fix: do a first round of a core replacement

Signed-off-by: Brandon H. Gomes <bhgomes@pm.me>

plonky2/examples/bench_recursion.rs

@@ -5,7 +5,7 @@
 #![allow(incomplete_features)]
 #![feature(generic_const_exprs)]
 
-use std::{num::ParseIntError, ops::RangeInclusive, str::FromStr};
+use core::{num::ParseIntError, ops::RangeInclusive, str::FromStr};
 
 use anyhow::{anyhow, Context as _, Result};
 use log::{info, Level, LevelFilter};

plonky2/examples/square_root.rs

@@ -1,4 +1,4 @@
-use std::marker::PhantomData;
+use core::marker::PhantomData;
 
 use anyhow::Result;
 use plonky2::field::types::{Field, PrimeField};

plonky2/src/fri/structure.rs

@@ -1,7 +1,7 @@
 //! Information about the structure of a FRI instance, in terms of the oracles and polynomials
 //! involved, and the points they are opened at.
 
-use std::ops::Range;
+use core::ops::Range;
 
 use crate::field::extension::Extendable;
 use crate::hash::hash_types::RichField;

plonky2/src/gadgets/arithmetic.rs

@@ -1,4 +1,4 @@
-use std::borrow::Borrow;
+use core::borrow::Borrow;
 
 use plonky2_field::extension::Extendable;
 use plonky2_field::types::Field64;

plonky2/src/gadgets/arithmetic_extension.rs

@@ -1,4 +1,4 @@
-use std::borrow::Borrow;
+use core::borrow::Borrow;
 
 use plonky2_field::extension::FieldExtension;
 use plonky2_field::extension::{Extendable, OEF};

plonky2/src/gadgets/split_base.rs

@@ -1,4 +1,4 @@
-use std::borrow::Borrow;
+use core::borrow::Borrow;
 
 use itertools::Itertools;
 use plonky2_field::extension::Extendable;

plonky2/src/gates/arithmetic_extension.rs

@@ -1,4 +1,4 @@
-use std::ops::Range;
+use core::ops::Range;
 
 use plonky2_field::extension::Extendable;
 use plonky2_field::extension::FieldExtension;

plonky2/src/gates/base_sum.rs

@@ -1,4 +1,4 @@
-use std::ops::Range;
+use core::ops::Range;
 
 use plonky2_field::extension::Extendable;
 use plonky2_field::packed::PackedField;

plonky2/src/gates/exponentiation.rs

@@ -1,4 +1,4 @@
-use std::marker::PhantomData;
+use core::marker::PhantomData;
 
 use plonky2_field::extension::Extendable;
 use plonky2_field::ops::Square;
@@ -282,7 +282,7 @@ impl<F: RichField + Extendable<D>, const D: usize> SimpleGenerator<F>
 
 #[cfg(test)]
 mod tests {
-    use std::marker::PhantomData;
+    use core::marker::PhantomData;
 
     use anyhow::Result;
     use plonky2_field::goldilocks_field::GoldilocksField;

plonky2/src/gates/gate.rs

@@ -1,7 +1,7 @@
+use core::fmt::{Debug, Error, Formatter};
+use core::hash::{Hash, Hasher};
+use core::ops::Range;
 use std::collections::HashMap;
-use std::fmt::{Debug, Error, Formatter};
-use std::hash::{Hash, Hasher};
-use std::ops::Range;
 use std::sync::Arc;
 
 use plonky2_field::batch_util::batch_multiply_inplace;

plonky2/src/gates/high_degree_interpolation.rs

@@ -1,5 +1,5 @@
-use std::marker::PhantomData;
-use std::ops::Range;
+use core::marker::PhantomData;
+use core::ops::Range;
 
 use plonky2_field::extension::algebra::PolynomialCoeffsAlgebra;
 use plonky2_field::extension::{Extendable, FieldExtension};
@@ -270,7 +270,7 @@ impl<F: RichField + Extendable<D>, const D: usize> SimpleGenerator<F>
 
 #[cfg(test)]
 mod tests {
-    use std::marker::PhantomData;
+    use core::marker::PhantomData;
 
     use anyhow::Result;
     use plonky2_field::goldilocks_field::GoldilocksField;

plonky2/src/gates/interpolation.rs

@@ -1,4 +1,4 @@
-use std::ops::Range;
+use core::ops::Range;
 
 use plonky2_field::extension::Extendable;
 

plonky2/src/gates/low_degree_interpolation.rs

@@ -1,5 +1,5 @@
-use std::marker::PhantomData;
-use std::ops::Range;
+use core::marker::PhantomData;
+use core::ops::Range;
 
 use plonky2_field::extension::algebra::PolynomialCoeffsAlgebra;
 use plonky2_field::extension::{Extendable, FieldExtension};

plonky2/src/gates/multiplication_extension.rs

@@ -1,4 +1,4 @@
-use std::ops::Range;
+use core::ops::Range;
 
 use plonky2_field::extension::Extendable;
 use plonky2_field::extension::FieldExtension;

plonky2/src/gates/poseidon.rs

@@ -1,4 +1,4 @@
-use std::marker::PhantomData;
+use core::marker::PhantomData;
 
 use plonky2_field::extension::Extendable;
 use plonky2_field::types::Field;

plonky2/src/gates/poseidon_mds.rs

@@ -1,5 +1,5 @@
-use std::marker::PhantomData;
-use std::ops::Range;
+use core::marker::PhantomData;
+use core::ops::Range;
 
 use plonky2_field::extension::algebra::ExtensionAlgebra;
 use plonky2_field::extension::Extendable;

plonky2/src/gates/public_input.rs

@@ -1,4 +1,4 @@
-use std::ops::Range;
+use core::ops::Range;
 
 use plonky2_field::extension::Extendable;
 use plonky2_field::packed::PackedField;

plonky2/src/gates/random_access.rs

@@ -1,4 +1,4 @@
-use std::marker::PhantomData;
+use core::marker::PhantomData;
 
 use itertools::Itertools;
 use plonky2_field::extension::Extendable;
@@ -376,7 +376,7 @@ impl<F: RichField + Extendable<D>, const D: usize> SimpleGenerator<F>
 
 #[cfg(test)]
 mod tests {
-    use std::marker::PhantomData;
+    use core::marker::PhantomData;
 
     use anyhow::Result;
     use plonky2_field::goldilocks_field::GoldilocksField;

plonky2/src/gates/reducing.rs

@@ -1,4 +1,4 @@
-use std::ops::Range;
+use core::ops::Range;
 
 use plonky2_field::extension::Extendable;
 use plonky2_field::extension::FieldExtension;

plonky2/src/gates/reducing_extension.rs

@@ -1,4 +1,4 @@
-use std::ops::Range;
+use core::ops::Range;
 
 use plonky2_field::extension::Extendable;
 use plonky2_field::extension::FieldExtension;

plonky2/src/gates/selectors.rs

@@ -1,4 +1,4 @@
-use std::ops::Range;
+use core::ops::Range;
 
 use plonky2_field::extension::Extendable;
 use plonky2_field::polynomial::PolynomialValues;

plonky2/src/gates/util.rs

@@ -1,4 +1,4 @@
-use std::marker::PhantomData;
+use core::marker::PhantomData;
 
 use plonky2_field::packed::PackedField;
 

plonky2/src/hash/hash_types.rs

@@ -36,7 +36,7 @@ impl<F: Field> HashOut<F> {
         Self { elements }
     }
 
-    #[cfg(feature = "parallel")]
+    #[cfg(all(feature = "parallel", feature = "rand"))]
     pub fn rand_from_rng<R: rand::Rng>(rng: &mut R) -> Self {
         Self {
             elements: [

plonky2/src/hash/keccak.rs

@@ -1,5 +1,5 @@
-use std::iter;
-use std::mem::size_of;
+use core::iter;
+use core::mem::size_of;
 
 use itertools::Itertools;
 use keccak_hash::keccak;

plonky2/src/hash/merkle_tree.rs

@@ -1,5 +1,5 @@
-use std::mem::MaybeUninit;
-use std::slice;
+use core::mem::MaybeUninit;
+use core::slice;
 
 use maybe_rayon::*;
 use plonky2_util::log2_strict;

plonky2/src/iop/challenger.rs

@@ -1,5 +1,5 @@
-use std::convert::TryInto;
-use std::marker::PhantomData;
+use core::convert::TryInto;
+use core::marker::PhantomData;
 
 use plonky2_field::extension::{Extendable, FieldExtension};
 

plonky2/src/iop/ext_target.rs

@@ -1,4 +1,4 @@
-use std::ops::Range;
+use core::ops::Range;
 
 use plonky2_field::extension::algebra::ExtensionAlgebra;
 use plonky2_field::extension::{Extendable, FieldExtension, OEF};

plonky2/src/iop/generator.rs

@@ -1,5 +1,5 @@
-use std::fmt::Debug;
-use std::marker::PhantomData;
+use core::fmt::Debug;
+use core::marker::PhantomData;
 
 use plonky2_field::extension::{Extendable, FieldExtension};
 use plonky2_field::types::Field;

plonky2/src/iop/target.rs

@@ -1,4 +1,4 @@
-use std::ops::Range;
+use core::ops::Range;
 
 use crate::iop::ext_target::ExtensionTarget;
 use crate::iop::wire::Wire;

plonky2/src/iop/wire.rs

@@ -1,4 +1,4 @@
-use std::ops::Range;
+use core::ops::Range;
 
 use crate::plonk::circuit_data::CircuitConfig;
 

plonky2/src/plonk/circuit_builder.rs

@@ -1,4 +1,4 @@
-use std::cmp::max;
+use core::cmp::max;
 use std::collections::{BTreeMap, HashMap, HashSet};
 use std::time::Instant;
 

plonky2/src/plonk/circuit_data.rs

@@ -1,5 +1,5 @@
+use core::ops::{Range, RangeFrom};
 use std::collections::BTreeMap;
-use std::ops::{Range, RangeFrom};
 
 use anyhow::Result;
 use plonky2_field::extension::Extendable;

plonky2/src/plonk/config.rs

@@ -1,4 +1,4 @@
-use std::fmt::Debug;
+use core::fmt::Debug;
 
 use plonky2_field::extension::quadratic::QuadraticExtension;
 use plonky2_field::extension::{Extendable, FieldExtension};

plonky2/src/plonk/prover.rs

@@ -1,4 +1,4 @@
-use std::mem::swap;
+use core::mem::swap;
 
 use anyhow::ensure;
 use anyhow::Result;
@@ -351,7 +351,7 @@ fn compute_quotient_polys<
     let num_batches = ceil_div_usize(points.len(), BATCH_SIZE);
     let quotient_values: Vec<Vec<F>> = points_batches
         .enumerate()
-        .map(|(batch_i, xs_batch)| {
+        .flat_map(|(batch_i, xs_batch)| {
             // Each batch must be the same size, except the last one, which may be smaller.
             debug_assert!(
                 xs_batch.len() == BATCH_SIZE
@@ -448,7 +448,6 @@ fn compute_quotient_polys<
             }
             quotient_values_batch
         })
-        .flatten()
         .collect();
 
     transpose(&quotient_values)

plonky2/src/plonk/vars.rs

@@ -1,4 +1,4 @@
-use std::ops::Range;
+use core::ops::Range;
 
 use plonky2_field::extension::algebra::ExtensionAlgebra;
 use plonky2_field::extension::{Extendable, FieldExtension};

plonky2/src/util/partial_products.rs

@@ -1,4 +1,4 @@
-use std::iter;
+use core::iter;
 
 use itertools::Itertools;
 use plonky2_field::extension::Extendable;

plonky2/src/util/reducing.rs

@@ -1,4 +1,4 @@
-use std::borrow::Borrow;
+use core::borrow::Borrow;
 
 use plonky2_field::extension::{Extendable, FieldExtension};
 use plonky2_field::packed::PackedField;

plonky2/src/util/strided_view.rs

@@ -1,6 +1,6 @@
-use std::marker::PhantomData;
-use std::mem::size_of;
-use std::ops::{Index, Range, RangeFrom, RangeFull, RangeInclusive, RangeTo, RangeToInclusive};
+use core::marker::PhantomData;
+use core::mem::size_of;
+use core::ops::{Index, Range, RangeFrom, RangeFull, RangeInclusive, RangeTo, RangeToInclusive};
 
 use plonky2_field::packed::PackedField;