Trait asn1_rs::FromBer

pub trait FromBer<'a, E = Error>: Sized {
    // Required method
    fn from_ber(bytes: &'a [u8]) -> ParseResult<'_, Self, E>;
}

Base trait for BER object parsers

Library authors should usually not directly implement this trait, but should prefer implementing the TryFrom<Any> trait, which offers greater flexibility and provides an equivalent FromBer implementation for free.

Examples

use asn1_rs::{Any, Result, Tag};
use std::convert::TryFrom;

// The type to be decoded
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct MyType(pub u32);

impl<'a> TryFrom<Any<'a>> for MyType {
    type Error = asn1_rs::Error;

    fn try_from(any: Any<'a>) -> Result<MyType> {
        any.tag().assert_eq(Tag::Integer)?;
        // for this fictive example, the type contains the number of characters
        let n = any.data.len() as u32;
        Ok(MyType(n))
    }
}

// The above code provides a `FromBer` implementation for free.

// Example of parsing code:
use asn1_rs::FromBer;

let input = &[2, 1, 2];
// Objects can be parsed using `from_ber`, which returns the remaining bytes
// and the parsed object:
let (rem, my_type) = MyType::from_ber(input).expect("parsing failed");

Required Methods

fn from_ber(bytes: &'a [u8]) -> ParseResult<'_, Self, E>

Attempt to parse input bytes into a BER object

Object Safety

This trait is not object safe.

Implementations on Foreign Types

impl<'a, T> FromBer<'a> for Option<T>

where T: FromBer<'a>,

fn from_ber(bytes: &'a [u8]) -> ParseResult<'_, Self>

Implementors

impl<'a> FromBer<'a> for Any<'a>

impl<'a> FromBer<'a> for Header<'a>

impl<'a, T, E> FromBer<'a, E> for TaggedParser<'a, Explicit, T, E>

where T: FromBer<'a, E>, E: From<Error>,

impl<'a, T, E> FromBer<'a, E> for TaggedParser<'a, Implicit, T, E>

where T: TryFrom<Any<'a>, Error = E> + Tagged, E: From<Error>,

impl<'a, T, E> FromBer<'a, E> for T

where T: TryFrom<Any<'a>, Error = E>, E: From<Error>,