Crate async_gcode

This crate implements a GCode (RS-274) parser.

The default dialect is taken from NIST's RS274/NGC interpreter version 3. Some expensive part of that dialect such as parameters and expressions are gated behind feature – respectively parse-parameters and parse-expressions – in order to avoid dependency on dynamic allocation.

Some extension to this dialect such as checksum, trailing comments, optional values are also supported and gated behind features.

🔩 Example

use futures::stream;
use futures_executor::block_on;
use async_gcode::{Parser, Error};
let input = r"
   G21 H21. I21.098
   J-21 K-21. L-21.098
   M+21 N+21. P+21.098
   Q.098 R-.098 S+.098
   t - 21 . 33 "
   // mapping to `Result<u8, Error>` to render error conversion transparent.
   .bytes().map(Result::<_, Error>::Ok);

block_on(async {
    let mut parser = Parser::new(stream::iter(input));

    loop {
        if let Some(res) = parser.next().await {
            println!("{:?}", res);
        } else {
            break;
        }
    }
});

Erorr management

On parsing error the Parser can no longer trust its input and enters an error recovery state. No GCode or Error will be emitted until a new line character (\n) is received. Then a GCode::Execute is emitted and the parser restarts in a reliable known state.

⚙ Features

• std : Enabled by default. Allows for the use of dynamic allocation.
• parse-comments : enables the parser to return GCode::Comment(String); requires an allocator.
• parse-trailing-comment: allows line to end with a ; comment.
• parse-checksum : Enables the use of xorsum.
• parse-parameters : Enables the use of # parameters ; requires an allocator. If string-value is enabled then parameters may use string index. If optional-value is enabled then parameters value may be omitted but NOT the indices.
• parse-expressions : Enables parsing infix expressions ; requires an allocator.
• optional-value : Allows to omit in RealValue in word and parameter value positions. Parameter indices cannot be omitted nor can be literals in expressions.
• string-value : Allows RealValue to be a string. Any character preceded with \ will be used as is (useful for ").

⚠ Warning

Dev-dependencies currently leak features to dependencies. This crate requires rust-nightly to build with no_std until -Z features=dev_dep makes it to stable.

Note for future development

It might be interesting to have a look at ISO 6983 and/or ISO 14649.

During development fixed arithmetics was considered to be made available as an alternative to the floating point arithmetics especially for small target. After investigation, it does not seem to be a significant gain for the precision required by the gcode standard.

Ideally all arithmetics triggered by a theoritically valid input should be caught and not trigger a panic. For an excessive number of digit in a number may exceed the capacity of the variable used internally.

Structs

Parser

Enums

Error
GCode
Literal
RealValue