Add basic support for block quotes

3 files changed, 447 insertions, 47 deletions

diff --git a/src/content/document.rs b/src/content/document.rs
new file mode 100644
index 0000000..dd5038f
--- /dev/null
+++ b/src/content/document.rs
@@ -0,0 +1,439 @@
+//! The document content type.
+//!
+//! **Document** represents the containers, such as block quotes and lists,
+//! which structure the document and contain other sections.
+//!
+//! The constructs found in flow are:
+//!
+//! *   [Block quote][crate::construct::block_quote]
+//! *   List
+
+use crate::construct::block_quote::{
+    cont as block_quote_cont, end as block_quote_end, start as block_quote,
+};
+use crate::content::flow::start as flow;
+use crate::parser::ParseState;
+use crate::subtokenize::subtokenize;
+use crate::tokenizer::{
+    Code, Event, EventType, Point, State, StateFn, StateFnResult, TokenType, Tokenizer,
+};
+use crate::util::edit_map::EditMap;
+use crate::util::{
+    normalize_identifier::normalize_identifier,
+    span::{from_exit_event, serialize},
+};
+use std::collections::HashSet;
+
+struct DocumentInfo {
+    continued: usize,
+    stack: Vec<String>,
+    next: Box<StateFn>,
+    last_line_ending_index: Option<usize>,
+    map: EditMap,
+}
+
+/// Turn `codes` as the document content type into events.
+pub fn document(parse_state: &mut ParseState, point: Point, index: usize) -> Vec<Event> {
+    let mut tokenizer = Tokenizer::new(point, index, parse_state);
+
+    tokenizer.push(&parse_state.codes, Box::new(start), true);
+
+    let mut index = 0;
+    let mut next_definitions: HashSet<String> = HashSet::new();
+
+    while index < tokenizer.events.len() {
+        let event = &tokenizer.events[index];
+
+        if event.event_type == EventType::Exit
+            && event.token_type == TokenType::DefinitionLabelString
+        {
+            next_definitions.insert(normalize_identifier(
+                serialize(
+                    &parse_state.codes,
+                    &from_exit_event(&tokenizer.events, index),
+                    false,
+                )
+                .as_str(),
+            ));
+        }
+
+        index += 1;
+    }
+
+    let mut result = (tokenizer.events, false);
+
+    parse_state.definitions = next_definitions;
+
+    while !result.1 {
+        result = subtokenize(result.0, parse_state);
+    }
+
+    result.0
+}
+
+fn start(tokenizer: &mut Tokenizer, code: Code) -> StateFnResult {
+    let info = DocumentInfo {
+        continued: 0,
+        stack: vec![],
+        next: Box::new(flow),
+        last_line_ending_index: None,
+        map: EditMap::new(),
+    };
+    before(tokenizer, code, info)
+}
+
+fn before(tokenizer: &mut Tokenizer, code: Code, info: DocumentInfo) -> StateFnResult {
+    println!("before: check existing open containers");
+    // First we iterate through the open blocks, starting with the root
+    // document, and descending through last children down to the last open
+    // block.
+    // Each block imposes a condition that the line must satisfy if the block
+    // is to remain open.
+    // For example, a block quote requires a `>` character.
+    // A paragraph requires a non-blank line.
+    // In this phase we may match all or just some of the open blocks.
+    // But we cannot close unmatched blocks yet, because we may have a lazy
+    // continuation line.
+    if info.continued < info.stack.len() {
+        let name = &info.stack[info.continued];
+        // To do: list.
+        let cont = if name == "blockquote" {
+            block_quote_cont
+        } else {
+            unreachable!("todo: cont construct {:?}", name)
+        };
+
+        // To do: state?
+
+        tokenizer.attempt(cont, move |ok| {
+            if ok {
+                Box::new(|t, c| document_continue(t, c, info))
+            } else {
+                Box::new(|t, c| check_new_containers(t, c, info))
+            }
+        })(tokenizer, code)
+    } else {
+        // Done.
+        check_new_containers(tokenizer, code, info)
+    }
+}
+
+fn document_continue(
+    tokenizer: &mut Tokenizer,
+    code: Code,
+    mut info: DocumentInfo,
+) -> StateFnResult {
+    println!("document_continue");
+    info.continued += 1;
+
+    println!("  to do: close flow sometimes?");
+    // // Note: this field is called `_closeFlow` but it also closes containers.
+    // // Perhaps a good idea to rename it but it’s already used in the wild by
+    // // extensions.
+    // if (self.containerState._closeFlow) {
+    //   self.containerState._closeFlow = undefined
+
+    //   if (childFlow) {
+    //     closeFlow()
+    //   }
+
+    //   // Note: this algorithm for moving events around is similar to the
+    //   // algorithm when dealing with lazy lines in `writeToChild`.
+    //   const indexBeforeExits = self.events.length
+    //   let indexBeforeFlow = indexBeforeExits
+    //   /** @type {Point|undefined} */
+    //   let point
+
+    //   // Find the flow chunk.
+    //   while (indexBeforeFlow--) {
+    //     if (
+    //       self.events[indexBeforeFlow][0] === 'exit' &&
+    //       self.events[indexBeforeFlow][1].type === types.chunkFlow
+    //     ) {
+    //       point = self.events[indexBeforeFlow][1].end
+    //       break
+    //     }
+    //   }
+
+    //   assert(point, 'could not find previous flow chunk')
+
+    let size = info.continued;
+    exit_containers(tokenizer, &mut info, size);
+
+    //   // Fix positions.
+    //   let index = indexBeforeExits
+
+    //   while (index < self.events.length) {
+    //     self.events[index][1].end = Object.assign({}, point)
+    //     index++
+    //   }
+
+    //   // Inject the exits earlier (they’re still also at the end).
+    //   splice(
+    //     self.events,
+    //     indexBeforeFlow + 1,
+    //     0,
+    //     self.events.slice(indexBeforeExits)
+    //   )
+
+    //   // Discard the duplicate exits.
+    //   self.events.length = index
+
+    //   return checkNewContainers(code)
+    // }
+
+    before(tokenizer, code, info)
+}
+// documentContinue
+
+fn check_new_containers(
+    tokenizer: &mut Tokenizer,
+    code: Code,
+    info: DocumentInfo,
+) -> StateFnResult {
+    println!("check_new_containers");
+    // Next, after consuming the continuation markers for existing blocks, we
+    // look for new block starts (e.g. `>` for a block quote).
+    // If we encounter a new block start, we close any blocks unmatched in
+    // step 1 before creating the new block as a child of the last matched
+    // block.
+    if info.continued == info.stack.len() {
+        println!("  to do: concrete? interrupt?");
+        //   // No need to `check` whether there’s a container, of `exitContainers`
+        //   // would be moot.
+        //   // We can instead immediately `attempt` to parse one.
+        //   if (!childFlow) {
+        //     return documentContinued(code)
+        //   }
+
+        //   // If we have concrete content, such as block HTML or fenced code,
+        //   // we can’t have containers “pierce” into them, so we can immediately
+        //   // start.
+        //   if (childFlow.currentConstruct && childFlow.currentConstruct.concrete) {
+        //     return flowStart(code)
+        //   }
+
+        //   // If we do have flow, it could still be a blank line,
+        //   // but we’d be interrupting it w/ a new container if there’s a current
+        //   // construct.
+        //   self.interrupt = Boolean(
+        //     childFlow.currentConstruct && !childFlow._gfmTableDynamicInterruptHack
+        //   )
+    }
+
+    // Check if there is a new container.
+    // To do: list.
+    tokenizer.attempt(block_quote, move |ok| {
+        if ok {
+            Box::new(|t, c| there_is_a_new_container(t, c, info, "blockquote".to_string()))
+        } else {
+            Box::new(|t, c| there_is_no_new_container(t, c, info))
+        }
+    })(tokenizer, code)
+}
+
+fn there_is_a_new_container(
+    tokenizer: &mut Tokenizer,
+    code: Code,
+    mut info: DocumentInfo,
+    name: String,
+) -> StateFnResult {
+    println!("there_is_a_new_container");
+    println!("  todo: close_flow");
+    // if (childFlow) closeFlow()
+    let size = info.continued;
+    exit_containers(tokenizer, &mut info, size);
+    info.stack.push(name);
+    info.continued += 1;
+    document_continued(tokenizer, code, info)
+}
+
+/// Exit open containers.
+fn exit_containers(tokenizer: &mut Tokenizer, info: &mut DocumentInfo, size: usize) {
+    while info.stack.len() > size {
+        let name = info.stack.pop().unwrap();
+
+        // To do: list.
+        let end = if name == "blockquote" {
+            block_quote_end
+        } else {
+            unreachable!("todo: cont {:?}", name)
+        };
+
+        // To do: improve below code.
+        let insert_index = if let Some(index) = info.last_line_ending_index {
+            index
+        } else {
+            tokenizer.events.len()
+        };
+        let eol_point = if let Some(index) = info.last_line_ending_index {
+            tokenizer.events[index].point.clone()
+        } else {
+            tokenizer.point.clone()
+        };
+        let eol_index = if let Some(index) = info.last_line_ending_index {
+            tokenizer.events[index].index
+        } else {
+            tokenizer.index
+        };
+
+        let token_types = end();
+
+        let mut index = 0;
+        while index < token_types.len() {
+            let token_type = &token_types[index];
+
+            info.map.add(
+                insert_index,
+                0,
+                vec![Event {
+                    event_type: EventType::Exit,
+                    token_type: token_type.clone(),
+                    point: eol_point.clone(),
+                    index: eol_index,
+                    previous: None,
+                    next: None,
+                    content_type: None,
+                }],
+            );
+
+            let mut stack_index = tokenizer.stack.len();
+
+            while stack_index > 0 {
+                stack_index -= 1;
+
+                if tokenizer.stack[stack_index] == *token_type {
+                    break;
+                }
+            }
+
+            assert_eq!(
+                tokenizer.stack[stack_index], *token_type,
+                "expected token type"
+            );
+            tokenizer.stack.remove(stack_index);
+
+            index += 1;
+        }
+    }
+}
+
+fn there_is_no_new_container(
+    tokenizer: &mut Tokenizer,
+    code: Code,
+    info: DocumentInfo,
+) -> StateFnResult {
+    let lazy = info.continued != info.stack.len();
+    tokenizer.lazy = lazy;
+    println!("there is no new container");
+    if lazy {
+        println!(
+            "  This line will be lazy. Depending on what is parsed now, we need to close containers before?"
+        );
+    }
+    // lineStartOffset = self.now().offset
+    flow_start(tokenizer, code, info)
+}
+
+fn document_continued(tokenizer: &mut Tokenizer, code: Code, info: DocumentInfo) -> StateFnResult {
+    println!("document_continued");
+
+    // Try new containers.
+    // To do: list.
+    tokenizer.attempt(block_quote, |ok| {
+        if ok {
+            Box::new(|t, c| container_continue(t, c, info))
+        } else {
+            Box::new(|t, c| {
+                // To do: this looks like a bug?
+                t.lazy = false;
+                flow_start(t, c, info)
+            })
+        }
+    })(tokenizer, code)
+}
+
+fn container_continue(
+    tokenizer: &mut Tokenizer,
+    code: Code,
+    mut info: DocumentInfo,
+) -> StateFnResult {
+    println!("container_continue");
+    // assert(
+    //   self.currentConstruct,
+    //   'expected `currentConstruct` to be defined on tokenizer'
+    // )
+    // assert(
+    //   self.containerState,
+    //   'expected `containerState` to be defined on tokenizer'
+    // )
+    info.continued += 1;
+    // To do: add to stack?
+    // stack.push([self.currentConstruct, self.containerState])
+    // Try another.
+    document_continued(tokenizer, code, info)
+}
+
+fn flow_start(tokenizer: &mut Tokenizer, code: Code, mut info: DocumentInfo) -> StateFnResult {
+    println!("flow_start");
+    let next = info.next;
+    info.next = Box::new(flow); // This is weird but Rust needs a function there.
+
+    let size = info.continued;
+    exit_containers(tokenizer, &mut info, size);
+
+    tokenizer.go_until(next, eof_eol, move |(state, remainder)| {
+        (
+            State::Fn(Box::new(move |t, c| flow_end(t, c, info, state))),
+            remainder,
+        )
+    })(tokenizer, code)
+}
+
+fn flow_end(
+    tokenizer: &mut Tokenizer,
+    code: Code,
+    mut info: DocumentInfo,
+    result: State,
+) -> StateFnResult {
+    println!("flow_end");
+    let was_lazy = tokenizer.lazy;
+
+    if was_lazy {
+        println!(
+            "this line was lazy. Depeding on what was parsed, we need to exit containers after it?"
+        );
+    }
+
+    info.continued = 0;
+
+    // To do: blank lines? Other things?
+    if tokenizer.events.len() > 2
+        && tokenizer.events[tokenizer.events.len() - 1].token_type == TokenType::LineEnding
+    {
+        info.last_line_ending_index = Some(tokenizer.events.len() - 2);
+    } else {
+        info.last_line_ending_index = None;
+    }
+
+    match result {
+        State::Ok => {
+            println!("State::Ok");
+            exit_containers(tokenizer, &mut info, 0);
+            tokenizer.events = info.map.consume(&mut tokenizer.events);
+            (State::Ok, Some(vec![code]))
+        }
+        State::Nok => unreachable!("handle nok in `flow`?"),
+        State::Fn(func) => {
+            info.next = func;
+            before(tokenizer, code, info)
+        }
+    }
+}
+
+fn eof_eol(code: Code) -> bool {
+    matches!(
+        code,
+        Code::None | Code::CarriageReturnLineFeed | Code::Char('\n' | '\r')
+    )
+}
diff --git a/src/content/flow.rs b/src/content/flow.rs
index 74c6a62..f406685 100644
--- a/src/content/flow.rs
+++ b/src/content/flow.rs
@@ -26,52 +26,7 @@ use crate::construct::{
     html_flow::start as html_flow, paragraph::start as paragraph,
     thematic_break::start as thematic_break,
 };
-use crate::parser::ParseState;
-use crate::subtokenize::subtokenize;
-use crate::tokenizer::{Code, Event, EventType, Point, State, StateFnResult, TokenType, Tokenizer};
-use crate::util::{
-    normalize_identifier::normalize_identifier,
-    span::{from_exit_event, serialize},
-};
-use std::collections::HashSet;
-
-/// Turn `codes` as the flow content type into events.
-pub fn flow(parse_state: &mut ParseState, point: Point, index: usize) -> Vec<Event> {
-    let mut tokenizer = Tokenizer::new(point, index, parse_state);
-    tokenizer.push(&parse_state.codes, Box::new(start), true);
-    let mut next_definitions: HashSet<String> = HashSet::new();
-
-    let mut index = 0;
-
-    while index < tokenizer.events.len() {
-        let event = &tokenizer.events[index];
-
-        if event.event_type == EventType::Exit
-            && event.token_type == TokenType::DefinitionLabelString
-        {
-            next_definitions.insert(normalize_identifier(
-                serialize(
-                    &parse_state.codes,
-                    &from_exit_event(&tokenizer.events, index),
-                    false,
-                )
-                .as_str(),
-            ));
-        }
-
-        index += 1;
-    }
-
-    let mut result = (tokenizer.events, false);
-
-    parse_state.definitions = next_definitions;
-
-    while !result.1 {
-        result = subtokenize(result.0, parse_state);
-    }
-
-    result.0
-}
+use crate::tokenizer::{Code, State, StateFnResult, TokenType, Tokenizer};
 
 /// Before flow.
 ///
@@ -83,7 +38,7 @@ pub fn flow(parse_state: &mut ParseState, point: Point, index: usize) -> Vec<Eve
 /// |    bravo
 /// |***
 /// ```
-fn start(tokenizer: &mut Tokenizer, code: Code) -> StateFnResult {
+pub fn start(tokenizer: &mut Tokenizer, code: Code) -> StateFnResult {
     match code {
         Code::None => (State::Ok, None),
         _ => tokenizer.attempt(blank_line, |ok| {
diff --git a/src/content/mod.rs b/src/content/mod.rs
index ae8ad83..af40cc0 100644
--- a/src/content/mod.rs
+++ b/src/content/mod.rs
@@ -1,5 +1,11 @@
 //! Content types found in markdown.
+//!
+//! *   [document][document]
+//! *   [flow][flow]
+//! *   [string][string]
+//! *   [text][text]
 
+pub mod document;
 pub mod flow;
 pub mod string;
 pub mod text;