Writing a Markdown Parser Part 1. Lexing

struct Position {
  line: usize;
  column: usize;
}

enum Token {
  eof,
  illegal
}

struct Lexer<'a> {
  source: Peekable<Chars<'a>>;
}

impl<'a> Lexer<'a> {
  fn new(src: &str) {
    let source = src.chars();

    Lexer { source }
  }
}

impl<'a> Iterator for Lexer<'a> {
  type Item = (Token, Position);

  fn next(&mut self) -> Self::Item {
    match self.source.peek() {
      Some(_) => None,
      None => None,
    }
  }
}

Go

package lexer

type Lexer struct{
  Source
}

func NewLexer(input str) *Lexer {
  source := bufio.NewReader(input)
  return &Lexer{
    Source: source
  }
}