WIP

components/datetime/src/error.rs

@@ -71,6 +71,9 @@ pub enum DateTimeError {
     /// Missing time symbols
     #[displaydoc("Missing time symbols")]
     MissingTimeSymbols,
+    /// Missing symbols of a particular type
+    #[displaydoc("Missing symbols for {0}")]
+    MissingSymbols(&'static str),
     /// ordinal_rules must be set for PatternPlurals::MultipleVariants
     #[displaydoc("ordinal_rules must be set for PatternPlurals::MultipleVariants")]
     MissingOrdinalRules,

components/datetime/src/format/mod.rs

@@ -3,5 +3,6 @@
 // (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
 
 pub mod datetime;
+pub mod neo;
 pub mod time_zone;
 pub mod zoned_datetime;

components/datetime/src/format/neo.rs

@@ -0,0 +1,72 @@
+// 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 crate::calendar::CldrCalendar;
+use crate::error::DateTimeError as Error;
+use crate::fields;
+use crate::input;
+use crate::input::{DateTimeInput, LocalizedDateTimeInput};
+use crate::pattern::runtime::Pattern;
+use crate::provider::calendar::months;
+use crate::provider::date_time::DateSymbols;
+use crate::provider::neo::*;
+use core::fmt;
+use icu_calendar::types::Era;
+use icu_decimal::FixedDecimalFormatter;
+use icu_provider::prelude::*;
+use icu_calendar::types::MonthCode;
+
+pub struct DateTimePatternInterpolator<C: CldrCalendar> {
+    year_symbols: Option<DataPayload<C::YearSymbolsV1Marker>>,
+    month_symbols: Option<DataPayload<C::MonthSymbolsV1Marker>>,
+    weekday_symbols: Option<DataPayload<WeekdaySymbolsV1Marker>>,
+    dayperiod_symbols: Option<DataPayload<DayPeriodSymbolsV1Marker>>,
+    fixed_decimal_formatter: Option<FixedDecimalFormatter>,
+}
+
+struct ErasedDateTimePatternInterpolator {
+    year_symbols: Option<DataPayload<ErasedYearSymbolsV1Marker>>,
+    month_symbols: Option<DataPayload<ErasedMonthSymbolsV1Marker>>,
+    weekday_symbols: Option<DataPayload<WeekdaySymbolsV1Marker>>,
+    dayperiod_symbols: Option<DataPayload<DayPeriodSymbolsV1Marker>>,
+    fixed_decimal_formatter: Option<FixedDecimalFormatter>,
+}
+
+impl<'data> DateSymbols<'data> for ErasedDateTimePatternInterpolator {
+    fn get_symbol_for_month(
+        &self,
+        month: fields::Month,
+        length: fields::FieldLength,
+        code: MonthCode,
+    ) -> Result<(&str, bool), Error> {
+        todo!()
+    }
+
+    fn get_symbol_for_weekday(
+        &self,
+        weekday: fields::Weekday,
+        length: fields::FieldLength,
+        day: input::IsoWeekday,
+    ) -> Result<&str, Error> {
+        todo!()
+    }
+
+    fn get_symbol_for_era<'a>(&'a self, length: fields::FieldLength, era_code: &'a Era) -> &str {
+        todo!()
+    }
+}
+
+impl<C: CldrCalendar> DateTimePatternInterpolator<C> {
+    pub fn format_pattern<T, W>(
+        pattern: &Pattern,
+        datetime: &impl LocalizedDateTimeInput<T>,
+        writeable: &mut W,
+    ) -> Result<(), Error>
+    where
+        T: DateTimeInput,
+        W: fmt::Write + ?Sized,
+    {
+        unimplemented!()
+    }
+}

components/datetime/src/provider/neo.rs

@@ -3,6 +3,7 @@
 // (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
 
 mod adapter;
+mod impls;
 
 use crate::pattern::runtime;
 use icu_provider::prelude::*;
@@ -242,3 +243,13 @@ pub struct DateTimePatternV1<'data> {
     #[cfg_attr(feature = "serde", serde(borrow))]
     pub pattern: runtime::GenericPattern<'data>,
 }
+
+pub(crate) struct ErasedYearSymbolsV1Marker;
+impl DataMarker for ErasedYearSymbolsV1Marker {
+    type Yokeable = YearSymbolsV1<'static>;
+}
+
+pub(crate) struct ErasedMonthSymbolsV1Marker;
+impl DataMarker for ErasedMonthSymbolsV1Marker {
+    type Yokeable = MonthSymbolsV1<'static>;
+}

components/datetime/src/provider/neo/impls.rs

@@ -0,0 +1,3 @@
+// 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 ).