feat: render dot string to svg

zk_prover/Cargo.toml

@@ -13,6 +13,7 @@ dev-graph = ["halo2_proofs/dev-graph", "plotters"]
 halo2_proofs = { git = "https://github.com/summa-dev/halo2"}
 halo2_gadgets = { git = "https://github.com/summa-dev/halo2"}
 plotters = { version = "0.3.4", optional = true }
+graphviz-rust = {version = "0.7.1", optional = true}
 rand = "0.8"
 ark-std = { version = "0.3.0", features = ["print-trace"] }
 tabbycat = { version = "0.1", features = ["attributes"], optional = true }

zk_prover/src/chips/range/tests.rs

@@ -298,6 +298,13 @@ mod testing {
     fn print_range_check_dot_graph() {
         use std::io::Write;
 
+        use graphviz_rust::{
+            cmd::{CommandArg, Format},
+            dot_structures::*,
+            exec, parse,
+            printer::PrinterContext,
+        };
+
         let circuit = TestCircuit::<4> {
             a: Fp::from(0x1f2f3f4f),
             b: Fp::from(1),
@@ -308,5 +315,19 @@ mod testing {
         dot_graph.write_all(dot_string.as_bytes()).unwrap();
 
         print!("{}", dot_string);
+
+        // * Following svg generation requires graphviz client to be installed: https://graphviz.org/download/#executable-packages
+        // * Might be easier to use Graphviz Interactive Preview extension in VSCode to open the .dot file
+        // * https://marketplace.visualstudio.com/items?itemName=tintinweb.graphviz-interactive-preview
+        let g: Graph = parse(&dot_string).unwrap();
+        exec(
+            g,
+            &mut PrinterContext::default(),
+            vec![
+                Format::Svg.into(),
+                CommandArg::Output("prints/range-check-dot-graph.svg".to_string()),
+            ],
+        )
+        .unwrap();
     }
 }