
+
+    #[doc(hidden)]
+    pub fn get_subtag(&self, idx: usize) -> Option<&Subtag> {
+        self.0.get(idx)
+    }
+
     #[doc(hidden)]
     pub const fn from_subtag(subtag: Option<Subtag>) -> Self {
         match subtag {
@@ -132,6 +169,22 @@ impl Value {
     }
 }
 
+impl IntoIterator for Value {
+    type Item = Subtag;
+
+    type IntoIter = ShortBoxSliceIntoIter<Subtag>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.0.into_iter()
+    }
+}
+
+impl FromIterator<Subtag> for Value {
+    fn from_iter<T: IntoIterator<Item = Subtag>>(iter: T) -> Self {
+        Self(ShortBoxSlice::from_iter(iter.into_iter()))
+    }
+}
+
 impl FromStr for Value {
     type Err = ParserError;
 

components/locale_core/src/shortvec/mod.rs

@@ -117,6 +117,17 @@ impl<T> ShortBoxSlice<T> {
         }
     }
 
+    /// Destruct into a single element of the [`ShortBoxSlice`].
+    ///
+    /// Returns `None` if empty or more than one element.
+    pub fn into_single(self) -> Option<T> {
+        use ShortBoxSliceInner::*;
+        match self.0 {
+            ZeroOne(Some(v)) => Some(v),
+            _ => None,
+        }
+    }
+
     /// Returns the number of elements in the collection.
     #[inline]
     pub fn len(&self) -> usize {

components/locale_core/src/subtags/mod.rs

@@ -96,6 +96,11 @@ impl Subtag {
         2 <= v.len() && v.len() <= 8
     }
 
+    #[doc(hidden)]
+    pub fn len(&self) -> usize {
+        self.0.len()
+    }
+
     #[doc(hidden)]
     pub fn from_tinystr_unvalidated(input: tinystr::TinyAsciiStr<8>) -> Self {
         Self(input)

components/locale_core/src/subtags/script.rs

@@ -2,6 +2,8 @@
 // called LICENSE at the top level of the ICU4X source tree
 // (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
 
+use crate::subtags::Subtag;
+
 impl_tinystr_subtag!(
     /// A script subtag (examples: `"Latn"`, `"Arab"`, etc.)
     ///
@@ -31,3 +33,10 @@ impl_tinystr_subtag!(
     ["Latn"],
     ["Latin"],
 );
+
+impl Script {
+    #[doc(hidden)]
+    pub fn into_subtag(self) -> Subtag {
+        Subtag(self.0.resize())
+    }
+}

utils/preferences/Cargo.toml

@@ -0,0 +1,29 @@
+# This file is part of ICU4X. For terms of use, please see the file
+# called LICENSE at the top level of the ICU4X source tree
+# (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
+
+[package]
+name = "icu_preferences"
+description = "API for resolving preferences"
+version = "0.0.1"
+categories = ["internationalization"]
+license-file = "LICENSE"
+
+authors.workspace = true
+edition.workspace = true
+include.workspace = true
+repository.workspace = true
+rust-version.workspace = true
+
+[package.metadata.workspaces]
+independent = true
+
+[package.metadata.docs.rs]
+all-features = true
+
+[dependencies]
+icu_locale_core = { workspace = true }
+tinystr = { workspace = true }
+
+[dev-dependencies]
+icu_datetime = { workspace = true }

utils/preferences/LICENSE

@@ -0,0 +1,44 @@
+UNICODE LICENSE V3
+
+COPYRIGHT AND PERMISSION NOTICE
+
+Copyright © 2020-2023 Unicode, Inc.
+
+NOTICE TO USER: Carefully read the following legal agreement. BY
+DOWNLOADING, INSTALLING, COPYING OR OTHERWISE USING DATA FILES, AND/OR
+SOFTWARE, YOU UNEQUIVOCALLY ACCEPT, AND AGREE TO BE BOUND BY, ALL OF THE
+TERMS AND CONDITIONS OF THIS AGREEMENT. IF YOU DO NOT AGREE, DO NOT
+DOWNLOAD, INSTALL, COPY, DISTRIBUTE OR USE THE DATA FILES OR SOFTWARE.
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of data files and any associated documentation (the "Data Files") or
+software and any associated documentation (the "Software") to deal in the
+Data Files or Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, and/or sell
+copies of the Data Files or Software, and to permit persons to whom the
+Data Files or Software are furnished to do so, provided that either (a)
+this copyright and permission notice appear with all copies of the Data
+Files or Software, or (b) this copyright and permission notice appear in
+associated Documentation.
+
+THE DATA FILES AND SOFTWARE ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF
+THIRD PARTY RIGHTS.
+
+IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS INCLUDED IN THIS NOTICE
+BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES,
+OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THE DATA
+FILES OR SOFTWARE.
+
+Except as contained in this notice, the name of a copyright holder shall
+not be used in advertising or otherwise to promote the sale, use or other
+dealings in these Data Files or Software without prior written
+authorization of the copyright holder.
+
+—
+
+Portions of ICU4X may have been adapted from ICU4C and/or ICU4J.
+ICU 1.8.1 to ICU 57.1 © 1995-2016 International Business Machines Corporation and others.