}
/// match on a string prefix, and bind the remainder to an identifier
// TODO allow prefix-binding-suffix and binding-suffix as well.
// No plans for infix strings, that would add ambiguity as well
// as complicating the parser.
// TODO Making this a TT muncher would simplify parsing and make it
// easier to make new cases
macro_rules! match_str {
    (($name:ident) $($s:expr , $rem:ident => $body:expr ,)* _ => $else:expr) => {
        $(if $name.starts_with($s) {
            let $rem = &$name[$s.len()..];
            $body
        } else)* {$else}
    };

        // TODO make a macro that matches on e.g. `"pre":x => {}` and desugars to
        // the kind of slice below
        if line.starts_with("```") {
            // ignore anything after the lead chars on preformat lines
            return RawLine::Toggle {
                alt: TextLine(&line[3..]),
            };
        } else if line.starts_with("=> ") {
            let line = &line[3..];
            match line.split_once(' ') {
                Some((url, desc)) => {
                    let url = url.trim_start_matches(' ');
                    Line::Link {
                        url: TextLine(url),
                        description: Some(TextLine(desc)),

        match_str! {(line)
            "```", rem => {
                // ignore anything after the lead chars on preformat lines
                return RawLine::Toggle {
                    alt: TextLine(rem),
                }
            },
            "=> ", rem => {
                match rem.split_once(' ') {
                    Some((url, desc)) => {
                        let url = url.trim_start_matches(' ');
                        Line::Link {
                            url: TextLine(url),
                            description: Some(TextLine(desc)),
                        }

                    None => Line::Link {
                        url: TextLine(rem),
                        description: None,
                    },

                None => Line::Link {
                    url: TextLine(line),
                    description: None,
                },

            },
            "* ", rem => {
                Line::ListItem(TextLine(rem))
            },
            "# ", rem => {
                Line::Heading {
                    level: 1,
                    title: TextLine(rem),
                }
            },
            "## ", rem => {
                Line::Heading {
                    level: 2,
                    title: TextLine(rem),
                }
            },
            "### ", rem => {
                Line::Heading {
                    level: 3,
                    title: TextLine(rem),
                }
            },
            ">", rem => {
                Line::Quote(TextLine(rem))
            },
            _ => {
                Line::Text(TextLine(line))

        } else if line.starts_with("* ") {
            Line::ListItem(TextLine(&line[2..]))
        } else if line.starts_with("# ") {
            Line::Heading {
                level: 1,
                title: TextLine(&line[2..]),
            }
        } else if line.starts_with("## ") {
            Line::Heading {
                level: 2,
                title: TextLine(&line[3..]),
            }
        } else if line.starts_with("### ") {
            Line::Heading {
                level: 3,
                title: TextLine(&line[4..]),
            }
        } else if line.starts_with(">") {
            Line::Quote(TextLine(&line[1..]))
        } else {
            Line::Text(string)