TraceGenerator trait (#663)

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crates/prover/Cargo.toml

@@ -10,6 +10,7 @@ blake2.workspace = true
 blake3.workspace = true
 bytemuck = { workspace = true, features = ["derive"] }
 cfg-if = "1.0.0"
+downcast-rs = "1.2"
 educe.workspace = true
 hex.workspace = true
 itertools.workspace = true

crates/prover/src/lib.rs

@@ -16,3 +16,4 @@ pub mod core;
 pub mod examples;
 pub mod hash_functions;
 pub mod math;
+pub mod trace_generation;

crates/prover/src/trace_generation/mod.rs

@@ -0,0 +1,36 @@
+use std::collections::HashMap;
+
+use downcast_rs::{impl_downcast, Downcast};
+
+use crate::core::backend::Backend;
+use crate::core::fields::m31::BaseField;
+use crate::core::poly::circle::CircleEvaluation;
+use crate::core::poly::BitReversedOrder;
+use crate::core::ColumnVec;
+
+pub trait ComponentGen: Downcast {}
+impl_downcast!(ComponentGen);
+
+pub struct ComponentRegistry {
+    _components: HashMap<String, Box<dyn ComponentGen>>,
+}
+
+// A trait to generate a a trace.
+// Generates the trace given a list of inputs collects inputs for subcomponents.
+pub trait TraceGenerator<B: Backend> {
+    type ComponentInputs;
+
+    /// Add inputs for the trace generation of the component.
+    /// This function should be called from the caller components before calling `write_trace` of
+    /// this component.
+    fn add_inputs(&mut self, inputs: &Self::ComponentInputs);
+
+    /// Allocates and returns the trace of the component and updates the
+    /// subcomponents with the corresponding inputs.
+    /// Should be called only after all the inputs are available.
+    // TODO(ShaharS): change `component_id` to a struct that contains the id and the component name.
+    fn write_trace(
+        component_id: &str,
+        registry: &mut ComponentRegistry,
+    ) -> ColumnVec<CircleEvaluation<B, BaseField, BitReversedOrder>>;
+}