ag_lcd/
errors.rs

1/// Error type for [LcdDisplay][crate::display::LcdDisplay], returned by [LcdDisplay::error][crate::display::LcdDisplay::error]
2///
3/// LcdDisplay uses an internal error code rather than the standard rust
4/// Result pattern because there are only two places in LcdDisplay where
5/// an error is returned. Unfortunately, *every* public function invokes
6/// one of those places (which has an [Infallible][core::convert::Infallible] error type, no less) and
7/// would be forced to return a result or call unwrap/expect.
8///
9/// This led to a cluttered API in which users had to handle error conditions
10/// when calling functions like [clear][crate::display::LcdDisplay::clear] and [home][crate::display::LcdDisplay::home].
11/// An internal error code which could mostly be ignored except when debugging seemed like a better option.
12#[repr(u8)]
13#[derive(Clone, Eq, PartialEq)]
14pub enum Error {
15    /// No pin RS
16    NoPinRS = 0,
17    /// No pin EN
18    NoPinEN = 1,
19    /// No pin RW
20    NoPinRW = 2,
21    /// No pin D0
22    NoPinD0 = 3,
23    /// No pin D1
24    NoPinD1 = 4,
25    /// No pin D2
26    NoPinD2 = 5,
27    /// No pin D3
28    NoPinD3 = 6,
29    /// No pin D4
30    NoPinD4 = 7,
31    /// No pin D5
32    NoPinD5 = 8,
33    /// No pin D6
34    NoPinD6 = 9,
35    /// No pin D7
36    NoPinD7 = 10,
37    /// No error
38    None = 11,
39    /// [Bus mode][crate::display::Mode] is invalid or not set
40    InvalidMode = 12,
41    /// Invalid conversion from u8 to Error
42    InvalidCode = 13,
43}
44
45impl From<u8> for Error {
46    fn from(v: u8) -> Self {
47        match v {
48            0 => Error::NoPinRS,
49            1 => Error::NoPinEN,
50            2 => Error::NoPinRW,
51            3 => Error::NoPinD0,
52            4 => Error::NoPinD1,
53            5 => Error::NoPinD2,
54            6 => Error::NoPinD3,
55            7 => Error::NoPinD4,
56            8 => Error::NoPinD5,
57            9 => Error::NoPinD6,
58            10 => Error::NoPinD7,
59            11 => Error::None,
60            12 => Error::InvalidMode,
61            _ => Error::InvalidCode,
62        }
63    }
64}
ag_lcd/errors.rs

ag_lcd/
errors.rs
