1 files changed, 88 insertions, 0 deletions
diff --git a/parse_wiki_text/src/heading.rs b/parse_wiki_text/src/heading.rs
new file mode 100644
index 0000000..9c4d647
--- /dev/null
+++ b/parse_wiki_text/src/heading.rs
@@ -0,0 +1,88 @@
+// 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_heading_end(state: &mut crate::State) {
+    let mut end_position = state.scan_position;
+    loop {
+        match state.get_byte(end_position - 1) {
+            Some(b'\t') | Some(b' ') => end_position -= 1,
+            _ => break,
+        }
+    }
+    let open_node = state.stack.pop().unwrap();
+    if state.get_byte(end_position - 1) != Some(b'=') || end_position < open_node.start + 3 {
+        state.warnings.push(crate::Warning {
+            end: end_position,
+            message: crate::WarningMessage::InvalidHeadingSyntaxRewinding,
+            start: open_node.start,
+        });
+        state.rewind(open_node.nodes, open_node.start);
+        return;
+    }
+    let start_level = match open_node.type_ {
+        crate::OpenNodeType::Heading { level } => level,
+        _ => unreachable!(),
+    };
+    let mut end_level: u8 = 1;
+    while end_level < start_level
+        && end_position - end_level as usize > open_node.start + end_level as usize + 2
+        && state.get_byte(end_position - end_level as usize - 1) == Some(b'=')
+    {
+        end_level += 1;
+    }
+    let position = state.skip_whitespace_backwards(end_position - end_level as usize);
+    if end_level < start_level {
+        state.warnings.push(crate::Warning {
+            end: end_position,
+            message: crate::WarningMessage::UnexpectedHeadingLevelCorrecting,
+            start: open_node.start,
+        });
+        let inner_start_position = open_node.start + end_level as usize;
+        if match state.nodes.get_mut(0) {
+            None => {
+                state.flushed_position = inner_start_position;
+                false
+            }
+            Some(crate::Node::Text { end, start, value }) => {
+                *start = inner_start_position;
+                *value = &state.wiki_text[inner_start_position..*end];
+                false
+            }
+            Some(_) => true,
+        } {
+            let end = state.skip_whitespace_forwards(open_node.start + start_level as usize);
+            state.nodes.insert(
+                0,
+                crate::Node::Text {
+                    end,
+                    start: inner_start_position,
+                    value: &state.wiki_text[inner_start_position..end],
+                },
+            );
+        }
+    }
+    state.flush(position);
+    let nodes = std::mem::replace(&mut state.nodes, open_node.nodes);
+    state.nodes.push(crate::Node::Heading {
+        end: end_position,
+        level: end_level,
+        nodes,
+        start: open_node.start,
+    });
+    state.scan_position += 1;
+    state.skip_empty_lines();
+}
+
+pub fn parse_heading_start(state: &mut crate::State) {
+    let mut level = 1;
+    while state.get_byte(state.scan_position + level) == Some(b'=') && level < 6 {
+        level += 1;
+    }
+    let position = state.skip_whitespace_forwards(state.scan_position + level);
+    state.flushed_position = position;
+    state.push_open_node(
+        crate::OpenNodeType::Heading { level: level as u8 },
+        position,
+    );
+}