use std::fmt;
pub(crate) type LexerItem<Tok, Loc, Error>
= ::std::result::Result<(Loc, Tok, Loc), Error>;
#[derive(Debug, Clone, Copy, PartialEq)]
pub enum Token {
Literal,
CompressedData,
SKESK,
PKESK,
SEIP,
MDC,
AED,
OPS,
SIG,
Pop,
OpaqueContent,
}
impl fmt::Display for Token {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.write_str(&format!("{:?}", self)[..])
}
}
#[derive(Debug, Clone)]
pub enum LexicalError {
}
impl fmt::Display for LexicalError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.write_str(&format!("{:?}", self)[..])
}
}
pub(crate) struct Lexer<'input> {
iter: Box<Iterator<Item=(usize, &'input Token)> + 'input>,
}
impl<'input> Iterator for Lexer<'input> {
type Item = LexerItem<Token, usize, LexicalError>;
fn next(&mut self) -> Option<Self::Item> {
let n = self.iter.next().map(|(pos, tok)| (pos, tok.clone()));
if let Some((pos, tok)) = n {
Some(Ok((pos, tok, pos)))
} else {
None
}
}
}
impl<'input> Lexer<'input> {
pub(crate) fn from_tokens(raw: &'input [Token]) -> Self {
Lexer {
iter: Box::new(raw.iter().enumerate())
}
}
}