Struct chisel_lexers::scanner::Scanner

pub struct Scanner<'a> { /* private fields */ }

Simple LA(1) scanner which wraps itself around a source of chars and converts raw characters into CharWithCoords structures. Also provides a running buffer which can be used to accumulate input characters, prior to extracting them and tokenising them.

Implementations

impl<'a> Scanner<'a>

An input adapter used by the lexer. A Scanner is responsible for managing input state to to provide access to segments (or individual characters) from within the source input.

pub fn new(chars: &'a mut dyn Iterator<Item = char>) -> Self

New instance, based on an Iterator of char

pub fn clear(&mut self)

Reset the internal state of the scanner, without resetting the state of the underlying char iterator

pub fn pushback(&mut self)

Push the last read character (and it’s coords) onto the pushback buffer

pub fn position(&self) -> Coords

Get the absolute position in the underlying input

pub fn front(&self) -> Option<CharWithCoords>

Get the optional char at the front of the scanner buffer

pub fn back(&self) -> Option<CharWithCoords>

Get the optional char at the back of the scanner buffer

pub fn advance(&mut self, skip_whitespace: bool) -> ScannerResult<()>

Advance the scanner to the next available character, optionally skipping whitespace.

pub fn try_lookahead(&mut self) -> Option<char>

Try and look ahead one char in the input stream

pub fn advance_n( &mut self, n: usize, skip_whitespace: bool ) -> ScannerResult<()>

Advance the scanner over n available characters, returning a ScannerError if it’s not possible to do so. After calling this method the input state should be read using the other associated functions available for this type

pub fn buffer_as_string_with_span(&mut self) -> StringWithSpan

Extract the scanner buffer as a StringWithSpan. Will return an empty string if there’s nothing in the buffer

pub fn buffer_as_char_array(&mut self) -> Vec<char>

Extract the scanner buffer as a char slice

pub fn buffer_as_byte_array(&self) -> Vec<u8>

Extract the scanner buffer as a byte buffer. You just get an empty vec if the buffer is currently empty