add binary display

src/lib.rs

@@ -40,6 +40,21 @@ impl F8 {
 	}
 }
 
+impl std::fmt::Binary for F8 {
+	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+		if f.alternate() {
+			f.write_str("0b")?;
+		}
+		if self.0 == 0 {
+			f.write_str("0.00000p0")?;
+			return Ok(());
+		}
+		let (m, e) = self.split();
+		write!(f, "1.{m:05b}p{e}", e = e as i8 - E_BIAS as i8)?;
+		Ok(())
+	}
+}
+
 impl From<u8> for F8 {
 	fn from(v: u8) -> Self {
 		if v == 0 {
@@ -112,4 +127,18 @@ mod tests {
 			assert_eq!(f32::from(F8::from(k)), k as f32);
 		}
 	}
+
+	#[test]
+	fn test_display() {
+		fn fmt_split(m: u8, e: u8) -> String {
+			let v = F8::merge(m, e);
+			format!("{v:b}")
+		}
+		assert_eq!("0.00000p0", fmt_split(0, 0));
+		assert_eq!("1.00000p0", fmt_split(0, E_BIAS));
+		assert_eq!("1.00000p1", fmt_split(0, E_BIAS + 1));
+		assert_eq!("1.00000p-1", fmt_split(0, E_BIAS - 1));
+		assert_eq!("1.00001p0", fmt_split(1, E_BIAS));
+		assert_eq!("1.11111p0", fmt_split(0b11111, E_BIAS));
+	}
 }