ldmc/morphisms/posint.morphism-base

```
#include <array/length-prefix.h>
```

morph_nat_as_u64_to_pos ()
      ℕ
    ~ native.UInt64
-->   ℕ
    ~ <PosInt 0 LittleEndian>
    ~ <Seq~<LengthPrefix native.UInt64> <Digit 0>~native.UInt64>
```
    dst->len = 1;
    dst->items[0] = *src;
    return 0;
```

morph_nat_as_pos_to_u64 (Endianness:Type)
      ℕ
    ~ <PosInt 0 Endianness>
    ~ <Seq~<LengthPrefix native.UInt64> <Digit 0>~native.UInt64>
-->   ℕ
    ~ native.UInt64
```
    *dst = src->items[0];
    return 0;
```

morph_posint_radix_le (SrcRadix:ℤ, DstRadix:ℤ)
      ℕ
    ~ <PosInt SrcRadix LittleEndian>
    ~ <Seq~<LengthPrefix native.UInt64> <Digit SrcRadix>~native.UInt64>
-->   ℕ
    ~ <PosInt DstRadix LittleEndian>
    ~ <Seq~<LenghtPrefix native.UInt64> <Digit DstRadix>~native.UInt64>
```
    uint64_t value = 0;

    for( uint64_t i = 0; i < src->len; ++i ) {
        value *= SrcRadix;
        value += src->items[src->len - i - 1];
    }

    length_prefix_uint64_t_array_uint64_t_clear( dst );

    #if DstRadix==0
        length_prefix_uint64_t_array_uint64_t_push( dst, value );
    #else
        if( value == 0 ) {
            length_prefix_uint64_t_array_uint64_t_push( dst, 0 );
        } else while( value > 0 ) {
            length_prefix_uint64_t_array_uint64_t_push( dst, value % DstRadix );
            value /= DstRadix;
        }
    #endif

    return 0;
```

morph_posint_radix_be (SrcRadix:ℤ, DstRadix:ℤ)
      ℕ
    ~ <PosInt SrcRadix BigEndian>
    ~ <Seq~<LengthPrefix native.UInt64> <Digit SrcRadix>~native.UInt64>
-->   ℕ
    ~ <PosInt DstRadix BigEndian>
    ~ <Seq~<LengthPrefix native.UInt64> <Digit DstRadix>~native.UInt64>
```
    uint64_t value = 0;

    for( uint64_t i = 0; i < src->len; ++i ) {
        value *= SrcRadix;
        value += src->items[i];
    }

    #if DstRadix==0
        dst->len = 1;
        dst->items[0] = value;
    #else
        uint64_t v = value;
        dst->len = 0;

        if( v == 0 ) {
            dst->len = 1;
        } else while( v ) {
            dst->len++;
            v /= DstRadix;
        }

        uint64_t i = dst->len;
        while( value > 0 ) {
            dst->items[--i] = value % DstRadix;
            value /= DstRadix;
        }
    #endif

    return 0;
```

morph_posint_endianness (Radix:ℤ)
      ℕ
    ~ <PosInt Radix LittleEndian>
    ~ <Seq~<LengthPrefix native.UInt64> <Digit Radix> ~ native.UInt64>
-->   ℕ
    ~ <PosInt Radix BigEndian>
    ~ <Seq~<LengthPrefix native.UInt64> <Digit Radix> ~ native.UInt64>
```
    return length_prefix_uint64_t_array_uint64_t_reverse( src, dst );
```

morph_posint_endianness (Radix:ℤ)
      ℕ
    ~ <PosInt Radix BigEndian>
    ~ <Seq~<LengthPrefix native.UInt64> <Digit Radix> ~ native.UInt64>
-->   ℕ
    ~ <PosInt Radix LittleEndian>
    ~ <Seq~<LengthPrefix native.UInt64> <Digit Radix> ~ native.UInt64>
```
    return length_prefix_uint64_t_array_uint64_t_reverse( src, dst );
```