fix sources location

src/line/header.rs

@@ -0,0 +1,47 @@
+use gtk::glib::{GString, Regex, RegexCompileFlags, RegexMatchFlags};
+
+pub enum Level {
+    H1,
+    H2,
+    H3,
+}
+
+pub struct Header {
+    pub value: GString,
+    pub level: Level,
+}
+
+impl Header {
+    pub fn from(line: &str) -> Option<Self> {
+        // Parse line
+        let regex = Regex::split_simple(
+            r"^(#{1,3})\s*(.+)$",
+            line,
+            RegexCompileFlags::DEFAULT,
+            RegexMatchFlags::DEFAULT,
+        );
+
+        // Detect header level
+        let level = regex.get(1)?;
+
+        let level = match level.len() {
+            1 => Level::H1,
+            2 => Level::H2,
+            3 => Level::H3,
+            _ => return None,
+        };
+
+        // Detect header value
+        let value = regex.get(2)?;
+
+        if value.trim().is_empty() {
+            return None;
+        }
+
+        // Result
+        Some(Self {
+            level,
+            value: GString::from(value.as_str()),
+        })
+    }
+}