Suppress conflicting datetime fields in datagen (#6477)

Fixes #6205

Author: sffc

components/datetime/src/pattern/mod.rs

@@ -15,7 +15,7 @@ mod names;
 #[allow(clippy::module_inception)] // the file pattern.rs should contain DateTimePattern
 mod pattern;
 
-use crate::error::ErrorField;
+pub use crate::error::ErrorField;
 pub use formatter::DateTimePatternFormatter;
 pub use formatter::FormattedDateTimePattern;
 use icu_pattern::SinglePlaceholderPattern;

components/datetime/src/pattern/pattern.rs

@@ -115,11 +115,6 @@ impl DateTimePattern {
         Ok(Self { pattern })
     }
 
-    #[doc(hidden)] // TODO(#4467): Internal API
-    pub fn from_runtime_pattern(pattern: runtime::Pattern<'static>) -> Self {
-        Self { pattern }
-    }
-
     pub(crate) fn iter_items(&self) -> impl Iterator<Item = PatternItem> + '_ {
         self.pattern.items.iter()
     }
@@ -129,6 +124,28 @@ impl DateTimePattern {
     }
 }
 
+impl<'a> From<runtime::Pattern<'a>> for DateTimePattern {
+    fn from(pattern: runtime::Pattern<'a>) -> Self {
+        Self {
+            pattern: pattern.into_owned(),
+        }
+    }
+}
+
+impl<'a> From<runtime::PatternBorrowed<'a>> for DateTimePattern {
+    fn from(pattern: runtime::PatternBorrowed<'a>) -> Self {
+        Self {
+            pattern: pattern.as_pattern().into_owned(),
+        }
+    }
+}
+
+impl From<DateTimePattern> for runtime::Pattern<'_> {
+    fn from(value: DateTimePattern) -> Self {
+        value.pattern
+    }
+}
+
 impl FromStr for DateTimePattern {
     type Err = PatternError;
     fn from_str(s: &str) -> Result<Self, Self::Err> {

components/datetime/src/provider/fields/mod.rs

@@ -12,6 +12,7 @@ pub(crate) mod symbols;
 use displaydoc::Display;
 pub use length::{FieldLength, FieldNumericOverrides, LengthError};
 pub use symbols::*;
+use writeable::Writeable;
 
 #[cfg(any(feature = "experimental", feature = "datagen"))]
 pub mod components;
@@ -77,6 +78,21 @@ impl Field {
     }
 }
 
+impl Writeable for Field {
+    fn write_to<W: core::fmt::Write + ?Sized>(&self, sink: &mut W) -> core::fmt::Result {
+        let ch: char = self.symbol.into();
+        for _ in 0..self.length.to_len() {
+            sink.write_char(ch)?;
+        }
+        Ok(())
+    }
+    fn writeable_length_hint(&self) -> writeable::LengthHint {
+        writeable::LengthHint::exact(self.length.to_len())
+    }
+}
+
+writeable::impl_display_with_writeable!(Field);
+
 impl FieldULE {
     #[inline]
     pub(crate) fn validate_byte_pair(bytes: (u8, u8)) -> Result<(), zerovec::ule::UleError> {

components/datetime/src/provider/pattern/runtime/display.rs

@@ -77,10 +77,7 @@ impl Writeable for Pattern<'_> {
                 PatternItem::Field(field) => {
                     dump_buffer_into_formatter(&buffer, formatter)?;
                     buffer.clear();
-                    let ch: char = field.symbol.into();
-                    for _ in 0..field.length.to_len() {
-                        formatter.write_char(ch)?;
-                    }
+                    field.write_to(formatter)?;
                     if let FieldSymbol::DecimalSecond(decimal_second) = field.symbol {
                         formatter.write_char('.')?;
                         for _ in 0..(decimal_second as u8) {

components/datetime/src/provider/pattern/runtime/pattern.rs

@@ -116,7 +116,6 @@ impl Default for PatternMetadata {
 }
 
 impl Pattern<'_> {
-    #[cfg(feature = "datagen")]
     pub(crate) fn into_owned(self) -> Pattern<'static> {
         Pattern {
             items: self.items.into_owned(),

components/datetime/src/provider/skeleton/helpers.rs

@@ -114,6 +114,10 @@ impl SkeletonQuality {
     pub fn best() -> SkeletonQuality {
         SkeletonQuality(0)
     }
+    /// Returns whether this is an "excellent" match by an arbitrary definition.
+    pub fn is_excellent_match(self) -> bool {
+        self.0 < GLUE_DISTANCE
+    }
 }
 
 /// This function swaps out the time zone name field for the appropriate one. Skeleton matching

components/datetime/src/raw/neo.rs

@@ -734,7 +734,7 @@ impl<'a> DateTimeZonePatternDataBorrowed<'a> {
 
     pub(crate) fn to_pattern(self) -> DateTimePattern {
         let pattern = self.iter_items().collect::<runtime::Pattern>();
-        DateTimePattern::from_runtime_pattern(pattern)
+        DateTimePattern::from(pattern)
     }
 }
 

components/decimal/src/provider.rs

@@ -296,9 +296,9 @@ impl DecimalSymbols<'_> {
 }
 
 impl DecimalSymbols<'static> {
-    #[cfg(test)]
     /// Create a new en-US format for use in testing
-    pub(crate) fn new_en_for_testing() -> Self {
+    #[cfg(feature = "datagen")]
+    pub fn new_en_for_testing() -> Self {
         let strings = DecimalSymbolStrsBuilder {
             minus_sign_prefix: VarZeroCow::new_borrowed("-"),
             minus_sign_suffix: VarZeroCow::new_borrowed(""),