libdit: implement dit to timestamp conversion

libdit/src/lib.rs

@@ -3,6 +3,7 @@ pub mod libdit {
 	use std::str::FromStr;
 
 	/// Represents a time in a StarDIT day
+	#[derive(Debug, PartialEq)]
 	pub struct Dit {
 		pub deca: u16,
 		pub decim: u16,
@@ -49,6 +50,12 @@ pub mod libdit {
 		(unix - (12.0 * 3600.0)) % 86400.0 / 86400.0
 	}
 
+	/// Returns relative progress in the day, between 0 and 1 corresponding to `dit`
+	pub fn dit_struct_to_dit(dit: Dit) -> f64 {
+		((dit.deca as f32 / 10.0) + (dit.decim as f32 / 1000.0) + (dit.desec as f32 / 100000.0))
+			.into()
+	}
+
 	/// Returns a struct containing deca, decim and desec corresponding to `unix`
 	pub fn unix_to_dit_struct(unix: f64) -> Dit {
 		let dit = unix_to_dit(unix);
@@ -59,6 +66,11 @@ pub mod libdit {
 		}
 	}
 
+	/// Returns a unix timestamp corresponding to `dit`
+	pub fn dit_struct_to_unix(dit: Dit) -> f64 {
+		dit_struct_to_dit(dit) * 86400.0 + (12.0 * 3600.0)
+	}
+
 	/// Returns a string containing "deca.decim.desec" corresponding to `unix`
 	///
 	/// # Examples

libdit/tests/libdit.rs

@@ -1,4 +1,7 @@
+use libdit::libdit::dit_struct_to_unix;
 use libdit::libdit::unix_to_dit_string;
+use libdit::libdit::unix_to_dit_struct;
+use libdit::libdit::Dit;
 
 #[test]
 fn test_unix_to_dit_string() {
@@ -7,3 +10,27 @@ fn test_unix_to_dit_string() {
 	assert_eq!("9.99.99", unix_to_dit_string(1672574399.9999));
 	assert_eq!("0.00.00", unix_to_dit_string(1672574400.0000));
 }
+
+#[test]
+fn test_unix_to_dit_struct() {
+	assert_eq!(
+		Dit {
+			deca: 0,
+			decim: 0,
+			desec: 0
+		},
+		unix_to_dit_struct(43200.0)
+	);
+}
+
+#[test]
+fn test_dit_struct_to_unix() {
+	assert_eq!(
+		43200.0,
+		dit_struct_to_unix(Dit {
+			deca: 0,
+			decim: 0,
+			desec: 0
+		})
+	);
+}