chore: Add block-decoding example (#78)

examples/block-decode/src/main.rs

@@ -0,0 +1,35 @@
+use std::fmt::Debug;
+
+use net2::TcpStreamExt;
+
+use pallas::ledger::primitives::{alonzo, byron, probing, Era, Fragment};
+
+fn pretty_print(block: impl Debug) {
+    println!("{:?}", block)
+}
+
+fn main() {
+    let blocks = vec![
+        include_str!("blocks/byron.block"),
+        include_str!("blocks/shelley.block"),
+        include_str!("blocks/mary.block"),
+        include_str!("blocks/allegra.block"),
+        include_str!("blocks/alonzo.block"),
+    ];
+
+    for (idx, block_str) in blocks.iter().enumerate() {
+        let bytes = hex::decode(block_str).expect("valid hex");
+
+        match probing::probe_block_cbor_era(&bytes) {
+            probing::Outcome::Matched(era) => match era {
+                Era::Byron => pretty_print(byron::Block::decode_fragment(&bytes)),
+                // we use alonzo for everything post-shelly since it's backward compatible
+                Era::Shelley => pretty_print(alonzo::BlockWrapper::decode_fragment(&bytes)),
+                Era::Allegra => pretty_print(alonzo::BlockWrapper::decode_fragment(&bytes)),
+                Era::Mary => pretty_print(alonzo::BlockWrapper::decode_fragment(&bytes)),
+                Era::Alonzo => pretty_print(alonzo::BlockWrapper::decode_fragment(&bytes)),
+            },
+            _ => println!("couldn't infer block era"),
+        };
+    }
+}