support addition!

src/lib.rs

@@ -1,3 +1,5 @@
+mod ops;
+
 pub const M_BITS: u8 = 5;
 pub const E_BITS: u8 = 3;
 const E_CAP: u8 = 4;

src/ops.rs

@@ -0,0 +1,35 @@
+use super::*;
+
+impl std::ops::Add for F8 {
+	type Output = Self;
+
+	fn add(self, rhs: Self) -> Self::Output {
+		let (m1, e1) = self.split_unbias();
+		let (m2, e2) = rhs.split_unbias();
+		if e1 < e2 {
+			return rhs + self;
+		}
+		if rhs.0 == 0 {
+			return self;
+		}
+		let e_diff = e1 - e2;
+		let m = m1 + (m2 >> e_diff);
+		Self::merge_unbias(m, e1)
+	}
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+
+	#[test]
+	fn test_add() {
+		assert_eq!(F8::from(0b0011) + F8::from(0b0000), F8::from(0b0011));
+		assert_eq!(F8::from(0b0000) + F8::from(0b0111), F8::from(0b0111));
+		assert_eq!(F8::from(0b0011) + F8::from(0b0101), F8::from(0b1000));
+		assert_eq!(F8::from(0b0101) + F8::from(0b0011), F8::from(0b1000));
+		assert_eq!(F8::from(0b0011) + F8::from(0b0110), F8::from(0b1001));
+		assert_eq!(F8::from(0b0011) + F8::from(0b0111), F8::from(0b1010));
+		assert_eq!(F8::from(0b1100) + F8::from(0b0001), F8::from(0b1101));
+	}
+}