prefix-hex 0.4.0

Encoding and decoding of hex strings with 0x prefix.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69

// Copyright 2022 IOTA Stiftung
// SPDX-License-Identifier: Apache-2.0

use alloc::{boxed::Box, format, string::String, vec::Vec};

use crate::{strip_prefix, Error, FromHexPrefixed, ToHexPrefixed};

impl FromHexPrefixed for Vec<u8> {
    fn from_hex_prefixed(hex: &str) -> Result<Self, Error> {
        let hex = strip_prefix(hex)?;
        hex::decode(hex).map_err(Into::into)
    }
}

impl ToHexPrefixed for Vec<u8> {
    fn to_hex_prefixed(self) -> String {
        format!("0x{}", hex::encode(self))
    }
}

impl<const N: usize> FromHexPrefixed for [u8; N]
where
    Self: hex::FromHex,
{
    fn from_hex_prefixed(hex: &str) -> Result<Self, Error> {
        let hex = strip_prefix(hex)?;
        let mut buffer = [0; N];
        hex::decode_to_slice(hex, &mut buffer).map_err(|e| match e {
            hex::FromHexError::InvalidStringLength | hex::FromHexError::OddLength => Error::InvalidStringLengthSlice {
                expected: N * 2,
                actual: hex.len(),
            },
            _ => e.into(),
        })?;
        Ok(buffer)
    }
}

impl<const N: usize> ToHexPrefixed for [u8; N]
where
    Self: hex::ToHex,
{
    fn to_hex_prefixed(self) -> String {
        format!("0x{}", hex::encode(self))
    }
}

impl<const N: usize> ToHexPrefixed for &[u8; N]
where
    [u8; N]: hex::ToHex,
{
    fn to_hex_prefixed(self) -> String {
        format!("0x{}", hex::encode(self))
    }
}

macro_rules! impl_for_as_ref_type {
    ($type:ty) => {
        impl ToHexPrefixed for $type {
            fn to_hex_prefixed(self) -> String {
                format!("0x{}", hex::encode(self))
            }
        }
    };
}

impl_for_as_ref_type!(Box<[u8]>);
impl_for_as_ref_type!(&Box<[u8]>);
impl_for_as_ref_type!(&[u8]);