Extract from Norganizer

1 files changed, 21 insertions, 0 deletions

diff --git a/Sources/NorgKeyboardToolbar/LineScanner.swift b/Sources/NorgKeyboardToolbar/LineScanner.swift
new file mode 100644
index 0000000..53d443d
--- /dev/null
+++ b/Sources/NorgKeyboardToolbar/LineScanner.swift
@@ -0,0 +1,21 @@
+import Foundation
+
+/// Tools to find the start and end of a line.
+enum LineScanner {
+
+  /// Given a current position in a character array, find the index of the
+  /// start of the line.
+  static func lineStart(in characters: [Character], at position: Int) -> Int {
+    var start = position
+    while start > 0, characters[start - 1] != "\n" { start -= 1 }
+    return start
+  }
+
+  /// Given a current position in a character array, find the index right
+  /// after the next newline or end of buffer.
+  static func lineEnd(in characters: [Character], at position: Int) -> Int {
+    var end = position
+    while end < characters.count, characters[end] != "\n" { end += 1 }
+    return end
+  }
+}