wip

src/block.rs

@@ -7,6 +7,7 @@ use Container::*;
 use Leaf::*;
 
 pub type Tree = tree::Tree<Block, Atom>;
+pub type TreeIter<'t> = tree::Iter<'t, Block, Atom>;
 
 pub fn parse(src: &str) -> Tree {
     Parser::new(src).parse()

src/inline.rs

@@ -1,40 +1,43 @@
 use crate::Span;
 
 use crate::tree;
+use crate::CowStr;
 
 use Atom::*;
 use Container::*;
 
-pub type Tree = tree::Tree<Container, Atom>;
+pub type Tree<'s> = tree::Tree<Container, Atom<'s>>;
 
-pub fn parse<I: Iterator<Item = Span>>(src: &str, inlines: I) -> Tree {
+/*
+pub fn parse<'s, I: Iterator<Item = Span>>(src: &'s str, inlines: I) -> Vec<Event<'s>> {
     Parser::new(src).parse(inlines)
 }
+*/
 
-pub enum Inline {
-    Atom(Atom),
+pub enum Inline<'s> {
+    Atom(Atom<'s>),
     Container(Container),
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
-pub enum Atom {
+pub enum Atom<'s> {
     Str,
     Softbreak,
     Hardbreak,
     Escape,
-    Nbsp,
-    FootnoteReference,
-    ExplicitLink,
-    ReferenceLink,
-    Emoji,
-    OpenMarker,
-    Ellipses,
-    ImageMarker,
-    EmDash,
-    RawFormat,
+    Nbsp,        // ??
+    OpenMarker,  // ??
+    Ellipses,    // ??
+    ImageMarker, // ??
+    EmDash,      // ??
+    FootnoteReference { label: CowStr<'s> },
+    ExplicitLink { label: CowStr<'s> },
+    ReferenceLink { label: CowStr<'s> },
+    Emoji { name: CowStr<'s> },
+    RawFormat { format: CowStr<'s> },
 }
 
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
 pub enum Container {
     // attributes
     Attributes,
@@ -63,25 +66,148 @@ pub enum Container {
     Destination,
 }
 
-pub struct Event;
+#[derive(Debug)]
+pub enum Event<'s> {
+    Start(Container, OpenerState),
+    End(Container),
+    Atom(Atom<'s>),
+}
 
-pub struct Parser<'s> {
-    src: &'s str,
+#[derive(Debug)]
+pub enum OpenerState {
+    Unclosed,
+    Closed,
+    Discarded,
+}
+
+#[derive(Debug)]
+pub enum ContainerType {
+    Opener,
+    Closer,
+    Both,
+}
+
+pub struct Parser<'s, I: Iterator<Item = char>> {
+    chars: std::iter::Peekable<I>,
     openers: Vec<(Container, usize)>,
-    events: Vec<(Event, Span)>,
+    events: Vec<Event<'s>>,
     //tree: tree::Builder<Container, Atom>,
 }
 
-impl<'s> Parser<'s> {
-    fn new(src: &'s str) -> Self {
+impl<'s, I: Iterator<Item = char>> Parser<'s, I> {
+    pub fn new(chars: I) -> Self {
         Self {
-            src,
+            chars: chars.peekable(),
             openers: Vec::new(),
             events: Vec::new(),
         }
     }
 
-    fn parse<I: Iterator<Item = Span>>(mut self, inlines: I) -> Tree {
+    /*
+    fn step(&mut self) -> lex::Token {
+        let token = lex::Lexer::new(&self.src[self.pos..]).next_token();
+        self.pos += token.len;
+        std::mem::replace(&mut self.next_token, token)
+    }
+
+    fn eat(&mut self) -> lex::TokenKind {
+        loop {
+            let end = self.pos;
+            let token = self.step();
+            if !matches!(token.kind, lex::TokenKind::Whitespace) {
+                self.span = Span::new(end - token.len, end);
+                return token.kind;
+            }
+        }
+    }
+
+    fn peek(&mut self) -> &lex::TokenKind {
+        if matches!(self.next_token.kind, lex::TokenKind::Whitespace) {
+            let _whitespace = self.step();
+        }
+        &self.next_token.kind
+    }
+    */
+
+    pub fn parse(mut self) -> Vec<(Event<'s>, u32)> {
+        let mut len = 0;
+
+        while let Some(c) = self.chars.peek() {
+            //let start = self.pos();
+
+            let cont = match c {
+                '*' => Some((Strong, ContainerType::Both)),
+                '_' => Some((Emph, ContainerType::Both)),
+                '^' => Some((Superscript, ContainerType::Both)),
+                '~' => Some((Subscript, ContainerType::Both)),
+                '\'' => Some((SingleQuoted, ContainerType::Both)),
+                '"' => Some((DoubleQuoted, ContainerType::Both)),
+                '`' => todo!(),
+                '{' => todo!(),
+                '$' => todo!(),
+                '<' => todo!(),
+                '[' => todo!(),
+                _ => None,
+            };
+
+            let ev = cont
+                .and_then(|(cont, ty)| {
+                    self.openers
+                        .iter()
+                        .rposition(|(c, _)| *c == cont)
+                        .map(|i| {
+                            if let Event::Start(c, state) = &mut self.events[i] {
+                                assert_eq!(*c, cont);
+                                if matches!(ty, ContainerType::Closer | ContainerType::Both) {
+                                    *state = OpenerState::Closed;
+                                    Some(Event::End(cont))
+                                } else if matches!(ty, ContainerType::Opener | ContainerType::Both)
+                                {
+                                    *state = OpenerState::Discarded;
+                                    Some(Event::Start(cont, OpenerState::Unclosed))
+                                } else {
+                                    None
+                                }
+                            } else {
+                                unreachable!()
+                            }
+                        })
+                        .unwrap_or_else(|| {
+                            matches!(ty, ContainerType::Opener | ContainerType::Both).then(|| {
+                                self.openers.push((cont, self.events.len()));
+                                Event::Start(cont, OpenerState::Unclosed)
+                            })
+                        })
+                })
+                .unwrap_or(Event::Atom(Str));
+
+            self.events.push(ev);
+        }
+        //self.events
         todo!()
     }
 }
+
+/*
+impl<'s> Iterator for Parser<'s> {
+    type Item = (Event<'s>, Span);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.chars.next().map(|c| {
+            match c {
+                '*' => todo!(),
+                '_' => todo!(),
+                '^' => todo!(),
+                '~' => todo!(),
+                '\'' => todo!(),
+                '"' => todo!(),
+                '$' => todo!(),
+                '<' => todo!(),
+                '{' => todo!(),
+                '[' => todo!(),
+                _ =>
+            }
+        })
+    }
+}
+*/

src/lex.rs

@@ -0,0 +1,358 @@
+use crate::EOF;
+
+use Delimiter::*;
+use Sequence::*;
+use Symbol::*;
+use TokenKind::*;
+
+#[derive(Debug)]
+pub(crate) struct Token {
+    pub kind: TokenKind,
+    pub len: usize,
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum TokenKind {
+    Text,
+    Whitespace,
+    Nbsp,
+    Escape,
+    Integer,
+    Open(Delimiter),
+    Close(Delimiter),
+    Sym(Symbol),
+    Seq(Sequence),
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum Delimiter {
+    Brace,
+    BraceAsterisk,
+    BraceCaret,
+    BraceEqual,
+    BraceHyphen,
+    BracePlus,
+    BraceTilde,
+    BraceUnderscore,
+    Bracket,
+    Paren,
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum Symbol {
+    Asterisk,
+    Caret,
+    Dollar1,
+    Dollar2,
+    Equal,
+    Exclaim,
+    Gt,
+    Lt,
+    Percentage,
+    Pipe,
+    Plus,
+    Quote1,
+    Quote2,
+    Tilde,
+    Underscore,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum Sequence {
+    Backtick,
+    Colon,
+    Hash,
+    Hyphen,
+    Period,
+}
+
+impl Sequence {
+    fn ch(self) -> char {
+        match self {
+            Self::Backtick => '`',
+            Self::Colon => ':',
+            Self::Hash => '#',
+            Self::Period => '.',
+            Self::Hyphen => '-',
+        }
+    }
+}
+
+pub(crate) struct Lexer<I: Iterator<Item = char>> {
+    chars: std::iter::Peekable<I>,
+    escape: bool,
+    next: Option<Token>,
+    len: usize,
+}
+
+impl<I: Iterator<Item = char>> Lexer<I> {
+    pub fn new(chars: I) -> Lexer<I> {
+        Lexer {
+            chars: chars.peekable(),
+            escape: false,
+            next: None,
+            len: 0,
+        }
+    }
+
+    fn peek(&mut self) -> char {
+        self.chars.peek().copied().unwrap_or(EOF)
+    }
+
+    fn eat(&mut self) -> Option<char> {
+        let c = self.chars.next();
+        self.len += c.map_or(0, char::len_utf8);
+        c
+    }
+
+    fn len(&self) -> usize {
+        self.len
+    }
+
+    fn eat_while(&mut self, mut predicate: impl FnMut(char) -> bool) {
+        while predicate(self.peek()) {
+            self.eat();
+        }
+    }
+
+    fn token(&mut self) -> Option<Token> {
+        let first = self.eat()?;
+
+        let escape = self.escape;
+
+        let kind = match first {
+            _ if escape && first == ' ' => Nbsp,
+            _ if escape => Text,
+
+            '\\' => {
+                let next = self.peek();
+                if next == ' ' || next.is_ascii_punctuation() {
+                    self.escape = true;
+                    Escape
+                } else {
+                    Text
+                }
+            }
+
+            _ if first.is_whitespace() => {
+                self.eat_while(char::is_whitespace);
+                Whitespace
+            }
+
+            '(' => Open(Paren),
+            ')' => Close(Paren),
+            '[' => Open(Bracket),
+            ']' => Close(Bracket),
+            '{' => {
+                let explicit = match self.peek() {
+                    '*' => Some(Open(BraceAsterisk)),
+                    '^' => Some(Open(BraceCaret)),
+                    '=' => Some(Open(BraceEqual)),
+                    '-' => Some(Open(BraceHyphen)),
+                    '+' => Some(Open(BracePlus)),
+                    '~' => Some(Open(BraceTilde)),
+                    '_' => Some(Open(BraceUnderscore)),
+                    _ => None,
+                };
+                if let Some(exp) = explicit {
+                    self.eat();
+                    exp
+                } else {
+                    Open(Brace)
+                }
+            }
+            '*' => self.maybe_eat_close_brace(Asterisk, BraceAsterisk),
+            '^' => self.maybe_eat_close_brace(Caret, BraceCaret),
+            '=' => self.maybe_eat_close_brace(Equal, BraceEqual),
+            '+' => self.maybe_eat_close_brace(Plus, BracePlus),
+            '~' => self.maybe_eat_close_brace(Tilde, BraceTilde),
+            '_' => self.maybe_eat_close_brace(Underscore, BraceUnderscore),
+            '-' => {
+                if self.peek() == '}' {
+                    self.eat();
+                    Close(BraceHyphen)
+                } else {
+                    self.eat_seq(Hyphen)
+                }
+            }
+
+            '$' => {
+                if self.peek() == '$' {
+                    self.eat();
+                    Sym(Dollar2)
+                } else {
+                    Sym(Dollar1)
+                }
+            }
+            '!' => Sym(Exclaim),
+            '%' => Sym(Percentage),
+            '<' => Sym(Lt),
+            '>' => Sym(Gt),
+            '|' => Sym(Pipe),
+            '\'' => Sym(Quote1),
+            '"' => Sym(Quote2),
+
+            '`' => self.eat_seq(Backtick),
+            ':' => self.eat_seq(Colon),
+            '#' => self.eat_seq(Hash),
+            '.' => self.eat_seq(Period),
+
+            '0'..='9' => {
+                self.eat_while(|c| c.is_ascii_digit());
+                Integer
+            }
+
+            _ => Text,
+        };
+
+        if escape {
+            self.escape = false;
+        }
+
+        let len = self.len();
+
+        Some(Token { kind, len })
+    }
+
+    fn eat_seq(&mut self, s: Sequence) -> TokenKind {
+        self.eat_while(|c| c == s.ch());
+        Seq(s)
+    }
+
+    fn maybe_eat_close_brace(&mut self, s: Symbol, d: Delimiter) -> TokenKind {
+        if self.peek() == '}' {
+            self.eat();
+            Close(d)
+        } else {
+            Sym(s)
+        }
+    }
+}
+
+impl<I: Iterator<Item = char>> Iterator for Lexer<I> {
+    type Item = Token;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if let Some(token) = self.next.take() {
+            Some(token)
+        } else {
+            let mut current = self.token();
+
+            // concatenate text tokens
+            if let Some(Token { kind: Text, len }) = &mut current {
+                self.next = self.token();
+                while let Some(Token { kind: Text, len: l }) = self.next {
+                    *len += l;
+                    self.next = self.token();
+                }
+            }
+
+            current
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::Delimiter::*;
+    use super::Sequence::*;
+    use super::Symbol::*;
+    use super::TokenKind::*;
+
+    macro_rules! test_lex {
+        ($($st:ident,)? $src:expr $(,$($token:expr),* $(,)?)?) => {
+            #[allow(unused)]
+            let actual = super::Lexer::new($src.chars()).map(|t| t.kind).collect::<Vec<_>>();
+            let expected = vec![$($($token),*,)?];
+            assert_eq!(actual, expected, "{}", $src);
+        };
+    }
+
+    #[test]
+    fn empty() {
+        test_lex!("");
+    }
+
+    #[test]
+    fn basic() {
+        test_lex!("abc", Text);
+        test_lex!(
+            "para w/ some _emphasis_ and *strong*.",
+            Text,
+            Whitespace,
+            Text,
+            Whitespace,
+            Text,
+            Whitespace,
+            Sym(Underscore),
+            Text,
+            Sym(Underscore),
+            Whitespace,
+            Text,
+            Whitespace,
+            Sym(Asterisk),
+            Text,
+            Sym(Asterisk),
+            Seq(Period)
+        );
+    }
+
+    #[test]
+    fn escape() {
+        test_lex!(r#"\a"#, Text);
+        test_lex!(r#"\\a"#, Escape, Text);
+        test_lex!(r#"\."#, Escape, Text);
+        test_lex!(r#"\ "#, Escape, Nbsp);
+        test_lex!(r#"\{-"#, Escape, Text, Seq(Hyphen));
+    }
+
+    #[test]
+    fn delim() {
+        test_lex!("{-", Open(BraceHyphen));
+        test_lex!("-}", Close(BraceHyphen));
+        test_lex!("{++}", Open(BracePlus), Close(BracePlus));
+    }
+
+    #[test]
+    fn sym() {
+        test_lex!(
+            r#"'*^=!><%|+"~_"#,
+            Sym(Quote1),
+            Sym(Asterisk),
+            Sym(Caret),
+            Sym(Equal),
+            Sym(Exclaim),
+            Sym(Gt),
+            Sym(Lt),
+            Sym(Percentage),
+            Sym(Pipe),
+            Sym(Plus),
+            Sym(Quote2),
+            Sym(Tilde),
+            Sym(Underscore),
+        );
+        test_lex!("''''", Sym(Quote1), Sym(Quote1), Sym(Quote1), Sym(Quote1),);
+    }
+
+    #[test]
+    fn seq() {
+        test_lex!("`", Seq(Backtick));
+        test_lex!("```", Seq(Backtick));
+        test_lex!(
+            "`:#-.",
+            Seq(Backtick),
+            Seq(Colon),
+            Seq(Hash),
+            Seq(Hyphen),
+            Seq(Period),
+        );
+    }
+
+    #[test]
+    fn int() {
+        test_lex!("1", Integer);
+        test_lex!("123", Integer);
+        test_lex!("1234567890", Integer);
+        test_lex!("000", Integer);
+    }
+}

src/lib.rs

@@ -1,11 +1,110 @@
 mod block;
 mod inline;
+mod lex;
 mod span;
 mod tree;
 
-pub use block::parse;
-pub use block::Tree;
+use inline::Atom;
+use inline::Container as InlineTag;
+
+pub struct Block;
 
 const EOF: char = '\0';
 
+type CowStr<'s> = std::borrow::Cow<'s, str>;
+
+/*
+pub enum Tag<'s> {
+    Paragraph,
+    Heading { level: u8 },
+    BlockQuote,
+    CodeBlock { info_string: CowStr<'s> },
+    List { start_index: Option<u64> },
+    ListItem,
+    FootnoteDefinition { label: CowStr<'s> },
+    Table,
+    Image {},
+    Link {},
+    Block(Block),
+    Inline(InlineTag),
+}
+
+pub struct Attributes; // TODO
+
+pub enum Event<'s> {
+    Start(Tag<'s>, Attributes),
+    End(Tag<'s>),
+    Atom(Atom<'s>),
+}
+*/
+
 use span::Span;
+
+pub struct Parser<'s> {
+    src: &'s str,
+    tree: block::Tree,
+}
+
+impl<'s> Parser<'s> {
+    pub fn new(src: &'s str) -> Self {
+        Self {
+            src,
+            tree: block::parse(src),
+        }
+    }
+
+    pub fn parse(&mut self) {}
+
+    pub fn iter(&self) -> Iter {
+        Iter {
+            src: self.src,
+            tree: self.tree.iter().peekable(),
+        }
+    }
+}
+
+pub struct Iter<'s> {
+    src: &'s str,
+    tree: std::iter::Peekable<block::TreeIter<'s>>,
+}
+
+impl<'s> Iterator for Iter<'s> {
+    type Item = String;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.tree.next().map(|ev| match ev {
+            tree::Event::Enter(block::Block::Container(cont), _sp) => {
+                format!("cont {:?}", cont)
+            }
+            tree::Event::Enter(block::Block::Leaf(leaf), _sp) => {
+                // concatenate all inlines
+                let chars = (&mut self.tree)
+                    .take_while(|ev| matches!(ev, tree::Event::Element(..)))
+                    .flat_map(|ev| ev.span().of(self.src).chars());
+                let evs = inline::Parser::new(chars).parse();
+                /*
+                let chars = std::iter::from_fn(|| {
+                    let mut eat = false;
+                    let ret = if let Some(tree::Event::Element(_a, sp)) = self.tree.peek() {
+                        eat = true;
+                        let chars = sp.of(self.src).chars();
+                        Some(chars)
+                    } else {
+                        None
+                    };
+                    if eat {
+                        self.tree.next();
+                    }
+                    ret
+                })
+                .flatten();
+                */
+                format!("leaf {:?} {:?}", leaf, evs)
+            }
+            tree::Event::Element(atom, _sp) => {
+                format!("atom {:?}", atom)
+            }
+            tree::Event::Exit => "exit".to_string(),
+        })
+    }
+}

src/main.rs

@@ -6,5 +6,7 @@ fn main() {
         .read_to_string(&mut src)
         .expect("failed to read unicode file");
 
-    print!("{}", jotdown::parse(&src));
+    let p = jotdown::Parser::new(&src);
+    let v = p.iter().collect::<Vec<_>>();
+    print!("{:?}", v);
 }

src/tree.rs

@@ -22,6 +22,15 @@ pub enum Event<'a, C, E> {
     Exit,
 }
 
+impl<'a, C, E> Event<'a, C, E> {
+    pub fn span(&self) -> Span {
+        match self {
+            Self::Enter(_, sp) | Self::Element(_, sp) => *sp,
+            Self::Exit => panic!(),
+        }
+    }
+}
+
 pub struct Iter<'a, C, E> {
     nodes: &'a [Node<C, E>],
     branch: Vec<NodeIndex>,