Add FixedDecimalFormat data provider plumbing

Cargo.toml

@@ -8,6 +8,7 @@ members = [
     "experimental/bies",
     "experimental/segmenter_lstm",
     "components/datetime",
+    "components/decimal",
     "components/ecma402",
     "components/capi",
     "components/icu",

Makefile.toml

@@ -177,6 +177,7 @@ args = [
     "--",
     "--cldr-core", "../../resources/testdata/data/cldr/cldr-core",
     "--cldr-dates", "../../resources/testdata/data/cldr/cldr-dates-full",
+    "--cldr-numbers", "../../resources/testdata/data/cldr/cldr-numbers-full",
     "--out", "../../resources/testdata/data/bincode",
     "--all-keys",
     "-s", "bincode",

components/decimal/Cargo.toml

@@ -0,0 +1,33 @@
+# 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_decimal"
+version = "0.1.0"
+authors = ["The ICU4X Project Developers"]
+edition = "2018"
+repository = "https://github.com/unicode-org/icu4x"
+license-file = "../../LICENSE"
+categories = ["internationalization"]
+include = [
+    "src/**/*",
+    "benches/**/*",
+    "Cargo.toml",
+    "README.md"
+]
+
+[package.metadata.cargo-all-features]
+skip_optional_dependencies = true
+
+[dependencies]
+smallstr = { version = "0.2", features = ["serde"] }
+icu_locid = { version = "0.1", path = "../locid" }
+icu_provider = { version = "0.1", path = "../provider" }
+serde = { version = "1.0", features = ["derive"], optional = true }
+
+[features]
+default = ["provider_serde"]
+bench = []
+provider_serde = ["serde"]
+serialize_none = []

components/decimal/README.md

@@ -0,0 +1,12 @@
+`icu_decimal` offers localized decimal number formatting.
+
+It will eventually support:
+
+- Plain decimal numbers
+- Currencies
+- Measurement units
+- Compact notation
+
+Currently, the crate is a work in progress with extremely limited functionality. To track progress, follow this issue:
+
+https://github.com/unicode-org/icu4x/issues/275

components/decimal/src/lib.rs

@@ -0,0 +1,19 @@
+// 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 ).
+
+//! `icu_decimal` offers localized decimal number formatting.
+//!
+//! It will eventually support:
+//!
+//! - Plain decimal numbers
+//! - Currencies
+//! - Measurement units
+//! - Compact notation
+//!
+//! Currently, the crate is a work in progress with extremely limited functionality. To track
+//! progress, follow this issue:
+//!
+//! https://github.com/unicode-org/icu4x/issues/275
+
+pub mod provider;

components/decimal/src/provider.rs

@@ -0,0 +1,76 @@
+// 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 ).
+
+//! Data provider struct definitions for `icu_decimal`.
+//!
+//! Read more about data providers: [icu_provider]
+
+pub type SmallString8 = smallstr::SmallString<[u8; 8]>;
+
+pub mod key {
+    //! Resource keys for `icu_decimal`.
+    use icu_provider::{resource_key, ResourceKey};
+
+    /// Resource key: symbols used for basic decimal formatting.
+    pub const SYMBOLS_V1: ResourceKey = resource_key!(decimal, "symbols", 1);
+}
+
+/// A collection of strings to affix to a decimal number.
+#[derive(Debug, PartialEq, Clone)]
+#[cfg_attr(
+    feature = "provider_serde",
+    derive(serde::Serialize, serde::Deserialize)
+)]
+pub struct AffixesV1 {
+    /// String to prepend before the decimal number.
+    pub prefix: SmallString8,
+
+    /// String to append after the decimal number.
+    pub suffix: SmallString8,
+}
+
+/// A collection of settings expressing where to put grouping separators in a decimal number.
+/// For example, `1,000,000` has two grouping separators, positioned along every 3 digits.
+#[derive(Debug, PartialEq, Clone)]
+#[cfg_attr(
+    feature = "provider_serde",
+    derive(serde::Serialize, serde::Deserialize)
+)]
+pub struct GroupingSizesV1 {
+    /// The size of the first (lowest-magnitude) group.
+    pub primary: u8,
+
+    /// The size of groups after the first group.
+    pub secondary: u8,
+
+    /// The minimum number of digits required before the first group. For example, if `primary=3`
+    /// and `min_grouping=2`, grouping separators will be present on 10,000 and above.
+    pub min_grouping: u8,
+}
+
+/// Symbols and metadata required for formatting a FixedDecimal.
+#[derive(Debug, PartialEq, Clone)]
+#[cfg_attr(
+    feature = "provider_serde",
+    derive(serde::Serialize, serde::Deserialize)
+)]
+pub struct DecimalSymbolsV1 {
+    /// Prefix and suffix to apply when a negative sign is needed.
+    pub minus_sign_affixes: AffixesV1,
+
+    /// Prefix and suffix to apply when a plus sign is needed.
+    pub plus_sign_affixes: AffixesV1,
+
+    /// Character used to separate the integer and fraction parts of the number.
+    pub decimal_separator: SmallString8,
+
+    /// Character used to separate groups in the integer part of the number.
+    pub grouping_separator: SmallString8,
+
+    /// Settings used to determine where to place groups in the integer part of the number.
+    pub grouping_sizes: GroupingSizesV1,
+
+    /// Zero digit for the current numbering system.
+    pub zero_digit: char,
+}

components/provider/src/resource.rs

@@ -22,6 +22,7 @@ pub enum ResourceCategory {
     Plurals,
     Dates,
     Uniset,
+    Decimal,
     PrivateUse(TinyStr4),
 }
 
@@ -34,6 +35,7 @@ impl ResourceCategory {
             Self::Plurals => Cow::Borrowed("plurals"),
             Self::Dates => Cow::Borrowed("dates"),
             Self::Uniset => Cow::Borrowed("uniset"),
+            Self::Decimal => Cow::Borrowed("decimal"),
             Self::PrivateUse(id) => {
                 let mut result = String::from("x-");
                 result.push_str(id.as_str());
@@ -106,6 +108,9 @@ macro_rules! resource_key {
     (uniset, $sub_category:literal, $version:tt) => {
         $crate::resource_key!($crate::ResourceCategory::Uniset, $sub_category, $version)
     };
+    (decimal, $sub_category:literal, $version:tt) => {
+        $crate::resource_key!($crate::ResourceCategory::Decimal, $sub_category, $version)
+    };
     (x, $pu:literal, $sub_category:literal, $version:tt) => {
         $crate::resource_key!(
             $crate::ResourceCategory::PrivateUse($crate::internal::tinystr4!($pu)),

components/provider_cldr/Cargo.toml

@@ -33,13 +33,17 @@ icu_locid = { version = "0.1", path = "../locid" }
 icu_plurals = { version = "0.1", path = "../plurals" }
 icu_datetime = { version = "0.1", path = "../datetime" }
 icu_locale_canonicalizer = { version = "0.1", path = "../locale_canonicalizer" }
+icu_decimal = { version = "0.1", path = "../decimal" }
+itertools = "0.10"
 json = "0.12"
+litemap = { version = "0.1.1", path = "../../utils/litemap" }
 serde = { version = "1.0", features = ["derive"] }
+serde-aux = "2.1.1"
 serde_json = "1.0"
 serde-tuple-vec-map = "1.0"
-tinystr = "0.4"
+smallstr = { version = "0.2", features = ["serde"] }
 smallvec = "1.4"
-litemap = { version = "0.1.1", path = "../../utils/litemap" }
+tinystr = { version = "0.4.3", features = ["serde"] }
 
 # Dependencies for the download feature
 urlencoding = { version = "1.1", optional = true }

components/provider_cldr/src/error.rs

@@ -2,6 +2,7 @@
 // called LICENSE at the top level of the ICU4X source tree
 // (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
 
+use icu_locid::LanguageIdentifier;
 use std::error;
 use std::fmt;
 use std::path::{Path, PathBuf};
@@ -14,6 +15,7 @@ use crate::download;
 pub enum Error {
     Io(std::io::Error, Option<PathBuf>),
     Json(serde_json::error::Error, Option<PathBuf>),
+    Custom(String, Option<LanguageIdentifier>),
     MissingSource(MissingSourceError),
     #[cfg(feature = "download")]
     Download(download::Error),
@@ -47,6 +49,22 @@ impl<P: AsRef<Path>> From<(serde_json::error::Error, P)> for Error {
     }
 }
 
+/// To help with debugging, string errors should be paired with a locale.
+/// If a locale is unavailable, create the error directly: `Error::Custom(err, None)`
+impl<L: AsRef<LanguageIdentifier>> From<(String, L)> for Error {
+    fn from(pieces: (String, L)) -> Self {
+        Self::Custom(pieces.0, Some(pieces.1.as_ref().clone()))
+    }
+}
+
+/// To help with debugging, string errors should be paired with a locale.
+/// If a locale is unavailable, create the error directly: `Error::Custom(err, None)`
+impl<L: AsRef<LanguageIdentifier>> From<(&'static str, L)> for Error {
+    fn from(pieces: (&'static str, L)) -> Self {
+        Self::Custom(pieces.0.to_string(), Some(pieces.1.as_ref().clone()))
+    }
+}
+
 impl From<MissingSourceError> for Error {
     fn from(err: MissingSourceError) -> Self {
         Self::MissingSource(err)
@@ -68,10 +86,10 @@ impl fmt::Display for Error {
         match self {
             Self::Io(err, Some(path)) => write!(f, "{}: {:?}", err, path),
             Self::Io(err, None) => err.fmt(f),
-            Self::Json(err, Some(filename)) => {
-                write!(f, "JSON parse error: {}: {:?}", err, filename)
-            }
-            Self::Json(err, None) => write!(f, "JSON parse error: {}", err),
+            Self::Json(err, Some(path)) => write!(f, "JSON error: {}: {:?}", err, path),
+            Self::Json(err, None) => write!(f, "JSON error: {}", err),
+            Self::Custom(s, Some(langid)) => write!(f, "{}: {:?}", s, langid),
+            Self::Custom(s, None) => write!(f, "{}", s),
             Self::MissingSource(err) => err.fmt(f),
             #[cfg(feature = "download")]
             Self::Download(err) => err.fmt(f),