Group units, formatting, and statistics under quantity

src/quantity/units.rs

@@ -0,0 +1,56 @@
+//! This module contains common units.
+
+/// Supported time units
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum TimeUnit {
+    Second,
+    MilliSecond,
+    MicroSecond,
+    Minute,
+    Hour,
+}
+
+impl TimeUnit {
+    /// The abbreviation of the TimeUnit.
+    pub fn short_name(self) -> String {
+        match self {
+            TimeUnit::Second => String::from("s"),
+            TimeUnit::MilliSecond => String::from("ms"),
+            TimeUnit::MicroSecond => String::from("µs"),
+            TimeUnit::Minute => String::from("min"),
+            TimeUnit::Hour => String::from("h"),
+        }
+    }
+
+    /// Returns the value in seconds formatted for the TimeUnit.
+    pub fn format(self, value: f64) -> String {
+        match self {
+            TimeUnit::Second => format!("{value:.3}"),
+            TimeUnit::MilliSecond => format!("{:.1}", value * 1e3),
+            TimeUnit::MicroSecond => format!("{:.1}", value * 1e6),
+            TimeUnit::Minute => format!("{:.1}", value / 60.0),
+            TimeUnit::Hour => format!("{:.1}", value / 3600.0),
+        }
+    }
+}
+
+#[test]
+fn test_unit_short_name() {
+    assert_eq!("s", TimeUnit::Second.short_name());
+    assert_eq!("ms", TimeUnit::MilliSecond.short_name());
+    assert_eq!("µs", TimeUnit::MicroSecond.short_name());
+    assert_eq!("min", TimeUnit::Minute.short_name());
+    assert_eq!("h", TimeUnit::Hour.short_name());
+}
+
+// Note - the values are rounded when formatted.
+#[test]
+fn test_unit_format() {
+    let value: f64 = 123.456789;
+    assert_eq!("123.457", TimeUnit::Second.format(value));
+    assert_eq!("123456.8", TimeUnit::MilliSecond.format(value));
+
+    assert_eq!("1234.6", TimeUnit::MicroSecond.format(0.00123456));
+    assert_eq!("2.1", TimeUnit::Minute.format(value));
+    assert_eq!("0.0", TimeUnit::Hour.format(value));
+}