Add two different HostHook impls

Cargo.toml

@@ -102,10 +102,11 @@ zoneinfo64 = { workspace = true }
 resb = "0.1.0"
 
 [features]
-default = ["sys"]
+default = ["sys-local"]
 log = ["dep:log"]
 compiled_data = ["tzdb"]
-sys = ["std", "compiled_data", "dep:web-time", "dep:iana-time-zone"]
+sys = ["std", "compiled_data", "dep:web-time"]
+sys-local = ["sys", "dep:iana-time-zone"]
 tzdb = [
     "std",
     "timezone_provider/tzif",

src/builtins/core/now.rs

@@ -213,7 +213,7 @@ mod tests {
         assert_eq!(duration.milliseconds(), 0);
     }
 
-    #[cfg(all(feature = "tzdb", feature = "sys", feature = "compiled_data"))]
+    #[cfg(all(feature = "tzdb", feature = "sys-local", feature = "compiled_data"))]
     #[test]
     fn now_datetime_test() {
         use crate::Temporal;
@@ -222,9 +222,9 @@ mod tests {
 
         let sleep = 2;
 
-        let before = Temporal::now().plain_date_time_iso(None).unwrap();
+        let before = Temporal::local_now().plain_date_time_iso(None).unwrap();
         thread::sleep(StdDuration::from_secs(sleep));
-        let after = Temporal::now().plain_date_time_iso(None).unwrap();
+        let after = Temporal::local_now().plain_date_time_iso(None).unwrap();
 
         let diff = after.since(&before, DifferenceSettings::default()).unwrap();
 

src/lib.rs

@@ -111,8 +111,8 @@
 //! # #[cfg(all(feature = "sys", feature = "compiled_data"))] {
 //! use core::cmp::Ordering;
 //! use temporal_rs::{Temporal, Calendar, ZonedDateTime};
-//! let current_instant = Temporal::now().instant().unwrap();
-//! let current_zoned_date_time = Temporal::now().zoned_date_time_iso(None).unwrap();
+//! let current_instant = Temporal::utc_now().instant().unwrap();
+//! let current_zoned_date_time = Temporal::utc_now().zoned_date_time_iso(None).unwrap();
 //!
 //! /// Create a `ZonedDateTime` from the requested instant.
 //! let zoned_date_time_from_instant = ZonedDateTime::try_new(
@@ -279,7 +279,7 @@ pub mod primitive;
 pub mod provider;
 
 #[cfg(feature = "sys")]
-pub(crate) mod sys;
+pub mod sys;
 
 mod builtins;
 
@@ -306,7 +306,7 @@ pub use error::TemporalError;
 
 #[cfg(feature = "sys")]
 #[doc(inline)]
-pub use sys::{DefaultHostSystem, Temporal};
+pub use sys::Temporal;
 
 pub mod partial {
     //! Partial date and time component records

src/sys.rs

@@ -25,25 +25,76 @@ pub struct Temporal;
 
 impl Temporal {
     /// Get a `Now` object for the default host system.
-    pub const fn now() -> Now<DefaultHostSystem> {
-        Now::new(DefaultHostSystem)
+    #[cfg(feature = "sys-local")]
+    #[deprecated(
+        since = "0.1.0",
+        note = "`now` deprecated was not clear about the host system implementation, please use `local_now`"
+    )]
+    pub fn now() -> Now<LocalHostSystem> {
+        Now::new(LocalHostSystem)
+    }
+
+    /// Get a `Now` object with a [`LocalHostSystem`], which
+    /// will use the host system's time zone as a fallback.
+    #[cfg(feature = "sys-local")]
+    pub fn local_now() -> Now<LocalHostSystem> {
+        Now::new(LocalHostSystem)
+    }
+
+    /// Get a `Now` object with a [`UtcHostSystem`], which
+    /// will use a UTC time zone as a fallback.
+    #[cfg(feature = "sys")]
+    pub fn utc_now() -> Now<UtcHostSystem> {
+        Now::new(UtcHostSystem)
+    }
+}
+
+/// A UTC host system implementation that will return the current time
+/// with the a UTC time zone as fallback.
+///
+/// This implementation is backed by [`std::time::SystemTime`].
+#[cfg(feature = "sys")]
+pub struct UtcHostSystem;
+
+#[cfg(feature = "sys")]
+impl HostHooks for UtcHostSystem {}
+
+#[cfg(feature = "sys")]
+impl HostClock for UtcHostSystem {
+    fn get_host_epoch_nanoseconds(&self) -> TemporalResult<EpochNanoseconds> {
+        get_system_nanoseconds()
+    }
+}
+
+#[cfg(feature = "sys")]
+impl HostTimeZone for UtcHostSystem {
+    fn get_host_time_zone(
+        &self,
+        provider: &(impl TimeZoneProvider + ?Sized),
+    ) -> TemporalResult<TimeZone> {
+        Ok(TimeZone::utc_with_provider(provider))
     }
 }
 
-/// A default host system implementation
+/// A local host system implementation that will return the current time
+/// with the system time zone as a fallback.
 ///
-/// This implementation is backed by [`SystemTime`] and [`iana_time_zone`]
-pub struct DefaultHostSystem;
+/// This implementation is backed by [`std::time::SystemTime`] and [`iana_time_zone`]
+#[cfg(feature = "sys-local")]
+pub struct LocalHostSystem;
 
-impl HostHooks for DefaultHostSystem {}
+#[cfg(feature = "sys-local")]
+impl HostHooks for LocalHostSystem {}
 
-impl HostClock for DefaultHostSystem {
+#[cfg(feature = "sys-local")]
+impl HostClock for LocalHostSystem {
     fn get_host_epoch_nanoseconds(&self) -> TemporalResult<EpochNanoseconds> {
         get_system_nanoseconds()
     }
 }
 
-impl HostTimeZone for DefaultHostSystem {
+#[cfg(feature = "sys-local")]
+impl HostTimeZone for LocalHostSystem {
     fn get_host_time_zone(
         &self,
         provider: &(impl TimeZoneProvider + ?Sized),
@@ -52,6 +103,7 @@ impl HostTimeZone for DefaultHostSystem {
     }
 }
 
+#[cfg(feature = "sys-local")]
 #[inline]
 pub(crate) fn get_system_timezone(
     provider: &(impl TimeZoneProvider + ?Sized),