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// Copyright 2020 IOTA Stiftung // // Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with // the License. You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on // an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and limitations under the License. //! A general-purpose ternary manipulation, translation and encoding crate. //! //! # Features //! //! - Creation of trit and tryte buffers with multiple encodings //! - Safe encoding API that allows the efficient manipulation and sharing of trit and tryte buffers and slices //! - Mutation of trit buffers and slices //! - Ternary BigInt implementation //! - Balanced and unbalanced ternary //! - `serde` support //! //! # Encodings //! //! This crate includes support for many different trit encodings. Encodings allow the trading off //! of different features against each other. //! //! [`T1B1`] is the canonical default encoding and represents every trit with a single byte of //! memory. It is the fastest encoding to manipulate since no bitwise operations are necessary to //! pack and unpack it from memory during manipulation. As a result of this, it also permits //! certain extra features like mutable chunking and accessing its contents through ordinary //! slices. //! //! [`T3B1`] is also commonly used. It provides good compression and has the advantage that it has //! an identical bit representation as a [`Tryte`] slice. For this reason, it is the only encoding //! that can be converted to a tryte slice with no overhead. //! //! [`T5B1`] is the most compressed encoding. It provides very high storage densities (almost //! optimal, in fact) and is the densest encoding supported by this crate. //! //! It is likely that one of the 3 encodings above will suit your requirements. In addition, this //! crate also supports [`T2B1`] and [`T4B1`] for completeness. //! //! # Byte Alignment //! //! This crate supports creating sub-slices of trit slices. To enable this, it stores extra //! metadata along with a trit slice in order to correct identify the index of a buffer it starts //! on. With compressed encodings, such as [`T3B1`], that starting index (and, indeed, the end //! index) may not fall exactly on a byte boundary. //! //! This crate makes a best attempt at avoiding the negative ramifications of this fact, but sadly //! some still leak through into the API. For example, some methods may panic if a slice does not //! have a byte-aligned starting index or otherwise does not fulfil certain invariants. However, //! all panicking behaviours are documented on each method such that you can easily avoid //! circumstances like this. //! //! When the documentation refers to 'byte alignment', it is referring specifically to whether the //! starting index is a multiple of the compression factor. For example a byte-aligned [`T3B1`] //! buffer will always start on an index of the *original* buffer that is a multiple of 3. #![deny(missing_docs)] use std::slice; /// Conversions between to and from standard types. pub mod convert; /// Types and traits that allow the implementation of new encoding formats. pub mod raw; /// The [`T1B1`] and [`T1B1Buf`] encodings. pub mod t1b1; /// The [`T2B1`] and [`T2B1Buf`] encodings. pub mod t2b1; /// The [`T3B1`] and [`T3B1Buf`] encodings. pub mod t3b1; /// The [`T4B1`] and [`T4B1Buf`] encodings. pub mod t4b1; /// The [`T5B1`] and [`T5B1Buf`] encodings. pub mod t5b1; /// Types and traits used to represent trits, both balanced and unbalanced. pub mod trit; /// Types and traits used to represent trytes and buffers of trytes. pub mod tryte; #[cfg(feature = "serde1")] mod serde; use crate::raw::{RawEncoding, RawEncodingBuf}; use std::{ any, borrow::{Borrow, BorrowMut}, cmp::{self, Ordering}, convert::TryFrom, error, fmt, hash, iter::FromIterator, ops::{ Deref, DerefMut, Index, IndexMut, Neg, Range, RangeFrom, RangeFull, RangeInclusive, RangeTo, RangeToInclusive, }, }; pub use crate::{ t1b1::{T1B1Buf, T1B1}, t2b1::{T2B1Buf, T2B1}, t3b1::{T3B1Buf, T3B1}, t4b1::{T4B1Buf, T4B1}, t5b1::{T5B1Buf, T5B1}, trit::{Btrit, ShiftTernary, Trit, Utrit}, tryte::{Tryte, TryteBuf}, }; /// An error that may be produced as a result of fallible conversions. #[derive(Debug)] pub enum Error { /// A value that does not represent a valid ternary representation was encountered. InvalidRepr, } impl fmt::Display for Error { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { match self { Error::InvalidRepr => write!(f, "invalid representation"), } } } impl error::Error for Error {} /// A type that represents a buffer of trits of unknown length. /// /// This type is roughly analogous to `[T]` or [`str`]. It is an unsized type and hence is rarely /// used directly. Instead, it's more common to see it used from behind a reference (in a similar /// manner to `&[T]` and `&str`. #[derive(Hash)] #[repr(transparent)] pub struct Trits<T: RawEncoding + ?Sized = T1B1<Btrit>>(T); impl<T> Trits<T> where T: RawEncoding + ?Sized, { /// Create an empty trit slice. pub fn empty() -> &'static Self { unsafe { &*(T::empty() as *const _ as *const Self) } } /// Interpret an (`std::i8`) slice as a trit slice with the given encoding without first /// checking that the slice is valid in the given encoding. The `num_trits` parameter is used /// to specify the exact length, in trits, that the slice should be taken to have. Providing a /// slice that is not valid for this encoding is undefined behaviour. /// /// # Panics /// /// This function will panic if `num_trits` is more than can be represented with the slice in /// the given encoding. /// /// # Safety /// /// This function must only be called with an [`i8`] slice that is valid for this trit encoding /// given the specified `num_trits` length. Right now, this validity is not well-defined and so /// it is suggested that only [`i8`] slices created from existing trit slices or trit buffers /// be used. Calling this function with an invalid [`i8`] slice is undefined behaviour. pub unsafe fn from_raw_unchecked(raw: &[i8], num_trits: usize) -> &Self { debug_assert!( raw.iter().copied().all(T::is_valid), "Invalid i8 slice used to create trit slice" ); &*(T::from_raw_unchecked(raw, num_trits) as *const _ as *const _) } /// Interpret a mutable (`std::i8`) slice as a mutable trit slice with the given encoding /// without first checking that the slice is valid in the given encoding. The `num_trits` /// parameter is used to specify the exact length, in trits, that the slice should be taken to /// have. Providing a slice that is not valid for this encoding is undefined behaviour. /// /// # Panics /// /// This function will panic if `num_trits` is more than can be represented with the slice in /// the given encoding. /// /// # Safety /// /// This function must only be called with an [`i8`] slice that is valid for this trit encoding /// given the specified `num_trits` length. Right now, this validity is not well-defined and so /// it is suggested that only [`i8`] slices created from existing trit slices or trit buffers /// be used. Calling this function with an invalid [`i8`] slice is undefined behaviour. pub unsafe fn from_raw_unchecked_mut(raw: &mut [i8], num_trits: usize) -> &mut Self { debug_assert!( raw.iter().copied().all(T::is_valid), "Invalid i8 slice used to create trit slice" ); &mut *(T::from_raw_unchecked_mut(raw, num_trits) as *mut _ as *mut _) } /// Interpret an (`std::i8`) slice as a trit slice with the given encoding, checking to ensure /// that the slice is valid in the given encoding. The `num_trits` parameter is used to specify /// the exact length, in trits, that the slice should be taken to have. /// /// # Panics /// /// This function will panic if `num_trits` is more than can be represented with the slice in /// the given encoding. pub fn try_from_raw(raw: &[i8], num_trits: usize) -> Result<&Self, Error> { if raw.iter().copied().all(T::is_valid) { Ok(unsafe { Self::from_raw_unchecked(raw, num_trits) }) } else { Err(Error::InvalidRepr) } } /// Interpret a mutable (`std::i8`) slice as a mutable trit slice with the given encoding, /// checking to ensure that the slice is valid in the given encoding. The `num_trits` parameter /// is used to specify the exact length, in trits, that the slice should be taken to have. /// /// # Panics /// /// This function will panic if `num_trits` is more than can be represented with the slice in /// the given encoding. pub fn try_from_raw_mut(raw: &mut [i8], num_trits: usize) -> Result<&mut Self, Error> { if raw.iter().copied().all(T::is_valid) { Ok(unsafe { Self::from_raw_unchecked_mut(raw, num_trits) }) } else { Err(Error::InvalidRepr) } } /// Returns `true` if the trit slice is empty. pub fn is_empty(&self) -> bool { self.len() == 0 } /// Returns the number of trits in this trit slice. pub fn len(&self) -> usize { self.0.len() } /// Interpret this slice as an (`std::i8`) slice. /// /// # Panics /// /// This function will panic if the slice is not byte-aligned. pub fn as_i8_slice(&self) -> &[i8] { self.0.as_i8_slice() } /// Interpret this slice as a mutable (`std::i8`) slice. /// /// # Panics /// /// This function will panic if the slice is not byte-aligned. /// /// # Safety /// /// This function is marked `unsafe` because modification of the trit slice in a manner that is /// not valid for this encoding is undefined behaviour. pub unsafe fn as_i8_slice_mut(&mut self) -> &mut [i8] { self.0.as_i8_slice_mut() } /// Fetch the trit at the given index of this trit slice without first checking whether the /// index is in bounds. Providing an index that is not less than the length of this slice is /// undefined behaviour. /// /// This is perhaps the 'least bad' `unsafe` function in this crate: not because any form of /// undefined behaviour is better or worse than another (after all, the point of undefined /// behaviour is that it is undefined) but because it's the easiest to use correctly. /// /// # Safety /// /// An index with a value less then the result of [`Trits::len`] must be used. Any other value /// is undefined behaviour. pub unsafe fn get_unchecked(&self, index: usize) -> T::Trit { debug_assert!( index < self.0.len(), "Attempt to get trit at index {}, but length of slice is {}", index, self.len(), ); self.0.get_unchecked(index) } /// Set the trit at the given index of this trit slice without first checking whether the /// index is in bounds. Providing an index that is not less than the length of this slice is /// undefined behaviour. /// /// This is perhaps the 'least bad' `unsafe` function in this crate: not because any form of /// undefined behaviour is better or worse than another (after all, the point of undefined /// behaviour is that it is undefined) but because it's the easiest to use correctly. /// /// # Safety /// /// An index with a value less then the result of [`Trits::len`] must be used. Any other value /// is undefined behaviour. pub unsafe fn set_unchecked(&mut self, index: usize, trit: T::Trit) { debug_assert!( index < self.0.len(), "Attempt to set trit at index {}, but length of slice is {}", index, self.len(), ); self.0.set_unchecked(index, trit); } /// Fetch the trit at the given index of this trit slice, if the index is valid. pub fn get(&self, index: usize) -> Option<T::Trit> { if index < self.0.len() { unsafe { Some(self.get_unchecked(index)) } } else { None } } /// Set the trit at the given index of this mutable trit slice, if the index is valid. /// /// # Panics /// /// This function will panic if the index is not less than the length of this slice. // TODO: Should we return `Option<()>` instead? pub fn set(&mut self, index: usize, trit: T::Trit) { assert!( index < self.0.len(), "Attempt to set trit at index {}, but length of slice is {}", index, self.len(), ); unsafe { self.set_unchecked(index, trit) }; } /// Returns an iterator over the trits in this slice. /// /// Using this function is significantly faster than calling [`Trits::get`] in a loop and /// should be used where possible. pub fn iter(&self) -> impl DoubleEndedIterator<Item = T::Trit> + ExactSizeIterator<Item = T::Trit> + '_ { (0..self.0.len()).map(move |idx| unsafe { self.0.get_unchecked(idx) }) } /// Returns a subslice of this slice with the given range of trits. /// /// # Panics /// /// This function will panic if called with a range that contains indices outside this slice, /// or the start of the range is greater than its end. pub fn subslice(&self, range: Range<usize>) -> &Self { assert!( range.end >= range.start && range.end <= self.len(), "Sub-slice range must be within the bounds of the source trit slice", ); unsafe { &*(self.0.slice_unchecked(range) as *const _ as *const Self) } } /// Returns a mutable subslice of this mutable slice with the given range of trits. /// /// # Panics /// /// This function will panic if called with a range that contains indices outside this slice, /// or the start of the range is greater than its end. pub fn subslice_mut(&mut self, range: Range<usize>) -> &mut Self { assert!( range.end >= range.start && range.end <= self.len(), "Sub-slice range must be within the bounds of the source trit slice", ); unsafe { &mut *(self.0.slice_unchecked_mut(range) as *mut _ as *mut Self) } } /// Copy the trits from a trit slice into this mutable trit slice (the encoding need not be /// equivalent). /// /// # Panics /// /// This function will panic if the length of the slices are different. pub fn copy_from<U: RawEncoding<Trit = T::Trit> + ?Sized>(&mut self, trits: &Trits<U>) { assert!( self.len() == trits.len(), "Source trit slice must be the same length as target" ); for (i, trit) in trits.iter().enumerate() { unsafe { self.set_unchecked(i, trit); } } } /// Fill this mutable trit slice with copied of the given trit. pub fn fill(&mut self, trit: T::Trit) { for i in 0..self.len() { unsafe { self.set_unchecked(i, trit); } } } /// Copy the contents of this trit slice into a new [`TritBuf`] with the same encoding. This /// function is analogous to `to_vec` method implemented on ordinary slices. pub fn to_buf<U: RawEncodingBuf<Slice = T>>(&self) -> TritBuf<U> { // TODO: A faster impl than this! self.iter().collect() } /// Return an iterator over distinct, non-overlapping subslices of this trit slice, each with /// the given chunk length. If the length of the trit slice is not a multiple of the given /// chunk length, the last slice provided by the iterator will be smaller to compensate. /// /// # Panics /// /// This function will panic if the given chunk length is `0`. pub fn chunks( &self, chunk_len: usize, ) -> impl DoubleEndedIterator<Item = &Self> + ExactSizeIterator<Item = &Self> + '_ { assert!(chunk_len > 0, "Chunk length must be non-zero"); (0..self.len()) .step_by(chunk_len) .map(move |i| &self[i..(i + chunk_len).min(self.len())]) } /// Encode the contents of this trit slice into a `TritBuf` with a different encoding. pub fn encode<U>(&self) -> TritBuf<U> where U: RawEncodingBuf, U::Slice: RawEncoding<Trit = T::Trit>, { self.iter().collect() } } impl<T> Trits<T> where T: RawEncoding<Trit = Btrit> + ?Sized, { /// Returns an iterator over the trytes represented within this slice. /// /// For encodings that are representation-compatible with trytes, such as [`T3B1`], use /// [`Trits::as_trytes`] instead since it is faster and more capable. pub fn iter_trytes(&self) -> impl DoubleEndedIterator<Item = Tryte> + ExactSizeIterator<Item = Tryte> + '_ { assert!(self.len() % 3 == 0, "Trit slice length must be a multiple of 3"); self.chunks(3) .map(|trits| Tryte::from_trits([trits.get(0).unwrap(), trits.get(1).unwrap(), trits.get(2).unwrap()])) } /// Negate each trit in this buffer. /// /// This has the effect of making the trit buffer negative when expressed in numeric form. pub fn negate(&mut self) { for i in 0..self.len() { unsafe { let t = self.get_unchecked(i); self.set_unchecked(i, -t); } } } } /// These functions are only implemented for trit slices with the [`T1B1`] encoding because other /// encodings are compressed and do not support handing out references to their internal trits. /// [`T1B1`] is an exception because its trits are strictly byte-aligned. /// /// This fact also implies that [`T1B1`] is the fastest encoding for general-purpose manipulation /// of trits. impl<T: Trit> Trits<T1B1<T>> { /// View this trit slice as an ordinary slice of trits. pub fn as_raw_slice(&self) -> &[T] { self.0.as_raw_slice() } /// View this mutable trit slice as an ordinary slice of mutable trits. pub fn as_raw_slice_mut(&mut self) -> &mut [T] { self.0.as_raw_slice_mut() } /// Return an iterator over distinct, non-overlapping mutable subslices of this mutable trit /// slice, each with the given chunk length. If the length of the trit slice is not a multiple /// of the given chunk length, the last slice provided by the iterator will be smaller to compensate. /// /// # Panics /// /// This function will panic if the given chunk length is `0`. // Q: Why isn't this method on Trits<T>? // A: Because overlapping slice lifetimes make this unsound on squashed encodings pub fn chunks_mut(&mut self, chunk_len: usize) -> impl Iterator<Item = &mut Self> + '_ { assert!(chunk_len > 0, "Chunk length must be non-zero"); (0..self.len()).step_by(chunk_len).scan(self, move |this, _| { let idx = chunk_len.min(this.len()); let (a, b) = Trits::split_at_mut(this, idx); *this = b; Some(a) }) } /// Divides this mutable slice into two mutually exclusive mutable slices at the given index. /// /// The first slice will contain the indices within the range `0..mid` and the second `mid..len`. fn split_at_mut<'a>(this: &mut &'a mut Self, mid: usize) -> (&'a mut Self, &'a mut Self) { assert!( mid <= this.len(), "Cannot split at an index outside the trit slice bounds" ); ( unsafe { &mut *(this.0.slice_unchecked_mut(0..mid) as *mut _ as *mut Self) }, unsafe { &mut *(this.0.slice_unchecked_mut(mid..this.len()) as *mut _ as *mut Self) }, ) } /// Returns a mutable iterator over the trits in this slice. /// /// Using this function is significantly faster than calling [`Trits::set`] in a loop and /// should be used where possible. pub fn iter_mut(&mut self) -> slice::IterMut<T> { self.as_raw_slice_mut().iter_mut() } } impl<'a, T: Trit> From<&'a [T]> for &'a Trits<T1B1<T>> { fn from(xs: &'a [T]) -> Self { unsafe { Trits::from_raw_unchecked(&*(xs as *const _ as *const _), xs.len()) } } } impl<'a, T: Trit> From<&'a mut [T]> for &'a mut Trits<T1B1<T>> { fn from(xs: &'a mut [T]) -> Self { unsafe { Trits::from_raw_unchecked_mut(&mut *(xs as *mut _ as *mut _), xs.len()) } } } impl<'a, T: Trit> From<&'a Trits<T1B1<T>>> for &'a [T] { fn from(trits: &'a Trits<T1B1<T>>) -> Self { trits.as_raw_slice() } } impl<'a, T: Trit> From<&'a mut Trits<T1B1<T>>> for &'a mut [T] { fn from(trits: &'a mut Trits<T1B1<T>>) -> Self { trits.as_raw_slice_mut() } } /// These functions are only implemented for trit slices with the [`T3B1`] encoding because only /// the [`T3B1`] encoding has a representation compatible with a slice of `Tryte`s. If you find /// yourself commonly needing to convert between trits and trytes, [`T3B1`] is the encoding to use. impl Trits<T3B1> { /// Interpret this trit slice as a [`Tryte`] slice. /// /// # Panics /// /// This function will panic if the length of the slice is not a multiple of `3`, or if the /// slice is not byte-aligned. pub fn as_trytes(&self) -> &[Tryte] { assert!(self.len() % 3 == 0, "Trit slice length must be a multiple of 3"); unsafe { &*(self.as_i8_slice() as *const _ as *const _) } } /// Interpret this mutable trit slice as a mutable [`Tryte`] slice. /// /// # Panics /// /// This function will panic if the length of the slice is not a multiple of `3`, or if the /// slice is not byte-aligned. pub fn as_trytes_mut(&mut self) -> &mut [Tryte] { assert!(self.len() % 3 == 0, "Trit slice length must be a multiple of 3"); unsafe { &mut *(self.as_i8_slice_mut() as *mut _ as *mut _) } } } impl<T, U> cmp::PartialEq<Trits<U>> for Trits<T> where T: RawEncoding + ?Sized, U: RawEncoding<Trit = T::Trit> + ?Sized, { fn eq(&self, other: &Trits<U>) -> bool { self.len() == other.len() && self.iter().zip(other.iter()).all(|(a, b)| a == b) } } impl<T, U> cmp::PartialOrd<Trits<U>> for Trits<T> where T: RawEncoding + ?Sized, U: RawEncoding<Trit = T::Trit> + ?Sized, T::Trit: cmp::PartialOrd, { fn partial_cmp(&self, other: &Trits<U>) -> Option<Ordering> { if self.len() != other.len() { return None; } for (a, b) in self.iter().zip(other.iter()) { match a.partial_cmp(&b) { Some(Ordering::Equal) => continue, other_order => return other_order, } } Some(Ordering::Equal) } } impl<'a, T: RawEncoding + ?Sized> fmt::Debug for &'a Trits<T> { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { write!(f, "Trits<{}> [", any::type_name::<T>())?; for (i, trit) in self.iter().enumerate() { if i != 0 { write!(f, ", ")?; } write!(f, "{:?}", trit)?; } write!(f, "]") } } // x impl<T: RawEncoding + ?Sized> Index<usize> for Trits<T> { type Output = T::Trit; fn index(&self, index: usize) -> &Self::Output { self.get(index).expect("Index out of range").as_arbitrary_ref() } } // x..y impl<T: RawEncoding + ?Sized> Index<Range<usize>> for Trits<T> { type Output = Self; fn index(&self, range: Range<usize>) -> &Self::Output { self.subslice(range) } } impl<T: RawEncoding + ?Sized> IndexMut<Range<usize>> for Trits<T> { fn index_mut(&mut self, range: Range<usize>) -> &mut Self::Output { self.subslice_mut(range) } } // x.. impl<T: RawEncoding + ?Sized> Index<RangeFrom<usize>> for Trits<T> { type Output = Self; fn index(&self, range: RangeFrom<usize>) -> &Self::Output { self.subslice(range.start..self.len()) } } impl<T: RawEncoding + ?Sized> IndexMut<RangeFrom<usize>> for Trits<T> { fn index_mut(&mut self, range: RangeFrom<usize>) -> &mut Self::Output { self.subslice_mut(range.start..self.len()) } } // .. impl<T: RawEncoding + ?Sized> Index<RangeFull> for Trits<T> { type Output = Self; fn index(&self, _range: RangeFull) -> &Self::Output { self } } impl<T: RawEncoding + ?Sized> IndexMut<RangeFull> for Trits<T> { fn index_mut(&mut self, _range: RangeFull) -> &mut Self::Output { self } } // x..=y impl<T: RawEncoding + ?Sized> Index<RangeInclusive<usize>> for Trits<T> { type Output = Self; fn index(&self, range: RangeInclusive<usize>) -> &Self::Output { self.subslice(*range.start()..*range.end() + 1) } } impl<T: RawEncoding + ?Sized> IndexMut<RangeInclusive<usize>> for Trits<T> { fn index_mut(&mut self, range: RangeInclusive<usize>) -> &mut Self::Output { self.subslice_mut(*range.start()..*range.end() + 1) } } // ..y impl<T: RawEncoding + ?Sized> Index<RangeTo<usize>> for Trits<T> { type Output = Self; fn index(&self, range: RangeTo<usize>) -> &Self::Output { self.subslice(0..range.end) } } impl<T: RawEncoding + ?Sized> IndexMut<RangeTo<usize>> for Trits<T> { fn index_mut(&mut self, range: RangeTo<usize>) -> &mut Self::Output { self.subslice_mut(0..range.end) } } // ..=y impl<T: RawEncoding + ?Sized> Index<RangeToInclusive<usize>> for Trits<T> { type Output = Self; fn index(&self, range: RangeToInclusive<usize>) -> &Self::Output { self.subslice(0..range.end + 1) } } impl<T: RawEncoding + ?Sized> IndexMut<RangeToInclusive<usize>> for Trits<T> { fn index_mut(&mut self, range: RangeToInclusive<usize>) -> &mut Self::Output { self.subslice_mut(0..range.end + 1) } } impl<T: RawEncoding + ?Sized> ToOwned for Trits<T> { type Owned = TritBuf<T::Buf>; fn to_owned(&self) -> Self::Owned { self.to_buf() } } impl<T: RawEncoding + ?Sized> fmt::Display for Trits<T> { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { write!(f, "[")?; for (i, t) in self.iter().enumerate() { if i != 0 { write!(f, ", ")?; } write!(f, "{}", t)?; } write!(f, "]") } } /// A buffer containing trits. /// /// This type is roughly analogous to [`Vec`] or [`String`]. It supports pushing and popping trits /// and dereferences to [`Trits`]. It may be borrowed as a trit slice, either mutably or immutably. #[derive(Clone)] #[repr(transparent)] pub struct TritBuf<T: RawEncodingBuf = T1B1Buf<Btrit>>(T); impl<T: RawEncodingBuf> TritBuf<T> { /// Create a new empty [`TritBuf`]. pub fn new() -> Self { Self::default() } /// Create a new empty [`TritBuf`], backed by the given capacity, `cap`. The resulting /// [`TritBuf`] will contain at least enough space to contain `cap` trits without needing to /// reallocate. pub fn with_capacity(cap: usize) -> Self { Self(T::with_capacity(cap)) } /// Create a new [`TritBuf`] of the given length, filled with copies of the provided trit. pub fn filled(len: usize, trit: <T::Slice as RawEncoding>::Trit) -> Self { let mut this = Self::with_capacity(len); for _ in 0..len { this.push(trit); } this } /// Create a new [`TritBuf`] of the given length, filled with zero trit. pub fn zeros(len: usize) -> Self { Self::filled(len, <T::Slice as RawEncoding>::Trit::zero()) } /// Create a new [`TritBuf`] containing the trits from the given slice of trits. pub fn from_trits(trits: &[<T::Slice as RawEncoding>::Trit]) -> Self { Self(T::from_trits(trits)) } /// Push a trit to the back of this [`TritBuf`]. pub fn push(&mut self, trit: <T::Slice as RawEncoding>::Trit) { self.0.push(trit); } /// Pop a trit from the back of this [`TritBuf`], returning it if successful. pub fn pop(&mut self) -> Option<<T::Slice as RawEncoding>::Trit> { self.0.pop() } /// Extracts a trit slice containing the data within this buffer. /// /// Note that [`TritBuf`] dereferences to `Trits` anyway, so it's usually sufficient to take /// a reference to [`TritBuf`] or to just call `&Trits` methods on it rather than explicitly /// calling this method first. pub fn as_slice(&self) -> &Trits<T::Slice> { unsafe { &*(self.0.as_slice() as *const T::Slice as *const Trits<T::Slice>) } } /// Extracts a mutable trit slice containing the data within this buffer. /// /// Note that [`TritBuf`] dereferences to `Trits` anyway, so it's usually sufficient to take /// a reference to [`TritBuf`] or to just call `&mut Trits` methods on it rather /// explicitly calling this method first. pub fn as_slice_mut(&mut self) -> &mut Trits<T::Slice> { unsafe { &mut *(self.0.as_slice_mut() as *mut T::Slice as *mut Trits<T::Slice>) } } } impl TritBuf<T3B1Buf> { /// Pad the trit buffer with [`Btrit::Zero`] until the buffer's length is a multiple of 3. /// /// This method is often used in conjunction with [`Trites::as_trytes`]. pub fn pad_zeros(&mut self) { while self.len() % 3 != 0 { self.push(Btrit::Zero); } } /// Pad the trit buffer with [`Btrit::Zero`] until the buffer's length is a multiple of 3. /// /// This method is often used in conjunction with [`Trites::as_trytes`]. pub fn padded_zeros(mut self) -> Self { self.pad_zeros(); self } } impl<T: RawEncodingBuf> Neg for TritBuf<T> where T::Slice: RawEncoding<Trit = Btrit>, { type Output = Self; fn neg(mut self) -> Self { self.negate(); self } } impl<T: RawEncodingBuf> TritBuf<T> where T::Slice: RawEncoding<Trit = Btrit>, { /// Create a new [`TritBuf`] containing the trits given by the slice of i8s. pub fn from_i8s(trits: &[i8]) -> Result<Self, <Btrit as TryFrom<i8>>::Error> { trits.iter().map(|x| Btrit::try_from(*x)).collect() } } impl<T: RawEncodingBuf> TritBuf<T> where T::Slice: RawEncoding<Trit = Utrit>, { /// Create a new [`TritBuf`] containing the trits given by the slice of u8s. pub fn from_u8s(trits: &[u8]) -> Result<Self, <Btrit as TryFrom<u8>>::Error> { trits.iter().map(|x| Utrit::try_from(*x)).collect() } } impl<T: RawEncodingBuf> Default for TritBuf<T> { fn default() -> Self { Self(T::new()) } } impl<T> TritBuf<T1B1Buf<T>> where T: Trit, T::Target: Trit, { /// Transform this [`TritBuf`] into a shifted representation. If the buffer contains /// balanced trits ([`Btrit`]), the returned buffer will contain unbalanced trits ([`Utrit`]). pub fn into_shifted(self) -> TritBuf<T1B1Buf<<T as ShiftTernary>::Target>> { TritBuf(self.0.into_shifted()) } } impl<T: RawEncodingBuf, U: RawEncodingBuf> PartialEq<TritBuf<U>> for TritBuf<T> where T::Slice: RawEncoding, U::Slice: RawEncoding<Trit = <T::Slice as RawEncoding>::Trit>, { fn eq(&self, other: &TritBuf<U>) -> bool { self.as_slice() == other.as_slice() } } impl<T: RawEncodingBuf> Deref for TritBuf<T> { type Target = Trits<T::Slice>; fn deref(&self) -> &Self::Target { self.as_slice() } } impl<T: RawEncodingBuf> DerefMut for TritBuf<T> { fn deref_mut(&mut self) -> &mut Self::Target { self.as_slice_mut() } } impl<T: RawEncodingBuf> FromIterator<<T::Slice as RawEncoding>::Trit> for TritBuf<T> { fn from_iter<I: IntoIterator<Item = <T::Slice as RawEncoding>::Trit>>(iter: I) -> Self { let iter = iter.into_iter(); let mut this = Self::with_capacity(iter.size_hint().0); for trit in iter { this.push(trit); } this } } impl<T> hash::Hash for TritBuf<T> where T: RawEncodingBuf, T::Slice: hash::Hash, { fn hash<H: hash::Hasher>(&self, hasher: &mut H) { (**self).hash(hasher) } } impl<T: RawEncodingBuf> fmt::Debug for TritBuf<T> { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { write!(f, "TritBuf<{}> [", any::type_name::<T>())?; for (i, trit) in self.iter().enumerate() { if i != 0 { write!(f, ", ")?; } write!(f, "{:?}", trit)?; } write!(f, "]") } } impl<T: RawEncodingBuf> fmt::Display for TritBuf<T> { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { write!(f, "{}", self.as_slice()) } } impl<T: RawEncodingBuf> Borrow<Trits<T::Slice>> for TritBuf<T> { fn borrow(&self) -> &Trits<T::Slice> { self.as_slice() } } impl<T: RawEncodingBuf> BorrowMut<Trits<T::Slice>> for TritBuf<T> { fn borrow_mut(&mut self) -> &mut Trits<T::Slice> { self.as_slice_mut() } }