ionpak-thermostat/firmware/src/command_parser.rs

153 lines
4.3 KiB
Rust

use logos::Logos;
use super::session::ReportMode;
#[derive(Logos, Debug, PartialEq)]
enum Token {
#[end]
End,
#[error]
Error,
#[token = "Quit"]
Quit,
#[token = "show"]
Show,
#[token = "channel"]
Channel,
#[token = "report"]
Report,
#[token = "mode"]
Mode,
#[token = "off"]
Off,
#[token = "once"]
Once,
#[token = "continuous"]
Continuous,
#[token = "enable"]
Enable,
#[token = "disable"]
Disable,
#[token = "setup"]
Setup,
#[regex = "[0-9]+"]
Number,
}
#[derive(Debug)]
pub enum Error {
Parser,
UnexpectedEnd,
UnexpectedToken(Token),
NoSuchChannel,
NoSuchSetup,
}
#[derive(Debug)]
pub enum ShowCommand {
ReportMode,
}
#[derive(Debug)]
pub enum ChannelCommand {
Enable,
Disable,
Setup(u8),
}
#[derive(Debug)]
pub enum Command {
Quit,
Show(ShowCommand),
Report(ReportMode),
Channel(u8, ChannelCommand),
}
const CHANNEL_IDS: &'static [&'static str] = &[
"0", "1", "2", "3",
];
const SETUP_IDS: &'static [&'static str] = CHANNEL_IDS;
impl Command {
pub fn parse(input: &str) -> Result<Self, Error> {
let mut lexer = Token::lexer(input);
/// Match against a set of expected tokens
macro_rules! choice {
[$($token: tt => $block: stmt,)*] => {
match lexer.token {
$(
Token::$token => {
lexer.advance();
$block
}
)*
Token::End => Err(Error::UnexpectedEnd),
_ => Err(Error::UnexpectedToken(lexer.token))
}
};
}
/// Expecting no further tokens
macro_rules! end {
($result: expr) => {
match lexer.token {
Token::End => Ok($result),
_ => Err(Error::UnexpectedToken(lexer.token)),
}
};
}
// Command grammar
choice![
Quit => Ok(Command::Quit),
Report => choice![
Mode => choice![
End => end!(Command::Show(ShowCommand::ReportMode)),
Off => Ok(Command::Report(ReportMode::Off)),
Once => Ok(Command::Report(ReportMode::Once)),
Continuous => Ok(Command::Report(ReportMode::Continuous)),
],
End => Ok(Command::Report(ReportMode::Once)),
],
Channel => choice![
Number => {
let channel = CHANNEL_IDS.iter()
.position(|id| *id == lexer.slice());
match channel {
Some(channel) => {
choice![
Enable => Ok(Command::Channel(
channel as u8,
ChannelCommand::Enable
)),
Disable => Ok(Command::Channel(
channel as u8,
ChannelCommand::Enable
)),
Setup => choice![
Number => {
let setup = SETUP_IDS.iter()
.position(|id| *id == lexer.slice());
match setup {
Some(setup) =>
end!(Command::Channel(
channel as u8,
ChannelCommand::Setup(setup as u8)
)),
None =>
Err(Error::NoSuchSetup)
}
},
],
]
}
None => Err(Error::NoSuchChannel)
}
},
],
]
}
}