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mirror of https://github.com/TomHarte/CLK.git synced 2024-06-25 18:30:07 +00:00

Introduce a template for numeric coding.

This commit is contained in:
Thomas Harte 2023-01-17 13:26:11 -05:00
parent bb6ceafe0e
commit f6e601daff
2 changed files with 66 additions and 0 deletions

64
Numeric/NumericCoder.hpp Normal file
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@ -0,0 +1,64 @@
//
// NumericCoder.hpp
// Clock Signal
//
// Created by Thomas Harte on 17/01/2023.
// Copyright © 2023 Thomas Harte. All rights reserved.
//
#ifndef NumericCoder_hpp
#define NumericCoder_hpp
namespace Numeric {
/// Stores and retrieves an arbitrary number of fields into an int with arbitrary modulos.
///
/// E.g. NumericEncoder<8, 3, 14> establishes an encoder and decoder for three fields,
/// the first is modulo 8, the second is modulo 3, the third is modulo 14.
///
/// NumericEncoder<8, 3, 14>::encode<2>(v, 9) will mutate v so that the third field
/// (i.e. field 2) has value 9.
template <int... Sizes> class NumericCoder {
public:
/// Modifies @c target to hold @c value at @c index.
template <int index> static void encode(int &target, int value) {
static_assert(index < sizeof...(Sizes), "Index must be within range");
NumericEncoderImp<Sizes...>::template encode<index, 0, 1>(target, value);
}
/// @returns The value from @c source at @c index.
template <int index> static int decode(int source) {
static_assert(index < sizeof...(Sizes), "Index must be within range");
return NumericEncoderImp<Sizes...>::template decode<index, 0, 1>(source);
}
private:
template <int size, int... Tail>
struct NumericEncoderImp {
template <int index, int i, int divider> static void encode(int &target, int value) {
if constexpr (i == index) {
const int suffix = target % divider;
target /= divider;
target -= target % size;
target += value % size;
target *= divider;
target += suffix;
} else {
NumericEncoderImp<Tail...>::template encode<index, i+1, divider*size>(target, value);
}
}
template <int index, int i, int divider> static int decode(int source) {
if constexpr (i == index) {
return (source / divider) % size;
} else {
return NumericEncoderImp<Tail...>::template decode<index, i+1, divider*size>(source);
}
}
};
};
}
#endif /* NumericCoder_hpp */

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@ -1430,6 +1430,7 @@
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@ -3304,6 +3305,7 @@
4BD155312716362A00410C6E /* BitSpread.hpp */,
4B7BA03E23D55E7900B98D9E /* CRC.hpp */,
4B7BA03F23D55E7900B98D9E /* LFSR.hpp */,
4B66E1A8297719270057ED0F /* NumericCoder.hpp */,
4BB5B995281B1D3E00522DA9 /* RegisterSizes.hpp */,
4BFEA2F12682A90200EBF94C /* Sizes.hpp */,
);