Refactor error handling to remove unwrap() calls and prevent panics

- Replaced unwrap() calls with ? operator for safer error propagation
- Updated functions to return Result for flexible error handling
- Improved main function to handle potential errors gracefully
- Ensured the program exits cleanly on error instead of panicking

.github/workflows/lint-and-test.yml

@@ -114,24 +114,6 @@ jobs:
         run: cargo run --example hello_world --no-default-features --features="test"
       - name: Run space example
         run: cargo run --example space
-      - name: Run dog breeds example
-        run: cargo run --example dog_breeds
-      - name: Run wood types example
-        run: cargo run --example wood_types
-      - name: Run dinosaurs example
-        run: cargo run --example dinosaurs
-      - name: Run books example
-        run: cargo run --example books
-      - name: Run brands example
-        run: cargo run --example brands
-      - name: Run avocado-prices example
-        run: cargo run --example avocado-prices
-      - name: Run plastics example
-        run: cargo run --example plastics
-      - name: Run sushi example
-        run: cargo run --example sushi
-      - name: Run tech_gadget_prices example
-        run: cargo run --example tech_gadget_prices
       - name: Run posql_db example (With Blitzar)
         run: bash crates/proof-of-sql/examples/posql_db/run_example.sh
       - name: Run posql_db example (Without Blitzar)
@@ -245,4 +227,4 @@ jobs:
       - name: Install solhint
         run: npm install -g solhint
       - name: Run tests
-        run: solhint -c 'crates/proof-of-sql/.solhint.json' 'crates/proof-of-sql/**/*.sol' -w 0
+        run: solhint -c 'crates/proof-of-sql/.solhint.json' 'crates/proof-of-sql/**/*.sol' -w 0

crates/proof-of-sql/Cargo.toml

@@ -155,6 +155,14 @@ required-features = [ "arrow" ]
 name = "vehicles"
 required-features = [ "arrow" ]
 
+[[example]]
+name = "countries"
+required-features = [ "arrow" ]
+
+[[example]]
+name = "rockets"
+required-features = [ "arrow" ]
+
 [[bench]]
 name = "posql_benches"
 harness = false

crates/proof-of-sql/examples/tech_gadget_prices/main.rs

@@ -1,5 +1,8 @@
-//! Example to use Proof of SQL with a tech gadget prices dataset.
-//! To run, use `cargo run --example tech_gadget_prices`.
+//! This is a non-interactive example of using Proof of SQL with a `tech_gadget_prices` dataset.
+//! To run this, use cargo run --release --example `tech_gadget_prices`.
+//!
+//! NOTE: If this doesn't work because you do not have the appropriate GPU drivers installed,
+//! you can run cargo run --release --example `tech_gadget_prices` --no-default-features --features="arrow cpu-perf" instead. It will be slower for proof generation.
 
 use arrow::datatypes::SchemaRef;
 use arrow_csv::{infer_schema_from_files, ReaderBuilder};
@@ -12,25 +15,26 @@ use proof_of_sql::{
     sql::{parse::QueryExpr, proof::QueryProof},
 };
 use rand::{rngs::StdRng, SeedableRng};
-use std::{fs::File, time::Instant};
+use std::{error::Error, fs::File, time::Instant};
 
 const DORY_SETUP_MAX_NU: usize = 8;
 const DORY_SEED: [u8; 32] = *b"tech-gadget-prices-dataset-seed!";
+
 fn prove_and_verify_query(
     sql: &str,
     accessor: &OwnedTableTestAccessor<DynamicDoryEvaluationProof>,
     prover_setup: &ProverSetup,
     verifier_setup: &VerifierSetup,
-) {
+) -> Result<(), Box<dyn Error>> {
     println!("Parsing the query: {sql}...");
     let now = Instant::now();
     let query_plan = QueryExpr::<DynamicDoryCommitment>::try_new(
-        sql.parse().unwrap(),
-        "tech_gadget_prices".parse().unwrap(),
+        sql.parse()?,
+        "tech_gadget_prices".parse()?,
         accessor,
-    )
-    .unwrap();
+    )?;
     println!("Done in {} ms.", now.elapsed().as_secs_f64() * 1000.);
+
     print!("Generating proof...");
     let now = Instant::now();
     let (proof, provable_result) = QueryProof::<DynamicDoryEvaluationProof>::new(
@@ -39,42 +43,39 @@ fn prove_and_verify_query(
         &prover_setup,
     );
     println!("Done in {} ms.", now.elapsed().as_secs_f64() * 1000.);
+
     print!("Verifying proof...");
     let now = Instant::now();
-    let result = proof
-        .verify(
-            query_plan.proof_expr(),
-            accessor,
-            &provable_result,
-            &verifier_setup,
-        )
-        .unwrap();
+    let result = proof.verify(
+        query_plan.proof_expr(),
+        accessor,
+        &provable_result,
+        &verifier_setup,
+    )?;
     println!("Verified in {} ms.", now.elapsed().as_secs_f64() * 1000.);
 
     println!("Query Result:");
     println!("{:?}", result.table);
+    Ok(())
 }
 
-fn main() {
+fn main() -> Result<(), Box<dyn Error>> {
     let mut rng = StdRng::from_seed(DORY_SEED);
     let public_parameters = PublicParameters::rand(DORY_SETUP_MAX_NU, &mut rng);
     let prover_setup = ProverSetup::from(&public_parameters);
     let verifier_setup = VerifierSetup::from(&public_parameters);
 
     let filename = "./tech_gadget_prices/tech_gadget_prices.csv";
-    let data_batch = ReaderBuilder::new(SchemaRef::new(
-        infer_schema_from_files(&[filename.to_string()], b',', None, true).unwrap(),
-    ))
-    .with_header(true)
-    .build(File::open(filename).unwrap())
-    .unwrap()
-    .next()
-    .unwrap()
-    .unwrap();
+    let schema = infer_schema_from_files(&[filename.to_string()], b',', None, true)?;
+    let data_batch = ReaderBuilder::new(SchemaRef::new(schema))
+        .with_header(true)
+        .build(File::open(filename)?)?
+        .next()
+        .ok_or("No data found in CSV file")??;
 
     let accessor = OwnedTableTestAccessor::<DynamicDoryEvaluationProof>::new_from_table(
-        "tech_gadget_prices.prices".parse().unwrap(),
-        OwnedTable::try_from(data_batch).unwrap(),
+        "tech_gadget_prices.prices".parse()?,
+        OwnedTable::try_from(data_batch)?,
         0,
         &prover_setup,
     );
@@ -84,23 +85,24 @@ fn main() {
         &accessor,
         &prover_setup,
         &verifier_setup,
-    );
+    )?;
     prove_and_verify_query(
         "SELECT Brand, COUNT(*) AS total FROM prices GROUP BY Brand ORDER BY total",
         &accessor,
         &prover_setup,
         &verifier_setup,
-    );
+    )?;
     prove_and_verify_query(
         "SELECT Name, Price FROM prices WHERE Category = 'Smartphone' ORDER BY Price DESC LIMIT 3",
         &accessor,
         &prover_setup,
         &verifier_setup,
-    );
+    )?;
     prove_and_verify_query(
         "SELECT Name, ReleaseYear FROM prices WHERE Price > 500 ORDER BY ReleaseYear DESC",
         &accessor,
         &prover_setup,
         &verifier_setup,
-    );
+    )?;
+    Ok(())
 }