Initial extraction from Norganize1.0.0

1 files changed, 52 insertions, 0 deletions

diff --git a/Sources/NorgKit/Parsers/TaskScanner.swift b/Sources/NorgKit/Parsers/TaskScanner.swift
new file mode 100644
index 0000000..39c16b5
--- /dev/null
+++ b/Sources/NorgKit/Parsers/TaskScanner.swift
@@ -0,0 +1,52 @@
+import Foundation
+
+/// Scans Norg source for tasks and rewrites their status markers.
+/// Handy to extract TODOs quicker than the parser can.
+public enum TaskScanner {
+
+  private static let markers = ASCIIByteSet("*-~>$^:")
+
+  /// Extracts every task in `content`, attributing each to `fileURL`.
+  public static func scan(content: String, fileURL: URL) -> [NorgTask] {
+    var tasks: [NorgTask] = []
+    TextHelper.enumerateLines(in: content) { line, index in
+      if let task = task(in: line, fileURL: fileURL, line: index) {
+        tasks.append(task)
+      }
+    }
+    return tasks
+  }
+
+  /// Parses a single line into a task, if it carries a status extension.
+  public static func task(in raw: String, fileURL: URL, line: Int) -> NorgTask? {
+    task(in: raw[...], fileURL: fileURL, line: line)
+  }
+
+  /// Span-free fast path over a line slice.
+  static func task(in line: Substring, fileURL: URL, line index: Int) -> NorgTask? {
+    guard let m = DetachedModifier.parse(line, accepting: markers), let status = m.status else {
+      return nil
+    }
+    return NorgTask(
+      fileURL: fileURL,
+      line: index,
+      status: status,
+      text: NorgInlineParser.plainText(m.content)
+    )
+  }
+
+  /// Returns `content` with the status marker on `line` replaced by `status`,
+  /// or `nil` if the line carries no recognisable task marker. Line endings are
+  /// preserved, so a CRLF file round-trips unchanged.
+  public static func updatedContent(_ content: String, line index: Int, to status: TaskStatus)
+    -> String? {
+    guard let line = TextHelper.line(in: content, at: index),
+      let m = DetachedModifier.parse(line, accepting: markers),
+      let statusIndex = m.statusIndex
+    else { return nil }
+
+    var updated = content
+    updated.replaceSubrange(statusIndex...statusIndex, with: status.rawValue)
+    return updated
+  }
+}