WIP: Build out support for Now component

Cargo.toml

@@ -25,3 +25,4 @@ bitflags = "2.6.0"
 num-bigint = { version = "0.4.6", features = ["serde"] }
 num-traits = "0.2.19"
 ixdtf = { version = "0.2.0", features = ["duration"]}
+iana-time-zone = "0.1.60"

src/components/mod.rs

@@ -24,6 +24,7 @@ mod date;
 mod datetime;
 mod instant;
 mod month_day;
+mod now;
 mod time;
 mod year_month;
 mod zoneddatetime;
@@ -39,6 +40,8 @@ pub use instant::Instant;
 #[doc(inline)]
 pub use month_day::MonthDay;
 #[doc(inline)]
+pub use now::Now;
+#[doc(inline)]
 pub use time::Time;
 #[doc(inline)]
 pub use year_month::YearMonth;

src/components/now.rs

@@ -0,0 +1,28 @@
+//! The Temporal Now component
+
+use num_bigint::BigInt;
+use num_traits::FromPrimitive;
+
+use crate::{sys, TemporalResult, TemporalUnwrap};
+
+use super::Instant;
+
+/// The Temporal Now object.
+pub struct Now;
+
+impl Now {
+    /// Returns the current time zone.
+    pub fn time_zone_id() -> TemporalResult<String> {
+        sys::get_system_tz_identifier()
+    }
+
+    /// Returns the current instant
+    pub fn instant() -> TemporalResult<Instant> {
+        system_instant()
+    }
+}
+
+fn system_instant() -> TemporalResult<Instant> {
+    let nanos = sys::get_system_nanoseconds()?;
+    Instant::new(BigInt::from_u128(nanos).temporal_unwrap()?)
+}

src/lib.rs

@@ -50,6 +50,9 @@ pub(crate) mod rounding;
 #[doc(hidden)]
 pub(crate) mod utils;
 
+#[doc(hidden)]
+pub(crate) mod sys;
+
 // TODO: evaluate positives and negatives of using tinystr.
 // Re-exporting tinystr as a convenience, as it is currently tied into the API.
 pub use tinystr::TinyAsciiStr;

src/sys.rs

@@ -0,0 +1,16 @@
+
+use std::time::{SystemTime, UNIX_EPOCH};
+
+use crate::{TemporalError, TemporalResult};
+
+// TODO: Need to implement system handling for non_std.
+
+/// Returns the system time in nanoseconds.
+pub(crate) fn get_system_nanoseconds() -> TemporalResult<u128> {
+    SystemTime::now().duration_since(UNIX_EPOCH).map_err(|e| TemporalError::general(e.to_string())).map(|d| d.as_nanos())
+}
+
+/// Returns the system tz identifier
+pub(crate) fn get_system_tz_identifier() -> TemporalResult<String> {
+    iana_time_zone::get_timezone().map_err(|e| TemporalError::general(e.to_string()))
+}