From e642b8241040be03a834c75ef9d25dfb8a7866e2 Mon Sep 17 00:00:00 2001
From: Nicholas Ward <npward@berkeley.edu>
Date: Tue, 25 Apr 2023 17:26:37 -0700
Subject: [PATCH] move serialization to separate example

---
 plonky2/examples/fibonacci.rs               | 19 +-----
 plonky2/examples/fibonacci_serialization.rs | 69 +++++++++++++++++++++
 2 files changed, 70 insertions(+), 18 deletions(-)
 create mode 100644 plonky2/examples/fibonacci_serialization.rs

diff --git a/plonky2/examples/fibonacci.rs b/plonky2/examples/fibonacci.rs
index 459f4c9d..e3d865b9 100644
--- a/plonky2/examples/fibonacci.rs
+++ b/plonky2/examples/fibonacci.rs
@@ -1,7 +1,5 @@
 #![allow(clippy::upper_case_acronyms)]
 
-use std::fs;
-
 use anyhow::Result;
 use plonky2::field::types::Field;
 use plonky2::iop::witness::{PartialWitness, WitnessWrite};
@@ -41,24 +39,9 @@ fn main() -> Result<()> {
     pw.set_target(initial_a, F::ZERO);
     pw.set_target(initial_b, F::ONE);
 
-    let data = builder.build_without_randomizing::<C>();
-
-    let common_circuit_data_serialized = serde_json::to_string(&data.common).unwrap();
-    fs::write("common_circuit_data.json", common_circuit_data_serialized)
-        .expect("Unable to write file");
-
-    let verifier_only_circuit_data_serialized = serde_json::to_string(&data.verifier_only).unwrap();
-    fs::write(
-        "verifier_only_circuit_data.json",
-        verifier_only_circuit_data_serialized,
-    )
-    .expect("Unable to write file");
-
+    let data = builder.build::<C>();
     let proof = data.prove(pw)?;
 
-    let proof_serialized = serde_json::to_string(&proof).unwrap();
-    fs::write("proof_with_public_inputs.json", proof_serialized).expect("Unable to write file");
-
     println!(
         "100th Fibonacci number mod |F| (starting with {}, {}) is: {}",
         proof.public_inputs[0], proof.public_inputs[1], proof.public_inputs[2]
diff --git a/plonky2/examples/fibonacci_serialization.rs b/plonky2/examples/fibonacci_serialization.rs
new file mode 100644
index 00000000..a252884c
--- /dev/null
+++ b/plonky2/examples/fibonacci_serialization.rs
@@ -0,0 +1,69 @@
+#![allow(clippy::upper_case_acronyms)]
+
+use std::fs;
+
+use anyhow::Result;
+use plonky2::field::types::Field;
+use plonky2::iop::witness::{PartialWitness, WitnessWrite};
+use plonky2::plonk::circuit_builder::CircuitBuilder;
+use plonky2::plonk::circuit_data::CircuitConfig;
+use plonky2::plonk::config::{GenericConfig, PoseidonGoldilocksConfig};
+
+/// An example of using Plonky2 to prove a statement of the form
+/// "I know the 100th element of the Fibonacci sequence, starting with constants a and b."
+/// When a == 0 and b == 1, this is proving knowledge of the 100th (standard) Fibonacci number.
+/// This example also serializes the circuit data and proof to JSON files.
+fn main() -> Result<()> {
+    const D: usize = 2;
+    type C = PoseidonGoldilocksConfig;
+    type F = <C as GenericConfig<D>>::F;
+
+    let config = CircuitConfig::standard_recursion_config();
+    let mut builder = CircuitBuilder::<F, D>::new(config);
+
+    // The arithmetic circuit.
+    let initial_a = builder.add_virtual_target();
+    let initial_b = builder.add_virtual_target();
+    let mut prev_target = initial_a;
+    let mut cur_target = initial_b;
+    for _ in 0..99 {
+        let temp = builder.add(prev_target, cur_target);
+        prev_target = cur_target;
+        cur_target = temp;
+    }
+
+    // Public inputs are the two initial values (provided below) and the result (which is generated).
+    builder.register_public_input(initial_a);
+    builder.register_public_input(initial_b);
+    builder.register_public_input(cur_target);
+
+    // Provide initial values.
+    let mut pw = PartialWitness::new();
+    pw.set_target(initial_a, F::ZERO);
+    pw.set_target(initial_b, F::ONE);
+
+    let data = builder.build_without_randomizing::<C>();
+
+    let common_circuit_data_serialized = serde_json::to_string(&data.common).unwrap();
+    fs::write("common_circuit_data.json", common_circuit_data_serialized)
+        .expect("Unable to write file");
+
+    let verifier_only_circuit_data_serialized = serde_json::to_string(&data.verifier_only).unwrap();
+    fs::write(
+        "verifier_only_circuit_data.json",
+        verifier_only_circuit_data_serialized,
+    )
+    .expect("Unable to write file");
+
+    let proof = data.prove(pw)?;
+
+    let proof_serialized = serde_json::to_string(&proof).unwrap();
+    fs::write("proof_with_public_inputs.json", proof_serialized).expect("Unable to write file");
+
+    println!(
+        "100th Fibonacci number mod |F| (starting with {}, {}) is: {}",
+        proof.public_inputs[0], proof.public_inputs[1], proof.public_inputs[2]
+    );
+
+    data.verify(proof)
+}