Trait winnow::error::FinishIResult

source · 
pub trait FinishIResult<I, O, E> {
    fn finish(self) -> Result<O, E>;
    fn finish_err(self) -> Result<(I, O), E>;
}
👎Deprecated since 0.4.0: Replaced with Parser::parse
Expand description

Extension trait to convert a parser’s IResult to a more manageable type

Required Methods§

👎Deprecated since 0.4.0: Replaced with Parser::parse

Converts the parser’s IResult to a type that is more consumable by callers.

Errors if the parser is not at the end of input. See FinishIResult::finish_err if the remaining input is needed.

Panic

If the result is Err(ErrMode::Incomplete(_)), this method will panic.

  • Complete parsers: It will not be an issue, Incomplete is never used
  • Partial parsers: Incomplete will be returned if there’s not enough data for the parser to decide, and you should gather more data before parsing again. Once the parser returns either Ok(_), Err(ErrMode::Backtrack(_)) or Err(ErrMode::Cut(_)), you can get out of the parsing loop and call finish_err() on the parser’s result
Example
use winnow::prelude::*;
use winnow::character::hex_uint;
use winnow::error::Error;

struct Hex(u64);

fn parse(value: &str) -> Result<Hex, Error<String>> {
    hex_uint.map(Hex).parse_next(value).finish().map_err(Error::into_owned)
}
👎Deprecated since 0.4.0: Replaced with Parser::parse

Converts the parser’s IResult to a type that is more consumable by errors.

It keeps the same Ok branch, and merges ErrMode::Backtrack and ErrMode::Cut into the Err side.

Panic

If the result is Err(ErrMode::Incomplete(_)), this method will panic as ErrMode::Incomplete should only be set when the input is StreamIsPartial<false> which this isn’t implemented for.

Implementors§