add an example to study the _recoding inbreeding_ phenomenon

this MR adds examples/inbreeding.rs which allows to do two things

• naive recoding: in order to generate a new random shard, we first k-decode the whole data and then 1-encode a single shard
• true recoding: to achieve the same goal, we directly k-recode shards into a new one

the scenario

regardless of the recoding strategy, the scenario is the same

1. data is split into k shards and n original shards are generated
2. for a given number of steps s, k shards are drawn randomly with replacement and we count the number of successful decoding, given a measure of the diversity, \delta = \frac{\#success}{\#attempts}
3. create a new recoded shard and add it to the n previous ones, i.e. n increases by one
4. repeat steps 2. and 3. as long as you want

results

examples/inbreeding.rs

@@ -223,6 +223,14 @@ struct Cli {
 fn main() {
     let cli = Cli::parse();
 
+    if cli.nb_measurements == 0 {
+        eprintln!(
+            "`--nb-measurements` should be a strictly positive integer, found {}",
+            cli.nb_measurements
+        );
+        exit(1);
+    }
+
     let mut rng = thread_rng();
 
     let bytes = random_bytes(cli.nb_bytes, &mut rng);