Add support for the Gregorian Calendar availableFormats

components/datetime/Cargo.toml

@@ -28,6 +28,7 @@ icu_provider = { version = "0.1", path = "../provider" }
 writeable = { version = "0.2", path = "../../utils/writeable" }
 tinystr = { version = "0.4.1" }
 serde = { version = "1.0", features = ["derive"], optional = true }
+smallvec = "1.4"
 
 [dev-dependencies]
 criterion = "0.3"
@@ -37,6 +38,7 @@ icu_testdata = { version = "0.1", path = "../../resources/testdata" }
 icu_locid_macros = { version = "0.1", path = "../locid/macros" }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
+bincode = "1.3"
 
 [lib]
 bench = false  # This option is required for Benchmark CI

components/datetime/src/fields/length.rs

@@ -3,12 +3,16 @@
 // (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
 use std::convert::TryFrom;
 
-#[derive(Debug)]
+#[derive(Debug, PartialEq)]
 pub enum LengthError {
     TooLong,
 }
 
 #[derive(Debug, PartialEq, Clone, Copy)]
+#[cfg_attr(
+    feature = "provider_serde",
+    derive(serde::Serialize, serde::Deserialize)
+)]
 pub enum FieldLength {
     One = 1,
     TwoDigit = 2,

components/datetime/src/fields/mod.rs

@@ -2,9 +2,9 @@
 // called LICENSE at the top level of the ICU4X source tree
 // (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
 mod length;
-mod symbols;
+pub(crate) mod symbols;
 
-pub use length::FieldLength;
+pub use length::{FieldLength, LengthError};
 pub use symbols::*;
 
 use std::convert::{TryFrom, TryInto};
@@ -15,13 +15,15 @@ pub enum Error {
 }
 
 #[derive(Debug, PartialEq, Clone, Copy)]
+#[cfg_attr(
+    feature = "provider_serde",
+    derive(serde::Serialize, serde::Deserialize)
+)]
 pub struct Field {
     pub symbol: FieldSymbol,
     pub length: FieldLength,
 }
 
-impl Field {}
-
 impl From<(FieldSymbol, FieldLength)> for Field {
     fn from(input: (FieldSymbol, FieldLength)) -> Self {
         Self {

components/datetime/src/fields/symbols.rs

@@ -3,7 +3,7 @@
 // (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
 use std::convert::TryFrom;
 
-#[derive(Debug)]
+#[derive(Debug, PartialEq)]
 pub enum SymbolError {
     /// Unknown field symbol
     Unknown(u8),
@@ -12,6 +12,10 @@ pub enum SymbolError {
 }
 
 #[derive(Debug, PartialEq, Clone, Copy)]
+#[cfg_attr(
+    feature = "provider_serde",
+    derive(serde::Serialize, serde::Deserialize)
+)]
 pub enum FieldSymbol {
     Year(Year),
     Month(Month),
@@ -23,6 +27,43 @@ pub enum FieldSymbol {
     Second(Second),
 }
 
+impl FieldSymbol {
+    /// Skeletons are a Vec<Field>, and represent the Fields that can be used to match to a
+    /// specific pattern. The order of the Vec does not affect the Pattern that is output.
+    /// However, it's more performant when matching these fields, and it's more deterministic
+    /// when serializing them to present them in a consistent order.
+    ///
+    /// This ordering is taken by the order of the fields listed in the [UTS 35 Date Field Symbol Table]
+    /// (https://unicode.org/reports/tr35/tr35-dates.html#Date_Field_Symbol_Table), and are generally
+    /// ordered most significant to least significant.
+    ///
+    pub fn get_canonical_order(&self) -> u8 {
+        match self {
+            FieldSymbol::Year(Year::Calendar) => 0,
+            FieldSymbol::Year(Year::WeekOf) => 1,
+            FieldSymbol::Month(Month::Format) => 2,
+            FieldSymbol::Month(Month::StandAlone) => 3,
+            FieldSymbol::Day(Day::DayOfMonth) => 4,
+            FieldSymbol::Day(Day::DayOfYear) => 5,
+            FieldSymbol::Day(Day::DayOfWeekInMonth) => 6,
+            FieldSymbol::Day(Day::ModifiedJulianDay) => 7,
+            FieldSymbol::Weekday(Weekday::Format) => 8,
+            FieldSymbol::Weekday(Weekday::Local) => 9,
+            FieldSymbol::Weekday(Weekday::StandAlone) => 10,
+            FieldSymbol::DayPeriod(DayPeriod::AmPm) => 11,
+            FieldSymbol::DayPeriod(DayPeriod::NoonMidnight) => 12,
+            FieldSymbol::Hour(Hour::H11) => 13,
+            FieldSymbol::Hour(Hour::H12) => 14,
+            FieldSymbol::Hour(Hour::H23) => 15,
+            FieldSymbol::Hour(Hour::H24) => 16,
+            FieldSymbol::Minute => 17,
+            FieldSymbol::Second(Second::Second) => 18,
+            FieldSymbol::Second(Second::FractionalSecond) => 19,
+            FieldSymbol::Second(Second::Millisecond) => 20,
+        }
+    }
+}
+
 impl TryFrom<u8> for FieldSymbol {
     type Error = SymbolError;
     fn try_from(b: u8) -> Result<Self, Self::Error> {
@@ -52,7 +93,53 @@ impl TryFrom<char> for FieldSymbol {
     }
 }
 
+impl From<FieldSymbol> for char {
+    fn from(symbol: FieldSymbol) -> Self {
+        match symbol {
+            FieldSymbol::Year(year) => match year {
+                Year::Calendar => 'y',
+                Year::WeekOf => 'Y',
+            },
+            FieldSymbol::Month(month) => match month {
+                Month::Format => 'M',
+                Month::StandAlone => 'L',
+            },
+            FieldSymbol::Day(day) => match day {
+                Day::DayOfMonth => 'd',
+                Day::DayOfYear => 'D',
+                Day::DayOfWeekInMonth => 'F',
+                Day::ModifiedJulianDay => 'g',
+            },
+            FieldSymbol::Weekday(weekday) => match weekday {
+                Weekday::Format => 'E',
+                Weekday::Local => 'e',
+                Weekday::StandAlone => 'c',
+            },
+            FieldSymbol::DayPeriod(dayperiod) => match dayperiod {
+                DayPeriod::AmPm => 'a',
+                DayPeriod::NoonMidnight => 'b',
+            },
+            FieldSymbol::Hour(hour) => match hour {
+                Hour::H11 => 'K',
+                Hour::H12 => 'h',
+                Hour::H23 => 'H',
+                Hour::H24 => 'k',
+            },
+            FieldSymbol::Minute => 'm',
+            FieldSymbol::Second(second) => match second {
+                Second::Second => 's',
+                Second::FractionalSecond => 'S',
+                Second::Millisecond => 'A',
+            },
+        }
+    }
+}
+
 #[derive(Debug, PartialEq, Clone, Copy)]
+#[cfg_attr(
+    feature = "provider_serde",
+    derive(serde::Serialize, serde::Deserialize)
+)]
 pub enum Year {
     Calendar,
     WeekOf,
@@ -76,6 +163,10 @@ impl From<Year> for FieldSymbol {
 }
 
 #[derive(Debug, PartialEq, Clone, Copy)]
+#[cfg_attr(
+    feature = "provider_serde",
+    derive(serde::Serialize, serde::Deserialize)
+)]
 pub enum Month {
     Format,
     StandAlone,
@@ -99,6 +190,10 @@ impl From<Month> for FieldSymbol {
 }
 
 #[derive(Debug, PartialEq, Clone, Copy)]
+#[cfg_attr(
+    feature = "provider_serde",
+    derive(serde::Serialize, serde::Deserialize)
+)]
 pub enum Day {
     DayOfMonth,
     DayOfYear,
@@ -126,6 +221,10 @@ impl From<Day> for FieldSymbol {
 }
 
 #[derive(Debug, PartialEq, Clone, Copy)]
+#[cfg_attr(
+    feature = "provider_serde",
+    derive(serde::Serialize, serde::Deserialize)
+)]
 pub enum Hour {
     H11,
     H12,
@@ -153,6 +252,10 @@ impl From<Hour> for FieldSymbol {
 }
 
 #[derive(Debug, PartialEq, Clone, Copy)]
+#[cfg_attr(
+    feature = "provider_serde",
+    derive(serde::Serialize, serde::Deserialize)
+)]
 pub enum Second {
     Second,
     FractionalSecond,
@@ -178,6 +281,10 @@ impl From<Second> for FieldSymbol {
 }
 
 #[derive(Debug, PartialEq, Clone, Copy)]
+#[cfg_attr(
+    feature = "provider_serde",
+    derive(serde::Serialize, serde::Deserialize)
+)]
 pub enum Weekday {
     Format,
     Local,
@@ -203,6 +310,10 @@ impl From<Weekday> for FieldSymbol {
 }
 
 #[derive(Debug, PartialEq, Clone, Copy)]
+#[cfg_attr(
+    feature = "provider_serde",
+    derive(serde::Serialize, serde::Deserialize)
+)]
 pub enum DayPeriod {
     AmPm,
     NoonMidnight,