Add temporary hash function.

src/hash.rs

@@ -0,0 +1,57 @@
+//! Temporary hash function
+
+const fn hash_recursive<'a>(state: &mut [u8; 4], input: &'a [u8]) {
+    match input.len() {
+        3 => {
+            state[0] ^= input[0];
+            state[1] ^= input[1];
+            state[2] ^= input[2];
+        }
+        2 => {
+            state[0] ^= input[0];
+            state[1] ^= input[1];
+        }
+        1 => {
+            state[0] ^= input[0];
+        }
+        0 => {}
+        _ => {
+            state[0] ^= input[0];
+            state[1] ^= input[1];
+            state[2] ^= input[2];
+            state[3] ^= input[3];
+
+            // Mess with the state quite a bit
+            state[0] = u8::reverse_bits(state[0]) ^ state[2];
+            state[2] = state[0].wrapping_add(state[2]).wrapping_add(state[3]) ^ state[0];
+            state[3] = state[2].wrapping_add(state[3] << 2) ^ state[1];
+            state[1] = state[3] ^ 0xa3;
+
+            hash_recursive(state, &input[1..]);
+        }
+    }
+}
+
+pub const fn hash(input: &'static str) -> u32 {
+    let mut data = [0xDE, 0xED, 0xBE, 0xEF];
+    hash_recursive(&mut data, input.as_bytes());
+
+    // throw the data back into itself because why not
+    let input2 = [
+        u8::reverse_bits(data[1]),
+        data[2],
+        data[2],
+        data[1],
+        u8::reverse_bits(data[0]),
+        data[2],
+        u8::reverse_bits(data[3]),
+        u8::reverse_bits(data[2]),
+        data[3],
+        u8::reverse_bits(data[3]),
+        u8::reverse_bits(data[2]),
+        data[0],
+    ];
+    hash_recursive(&mut data, &input2);
+
+    u32::from_be_bytes(data)
+}