Crate banjin 

Simple code generator for manual parsing

Attributes

Struct

There are several attributes that control behaviour of parser Each, attached to struct’s field

• starts_with = <prefix> - Specifies string with which next parse step should start(can be stacked). Errors if prefix is missing.
• ends_with = <prefix> - Specifies string with which parse step should end(can be stacked). Errors if suffix is missing. If empty, expects EOF.
• skip = <chars> - Specifies to skip characters, until not meeting character outside of specified in string.
• skip(ws) - Specifies to skip all white space characters.
• format(<format>) - Specifies list of characters that should contain value to parse from.
• format(not(<format>)) - Specifies list of characters that should contain value to parse from.

Formats

• Literal string - When string is specified as argument to format, it is used as set of characters.
• numeric - When specified, match using char::is_numeric()
• digit(<base>) - When specified, match using char::is_digit(<base>)
• ascii - When specified, match using char::is_ascii()
• alphabetic - When specified, match using char::is_alphabetic()

Enum

• format = <format> - Specifies string to match against.
• case - Specifies case sensitive match. By default it is insensitive.
• default - Specifies variant as taking default value. Should take only single String and there can be only one

Usage

Struct

use std::str::FromStr;

#[derive(banjin::Parser)]
pub struct Data {
    #[starts_with = "prefix"]
    #[skip(ws)]
    #[starts_with = "+"]
    #[skip(ws)]
    #[format(ascii)]
    #[format(digit(10))]
    pub first: u32,
    #[skip(ws)]
    #[format(not("d"))]
    #[format("13")]
    #[ends_with = "d"]
    #[ends_with = ""]
    pub second: String,
}

fn main() {
    let data = Data::from_str("prefix + 666   13d").expect("Parse");
    assert_eq!(data.first, 666);
    assert_eq!(data.second, "13");

    let data = Data::from_str("prefix + 666   13");
    assert!(data.is_err());

    let data = Data::from_str("prefix 666   13d");
    assert!(data.is_err());

    let data = Data::from_str("prefix + 666   13dg");
    assert!(data.is_err());

    let data = Data::from_str("");
    assert!(data.is_err());
}

Enum

use std::str::FromStr;

#[derive(banjin::Parser, PartialEq, Eq, Debug)]
enum Gender {
    Male,
    #[case]
    Female,
    #[default]
    Other(String)
}

fn main() {
    let gender = Gender::from_str("male").expect("Parse");
    assert_eq!(gender, Gender::Male);

    let gender = Gender::from_str("female").expect("Parse");
    match gender {
        Gender::Other(text) => assert_eq!(text, "female"),
        _ => panic!("Unexpected!")
    }

    let gender = Gender::from_str("none").expect("Parse");
    match gender {
        Gender::Other(text) => assert_eq!(text, "none"),
        _ => panic!("Unexpected!")
    }
}

Derive Macros

Parser