Struct ParserState

pub struct ParserState<'s> { /* private fields */ }

A utility class for building simple recursive-descent parsers.

Basically, a wrapper over &str with nice methods that help with parsing.

Implementations

impl<'s> ParserState<'s>

pub fn new(s: &'s str) -> Self

Creates a new parser from given input string.

pub fn parse_while( self, parser: impl FnMut(Self) -> ParseResult<(bool, Self)>, ) -> ParseResult<Self>

Applies given parsing function until it returns false and returns the final parser state.

pub fn accept(self, part: &'static str) -> ParseResult<Self>

If the input string contains given string at the beginning, returns a new parser state with given string skipped. Otherwise, returns an error.

pub fn skip_white(self) -> Self

Returns new parser state with whitespace skipped from the beginning.

pub fn parse_u16(self) -> ParseResult<(u16, Self)>

Parses a sequence of digits as an integer. Consumes characters until it finds a character that is not a digit.

An error is returned if:

• The first character is not a digit
• The integer is larger than u16

pub fn take_while(self, pred: impl FnMut(char) -> bool) -> (&'s str, Self)

Skips characters from the beginning while they satisfy given predicate and returns new parser state which

pub fn get_remaining(self) -> usize

Returns the number of remaining bytes to parse.

pub fn is_at_eof(self) -> bool

Returns true if the input string was parsed completely.

pub fn error(self, cause: ParseErrorCause) -> ParseError

Returns an error with given cause, associated with given position.

pub fn calculate_position(self, original: &str) -> Option<usize>

Given the original string, returns the 1-based position of the error in characters. If an incorrect string was given, the function may return None.

Trait Implementations

impl<'s> Clone for ParserState<'s>

fn clone(&self) -> ParserState<'s>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'s> Copy for ParserState<'s>