Merge pull request #1371 from andyleiserson/repeat-n

Use repeat_n from std now that it is stable
private-attribution · Oct 25, 2024 · 482c15c · 482c15c
2 parents 47c3350 + ad8ea60
commit 482c15c
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Showing 6 changed files with 12 additions and 42 deletions.
diff --git a/ipa-core/Cargo.toml b/ipa-core/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "ipa-core"
 version = "0.1.0"
-rust-version = "1.80.0"
+rust-version = "1.82.0"
 edition = "2021"
 build = "build.rs"
 

diff --git a/ipa-core/src/helpers/mod.rs b/ipa-core/src/helpers/mod.rs
@@ -634,36 +634,6 @@ where
     }
 }
 
-pub struct RepeatN<T> {
-    element: T,
-    count: usize,
-}
-
-// As of Apr. 2024, this is unstable in `std::iter`. It is also available in `itertools`.
-// The advantage over `repeat(element).take(count)` that we care about is that this
-// implements `ExactSizeIterator`. The other advantage is that `repeat_n` can return
-// the original value (saving a clone) on the last iteration.
-pub fn repeat_n<T: Clone>(element: T, count: usize) -> RepeatN<T> {
-    RepeatN { element, count }
-}
-
-impl<T: Clone> Iterator for RepeatN<T> {
-    type Item = T;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        (self.count > 0).then(|| {
-            self.count -= 1;
-            self.element.clone()
-        })
-    }
-
-    fn size_hint(&self) -> (usize, Option<usize>) {
-        (self.count, Some(self.count))
-    }
-}
-
-impl<T: Clone> ExactSizeIterator for RepeatN<T> {}
-
 #[cfg(all(test, unit_test))]
 mod tests {
     use super::*;

diff --git a/ipa-core/src/protocol/ipa_prf/boolean_ops/addition_sequential.rs b/ipa-core/src/protocol/ipa_prf/boolean_ops/addition_sequential.rs
@@ -1,11 +1,10 @@
-use std::iter::repeat;
+use std::iter::{repeat, repeat_n};
 
 use ipa_step::StepNarrow;
 
 use crate::{
     error::Error,
     ff::boolean::Boolean,
-    helpers::repeat_n,
     protocol::{
         basics::{BooleanProtocols, SecureMul},
         boolean::{or::bool_or, NBitStep},

diff --git a/ipa-core/src/protocol/ipa_prf/boolean_ops/share_conversion_aby.rs b/ipa-core/src/protocol/ipa_prf/boolean_ops/share_conversion_aby.rs
@@ -367,7 +367,7 @@ where
 
 #[cfg(all(test, unit_test))]
 mod tests {
-    use std::iter::{self, repeat_with};
+    use std::iter::{self, repeat_n, repeat_with};
 
     use curve25519_dalek::Scalar;
     use futures::stream::TryStreamExt;
@@ -378,7 +378,7 @@ mod tests {
     use super::*;
     use crate::{
         ff::{boolean_array::BA64, Serializable},
-        helpers::{repeat_n, stream::process_slice_by_chunks},
+        helpers::stream::process_slice_by_chunks,
         protocol::{
             context::{dzkp_validator::DZKPValidator, UpgradableContext, TEST_DZKP_STEPS},
             ipa_prf::{CONV_CHUNK, CONV_PROOF_CHUNK, PRF_CHUNK},

diff --git a/ipa-core/src/protocol/ipa_prf/prf_sharding/feature_label_dot_product.rs b/ipa-core/src/protocol/ipa_prf/prf_sharding/feature_label_dot_product.rs
@@ -1,12 +1,15 @@
-use std::{convert::Infallible, iter::zip};
+use std::{
+    convert::Infallible,
+    iter::{repeat_n, zip},
+};
 
 use futures::stream;
 use futures_util::{future::try_join, stream::unfold, Stream, StreamExt};
 
 use crate::{
     error::{Error, LengthError, UnwrapInfallible},
     ff::{boolean::Boolean, boolean_array::BooleanArray, Field, U128Conversions},
-    helpers::{repeat_n, stream::TryFlattenItersExt, TotalRecords},
+    helpers::{stream::TryFlattenItersExt, TotalRecords},
     protocol::{
         basics::{SecureMul, ShareKnownValue},
         boolean::{and::bool_and_8_bit, or::or},

diff --git a/ipa-core/src/protocol/ipa_prf/prf_sharding/mod.rs b/ipa-core/src/protocol/ipa_prf/prf_sharding/mod.rs
@@ -1,7 +1,6 @@
 use std::{
     convert::Infallible,
-    iter,
-    iter::zip,
+    iter::{self, repeat_n, zip},
     num::NonZeroU32,
     ops::{Not, Range},
 };
@@ -20,7 +19,7 @@ use crate::{
         boolean_array::{BooleanArray, BA32, BA7},
         ArrayAccess, Field, U128Conversions,
     },
-    helpers::{repeat_n, stream::TryFlattenItersExt, TotalRecords},
+    helpers::{stream::TryFlattenItersExt, TotalRecords},
     protocol::{
         basics::{select, BooleanArrayMul, BooleanProtocols, Reveal, SecureMul, ShareKnownValue},
         boolean::{
@@ -877,7 +876,7 @@ where
 
 #[cfg(all(test, unit_test))]
 pub mod tests {
-    use std::num::NonZeroU32;
+    use std::{iter::repeat_n, num::NonZeroU32};
 
     use super::{AttributionOutputs, PrfShardedIpaInputRow};
     use crate::{
@@ -886,7 +885,6 @@ pub mod tests {
             boolean_array::{BooleanArray, BA16, BA20, BA3, BA5, BA8},
             Field, U128Conversions,
         },
-        helpers::repeat_n,
         protocol::ipa_prf::{
             oprf_padding::PaddingParameters, prf_sharding::attribute_cap_aggregate,
         },