allow creating CircomConfig from existing wasm instance

src/circom/builder.rs

@@ -7,7 +7,10 @@ use super::{CircomCircuit, R1CS};
 use num_bigint::BigInt;
 use std::collections::HashMap;
 
-use crate::{circom::R1CSFile, witness::WitnessCalculator};
+use crate::{
+    circom::R1CSFile,
+    witness::{Wasm, WitnessCalculator},
+};
 use color_eyre::Result;
 
 #[derive(Debug)]
@@ -38,6 +41,19 @@ impl<E: Pairing> CircomConfig<E> {
             sanity_check: false,
         })
     }
+
+    pub fn new_from_wasm(wasm: Wasm, r1cs: impl AsRef<Path>) -> Result<Self> {
+        let mut store = Store::default();
+        let wtns = WitnessCalculator::new_from_wasm(&mut store, wasm).unwrap();
+        let reader = File::open(r1cs)?;
+        let r1cs = R1CSFile::new(reader)?.into();
+        Ok(Self {
+            wtns,
+            r1cs,
+            store,
+            sanity_check: false,
+        })
+    }
 }
 
 impl<E: Pairing> CircomBuilder<E> {

src/witness/witness_calculator.rs

@@ -57,18 +57,14 @@ impl WitnessCalculator {
         Self::from_file(store, path)
     }
 
-    pub fn new_from_wasm(store: &mut Store, wasm: Wasm) -> Result<Self> {
-        Self::from_wasm(store, wasm)
-    }
-
     pub fn from_file(store: &mut Store, path: impl AsRef<std::path::Path>) -> Result<Self> {
         let module = Module::from_file(&store, path)?;
         Self::from_module(store, module)
     }
 
     pub fn from_module(store: &mut Store, module: Module) -> Result<Self> {
         let wasm = Self::make_wasm_runtime(store, module)?;
-        Self::from_wasm(store, wasm)
+        Self::new_from_wasm(store, wasm)
     }
 
     pub fn make_wasm_runtime(store: &mut Store, module: Module) -> Result<Wasm> {
@@ -99,7 +95,7 @@ impl WitnessCalculator {
         Ok(wasm)
     }
 
-    pub fn from_wasm(store: &mut Store, wasm: Wasm) -> Result<Self> {
+    pub fn new_from_wasm(store: &mut Store, wasm: Wasm) -> Result<Self> {
         let version = wasm.get_version(store).unwrap_or(1);
         // Circom 2 feature flag with version 2
         #[cfg(feature = "circom-2")]