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
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94

//! serialization library built with a combinator design similar to nom.
//!
//! Serializers are built up from single purpose serializers, like `slice`
//! to write a raw byte slice, or `be_u16` to write a `u16` integer in big
//! endian form.
//!
//! Those small serializers can then be assembled by using combinators.
//! As an example, `all(["abcd", "efgh", "ijkl"].iter().map(string))(output)`
//! will write `"abcdefghijkl"` to `output`.
#![cfg_attr(not(feature = "std"), no_std)]

/// lib module necessary to reexport what we need from std in `no_std` mode
pub mod lib {
  #[cfg(feature = "std")]
  pub mod std {
    pub mod io {
      pub use std::io::{Write, Result, Error, Cursor};
    }
    pub use std::{cmp, fmt, iter, mem, result, slice};
  }

  #[cfg(not(feature = "std"))]
  pub mod std {
    pub use core::{cmp, iter, mem, result, slice};
    #[macro_use]
    pub use core::fmt;

    pub mod io {
      // there's no real io error on a byte slice
      pub type Error = ();
      pub type Result<T> = core::result::Result<T, Error>;

      pub trait Write {
        fn write(&mut self, buf: &[u8]) -> Result<usize>;
      }

      impl Write for &mut [u8] {
        fn write(&mut self, data: &[u8]) -> Result<usize> {
          let amt = core::cmp::min(data.len(), self.len());
          let (a, b) = core::mem::replace(self, &mut []).split_at_mut(amt);
          a.copy_from_slice(&data[..amt]);
          *self = b;
          Ok(amt)
        }
      }

      // Minimal re-implementation of std::io::Cursor so it
      // also works in non-std environments
      pub struct Cursor<T>(T, usize);

      impl<'a> Cursor<&'a mut [u8]> {
        pub fn new(inner: &'a mut [u8]) -> Self {
            Self(inner, 0)
        }

        pub fn into_inner(self) -> &'a mut [u8] {
            self.0
        }

        pub fn position(&self) -> u64 {
            self.1 as u64
        }

        pub fn set_position(&mut self, pos: u64) {
            self.1 = pos as usize;
        }

        pub fn get_mut(&mut self) -> &mut [u8] {
            self.0
        }

        pub fn get_ref(&self) -> &[u8] {
            self.0
        }
      }

      impl<'a> Write for Cursor<&'a mut [u8]> {
        fn write(&mut self, data: &[u8]) -> Result<usize> {
          let amt = (&mut self.0[self.1..]).write(data)?;
          self.1 += amt as usize;

          Ok(amt)
        }
      }
    }
  }
}

pub use crate::gen::*;
#[macro_use] mod gen;

mod combinators;
pub use crate::combinators::*;