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[Forpee]

This PR aims to address #331

• Ported bellpepper-core (& some parts of bellpepper) + Poseidon implementation from @argumentcomputer.

Remaining items:

There’s some unused code from the bellpepper and Poseidon port. Should we remove it now, or do you think it might be useful to keep for potential future needs?

[Forpee]

@microsoft-github-policy-service agree company="ICME"

[srinathsetty]

Hi @Forpee! thanks!

Yes, it is preferred to have a minimal implementation of the required methods. Please attribute the original source if they are taken from an existing library.

[srinathsetty]

For poseidon code, it seems like we are not using a bunch of code. For example, in src/lib.rs, replace pub mod provider with mod provider (this makes clippy complain about unused code). I get the following unused code. Can we please trim code to minimize unused code?

error: variants FullBuffer, IndexOutOfBounds, GpuError, and Other are never constructed
--> src/provider/poseidon/mod.rs:98:3
|
96 | pub enum PoseidonError {
| ------------- variants in this enum
97 | /// The allowed num...
98 | FullBuffer,
| ^^^^^^^^^^
99 | /// Attempt to reference an index element that is out of bounds
100 | IndexOutOfBounds,
| ^^^^^^^^^^^^^^^^
101 | /// GPU error
102 | GpuError(String),
| ^^^^^^^^
103 | /// Other error
104 | Other(String),
| ^^^^^
|
= note: PoseidonError has derived impls for the traits Clone and Debug, but these are intentionally ignored during dead code analysis
note: the lint level is defined here
--> src/lib.rs:4:3
|
4 | unused,
| ^^^^^^
= note: #[deny(dead_code)] implied by #[deny(unused)]

error: methods is_allocated and is_num are never used
--> src/provider/poseidon/circuit2.rs:31:16
|
29 | impl<Scalar: PrimeField> Elt {
| ------------------------------------ methods in this implementation
30 | /// Check if the Elt is allocated.
31 | pub const fn is_allocated(&self) -> bool {
| ^^^^^^^^^^^^
...
36 | pub const fn is_num(&self) -> bool {
| ^^^^^^

error: variants Correct and OptimizedDynamic are never constructed
--> src/provider/poseidon/poseidon_inner.rs:119:3
|
116 | pub enum HashMode {
| -------- variants in this enum
...
119 | Correct,
| ^^^^^^^
...
122 | OptimizedDynamic,
| ^^^^^^^^^^^^^^^^
|
= note: HashMode has derived impls for the traits Clone and Debug, but these are intentionally ignored during dead code analysis

error: associated items new_constant_length and with_length are never used
--> src/provider/poseidon/poseidon_inner.rs:150:10
|
130 | / impl<F, A> PoseidonConstants<F, A>
131 | | where
132 | | F: PrimeField,
133 | | A: Arity,
| |______________- associated items in this implementation
...
150 | pub fn new_constant_length(length: usize) -> Self {
| ^^^^^^^^^^^^^^^^^^^
...
157 | pub fn with_length(&self, length: usize) -> Self {
| ^^^^^^^^^^^

error: associated items new_with_preimage, set_preimage, reset, and input are never used
--> src/provider/poseidon/poseidon_inner.rs:298:10
|
268 | / impl<'a, F, A> Poseidon<'a, F, A>
269 | | where
270 | | F: PrimeField,
271 | | A: Arity,
| |______________- associated items in this implementation
...
298 | pub fn new_with_preimage(preimage: &[F], constants: &'a PoseidonConstan...
| ^^^^^^^^^^^^^^^^^
...
346 | pub fn set_preimage(&mut self, preimage: &[F]) {
| ^^^^^^^^^^^^
...
353 | pub fn reset(&mut self) {
| ^^^^^
...
368 | pub fn input(&mut self, element: F) -> Result<usize, PoseidonError> {
| ^^^^^

error: methods reset and is_squeeze are never used
--> src/provider/poseidon/sponge/api.rs:106:16
|
104 | impl SpongeOp {
| ------------- methods in this implementation
105 | /// Reset the SpongeOp
106 | pub const fn reset(&self) -> Self {
| ^^^^^
...
126 | pub const fn is_squeeze(&self) -> bool {
| ^^^^^^^^^^

error: variant Duplex is never constructed
--> src/provider/poseidon/sponge/vanilla.rs:38:3
|
34 | pub enum Mode {
| ---- variant in this enum
...
38 | Duplex,
| ^^^^^^
|
= note: Mode has a derived impl for the trait Clone, but this is intentionally ignored during dead code analysis

error: multiple associated items are never used
--> src/provider/poseidon/sponge/vanilla.rs:77:6
|
62 | pub trait SpongeTrait<'a, F: PrimeField, A: Arity>
| ----------- associated items in this trait
...
77 | fn simplex_constants(size: usize) -> PoseidonConstants<F, A> {
| ^^^^^^^^^^^^^^^^^
...
82 | fn duplex_constants() -> PoseidonConstants<F, A> {
| ^^^^^^^^^^^^^^^^
...
121 | fn make_elt(&self, val: F, acc: &mut Self::Acc) -> Self::Elt;
| ^^^^^^^^
...
147 | fn is_squeezing(&self) -> bool {
| ^^^^^^^^^^^^
...
192 | fn is_exhausted(&self) -> bool {
| ^^^^^^^^^^^^
...
333 | fn absorb_elements(
| ^^^^^^^^^^^^^^^
...
345 | fn squeeze_elements(&mut self, count: usize, acc: &mut Self::Acc) -> Vec<...
| ^^^^^^^^^^^^^^^^

[srinathsetty]

Nit: This method seems unimplemented. Is it worth cutting out unimplemented methods to keep the codebase simple?

[srinathsetty]

It seems like there are some places this actually gets used. Will look more.

[srinathsetty]

Do we use this method anywhere?

[Forpee]

Yes, most notably in the Poseidon sponge circuit's permute_state method.

this line:
src/provider/poseidon/sponge/circuit.rs#L127