1 files changed, 109 insertions, 0 deletions
diff --git a/parse_wiki_text/src/comment.rs b/parse_wiki_text/src/comment.rs
new file mode 100644
index 0000000..d933c17
--- /dev/null
+++ b/parse_wiki_text/src/comment.rs
@@ -0,0 +1,109 @@
+// Copyright 2019 Fredrik Portström <https://portstrom.com>
+// This is free software distributed under the terms specified in
+// the file LICENSE at the top-level directory of this distribution.
+
+pub fn parse_comment(state: &mut crate::State) {
+    let start_position = state.scan_position;
+    let mut position = start_position;
+    state.flush(position);
+    position += 4;
+    while let Some(character) = state.get_byte(position) {
+        match character {
+            b'-' if state.get_byte(position + 1) == Some(b'-')
+                && state.get_byte(position + 2) == Some(b'>') =>
+            {
+                position += 3;
+                break;
+            }
+            b'<' if state.get_byte(position + 1) == Some(b'/') => {
+                if parse_end_tag(state, start_position, position) {
+                    return;
+                }
+                position += 2;
+                continue;
+            }
+            _ => {}
+        }
+        position += 1;
+    }
+    state.flushed_position = position;
+    state.scan_position = position;
+    state.nodes.push(crate::Node::Comment {
+        end: state.scan_position,
+        start: start_position,
+    });
+}
+
+fn parse_end_tag(
+    state: &mut crate::State,
+    comment_start_position: usize,
+    tag_start_position: usize,
+) -> bool {
+    let tag_name_start_position = tag_start_position + 2;
+    let mut tag_name_end_position = tag_name_start_position;
+    let tag_end_position = loop {
+        match state.get_byte(tag_name_end_position) {
+            None | Some(b'/') | Some(b'<') => return false,
+            Some(b'\t') | Some(b'\n') | Some(b' ') => {
+                let tag_end_position = state.skip_whitespace_forwards(tag_name_end_position + 1);
+                match state.get_byte(tag_end_position) {
+                    Some(b'>') => break tag_end_position,
+                    _ => return false,
+                }
+            }
+            Some(b'>') => break tag_name_end_position,
+            _ => tag_name_end_position += 1,
+        }
+    } + 1;
+    let tag_name = &state.wiki_text[tag_name_start_position..tag_name_end_position];
+    let tag_name = if tag_name.as_bytes().iter().all(u8::is_ascii_lowercase) {
+        crate::Cow::Borrowed(tag_name)
+    } else {
+        tag_name.to_ascii_lowercase().into()
+    };
+    let mut matched_node_index = None;
+    for (open_node_index, open_node) in state.stack.iter().enumerate().rev() {
+        if let crate::OpenNodeType::Tag { name, .. } = &open_node.type_ {
+            if name == &tag_name {
+                matched_node_index = Some(open_node_index);
+                break;
+            }
+        }
+    }
+    match matched_node_index {
+        None => false,
+        Some(open_node_index) => {
+            if open_node_index < state.stack.len() - 1 {
+                state.warnings.push(crate::Warning {
+                    end: tag_end_position,
+                    message: crate::WarningMessage::MissingEndTagRewinding,
+                    start: tag_start_position,
+                });
+                state.stack.truncate(open_node_index + 2);
+                let open_node = state.stack.pop().unwrap();
+                state.rewind(open_node.nodes, open_node.start);
+            } else {
+                state.warnings.push(crate::Warning {
+                    end: tag_end_position,
+                    message: crate::WarningMessage::EndTagInComment,
+                    start: tag_start_position,
+                });
+                state.nodes.push(crate::Node::Comment {
+                    end: tag_start_position,
+                    start: comment_start_position,
+                });
+                let open_node = state.stack.pop().unwrap();
+                state.flushed_position = tag_end_position;
+                state.scan_position = state.flushed_position;
+                let nodes = std::mem::replace(&mut state.nodes, open_node.nodes);
+                state.nodes.push(crate::Node::Tag {
+                    end: state.scan_position,
+                    name: tag_name,
+                    nodes,
+                    start: open_node.start,
+                });
+            }
+            true
+        }
+    }
+}