rttrust 0.1.3

Rust wrapper for rt-thread
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
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84

//! Re-export [genio]

use crate::Result;
use core::fmt::Arguments;

pub use genio::*;

/// Enumeration of possible methods to seek within an I/O object.
///
/// It is used by the [`Seek`] trait.
///
/// [`Seek`]: trait.Seek.html
pub enum SeekFrom {
    /// Sets the offset to the provided number of bytes.
    Start(u64),
    /// Sets the offset to the size of this object plus the specified number of
    /// bytes.
    ///
    /// It is possible to seek beyond the end of an object, but it's an error to
    /// seek before byte 0.
    End(i64),
    /// Sets the offset to the current position plus the specified number of
    /// bytes.
    ///
    /// It is possible to seek beyond the end of an object, but it's an error to
    /// seek before byte 0.
    Current(i64),
}

/// The `Seek` trait provides a cursor which can be moved within a stream of
/// bytes.
///
/// The stream typically has a fixed size, allowing seeking relative to either
/// end or the current offset.
pub trait Seek {
    /// Seek to an offset, in bytes, in a stream.
    ///
    /// A seek beyond the end of a stream is allowed, but behavior is defined
    /// by the implementation.
    ///
    /// If the seek operation completed successfully,
    /// this method returns the new position from the start of the stream.
    /// That position can be used later with [`SeekFrom::Start`].
    ///
    /// # Errors
    ///
    /// Seeking to a negative offset is considered an error.
    ///
    /// [`SeekFrom::Start`]: enum.SeekFrom.html#variant.Start
    fn seek(&mut self, pos: SeekFrom) -> Result<i64>;
}

/// Wraper trait to extent genio's [Write](genio::Write) to be used by `write!` marco
pub trait WriteFmt: Write<WriteError = crate::RtError> {
    fn write_fmt(&mut self, fmt: Arguments<'_>) -> Result<()> {
        // Create a shim which translates a Write to a fmt::Write and saves
        // off I/O errors. instead of discarding them
        struct Adaptor<'a, T: ?Sized + 'a> {
            inner: &'a mut T,
            error: Result<()>,
        }

        impl<T: Write<WriteError = crate::RtError> + ?Sized> core::fmt::Write for Adaptor<'_, T> {
            fn write_str(&mut self, s: &str) -> core::fmt::Result {
                match self.inner.write_all(s.as_bytes()) {
                    Ok(()) => Ok(()),
                    Err(e) => {
                        self.error = Err(e);
                        Err(core::fmt::Error)
                    }
                }
            }
        }

        let mut output = Adaptor {
            inner: self,
            error: Ok(()),
        };
        match core::fmt::write(&mut output, fmt) {
            Ok(()) => Ok(()),
            Err(..) => output.error,
        }
    }
}