Merge pull request #17 from asynchronics/feature/try_from

Add `try_from_*` methods, rename some `from_*`

README.md

@@ -85,7 +85,7 @@ let dt = clock.now().duration_since(t1);
 println!("Elapsed: {}s, {}ns", dt.as_secs(), dt.subsec_nanos());
 
 // Print out `t1` as a GPS timestamp.
-let gps_t1: GpsTime = t1.to_tai_time();
+let gps_t1: GpsTime = t1.to_tai_time().unwrap();
 println!("GPS timestamp: {}s, {}ns", gps_t1.as_secs(), gps_t1.subsec_nanos());
 ```
 
@@ -98,7 +98,7 @@ use tai_time::{MonotonicTime, Tai1958Time};
 // [±][Y]...[Y]YYYY-MM-DD hh:mm:ss[.d[d]...[d]]
 // or:
 // [±][Y]...[Y]YYYY-MM-DD'T'hh:mm:ss[.d[d]...[d]]
-let t0 = MonotonicTime::from_date_time(2222, 11, 11, 12, 34, 56, 789000000).unwrap();
+let t0 = MonotonicTime::try_from_date_time(2222, 11, 11, 12, 34, 56, 789000000).unwrap();
 assert_eq!("2222-11-11 12:34:56.789".parse(), Ok(t0));
 
 assert_eq!(

src/errors.rs

@@ -3,7 +3,8 @@
 use core::fmt;
 
 /// The error type returned when the result of a conversion to or from a
-/// [`TaiTime`](crate::TaiTime) is outside the representable range.
+/// [`TaiTime`](crate::TaiTime) is outside the representable range, or the
+/// conversion would cause the result to overflow.
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub struct OutOfRangeError(pub(crate) ());
@@ -53,7 +54,7 @@ impl fmt::Display for DateTimeError {
             Self::InvalidNanosecond(nanosec) => {
                 write!(fmt, "nanosecond value '{}' is not valid", nanosec)
             }
-            Self::OutOfRange => "timestamp out of representable range".fmt(fmt),
+            Self::OutOfRange => "timestamp outside representable range".fmt(fmt),
         }
     }
 }