Crate untwine

A declarative parsing library for extremely simple, concise parsing. See parser! for usage instructions.

Example JSON parser using Untwine:

untwine::parser! {
    [error = ParseJSONError]
    sep = #{char::is_ascii_whitespace}*;
    comma = sep "," sep;
    int: num=<"-"? '0'-'9'+> -> JSONValue { JSONValue::Int(num.parse()?) }
    float: num=<"-"? '0'-'9'+ "." '0'-'9'+> -> JSONValue { JSONValue::Float(num.parse()?) }
    str_char = ("\\" . | [^"\""]) -> char;
    str: "\"" chars=str_char* "\"" -> JSONValue { JSONValue::String(chars.into_iter().collect()) }
    null: "null" -> JSONValue { JSONValue::Null }
    bool: bool=<"true" | "false"> -> JSONValue { JSONValue::Bool(bool == "true") }
    list: "[" sep values=json$comma* sep "]" -> JSONValue { JSONValue::List(values) }
    map_entry: key=str sep ":" sep value=json -> (String, JSONValue) { (key.string().unwrap(), value) }
    map: "{" sep values=map_entry$comma* sep "}" -> JSONValue { JSONValue::Map(values.into_iter().collect()) }
    pub json = (bool | null | str | float | int | list | map) -> JSONValue;
}

Re-exports

pub use error::ParserError;

pub use recoverable::Recoverable;

Modules

attr

context

error

parser

parsers

prelude

pretty

recoverable

Macros

parser

Generate parsers using a series of declarative patterns and blocks evaluating their values.

Structs

Span

Represents data corresponding to a specific portion of a parsing input.

Functions

parse

Parse a value with a parser function created by the parser! block.

parse_pretty

Parse a value with a parser function created by the parser! block, and convert the error to a pretty string if there is one.

parser_repl

Launches a (very) simple REPL where you can enter individual lines and see the parser output, useful for testing. Multiline inputs are not supported, so literal \n in the input will be replaced with a newline.