Create Hello world for macOS (#1)

components/other/other.swift

@@ -0,0 +1,70 @@
+import Foundation
+
+/// Decode a base64 string back into a regular string
+func otherBase64ToString(_ encoded: String) -> String {
+    guard
+        let data = Data(base64Encoded: encoded),
+        let str = String(data: data, encoding: .utf8)
+    else {
+        return ""
+    }
+    return str
+}
+
+/// Capitalize the first letter of a string
+func otherCapitalize(_ s: String) -> String {
+    guard let first = s.first else {
+        return s
+    }
+    return String(first).uppercased() + String(s.dropFirst())
+}
+
+/// Launch to wait for asynchrnous actions
+func otherLaunch() {
+    RunLoop.current.run()
+}
+
+/// Count leading spaces in a line
+func otherLineIndent(_ line: String) -> Int {
+    var count = 0
+    for ch in line {
+        if ch == " " {
+            count += 1
+        } else {
+            break
+        }
+    }
+    return count
+}
+
+/// Print to stderr
+func otherPrintStderr(_ txt: String) {
+    if let dat = "\(txt)\n".data(using: .utf8) {
+        FileHandle.standardError.write(dat)
+    }
+}
+
+/// Print each key/value processed by a controller into stderr
+func otherSetupConsoleLogging(
+    _ ctrl: DialectController,
+    _ prefix: String
+) {
+    ctrl.registerCallback { c -> Void in
+        let value = c.fieldAny(c.recentField)
+        let line = "ИГР \(prefix) k/v: '\(c.recentField)'/'\(value)'"
+        otherPrintStderr(line)
+    }
+}
+
+/// Write output text to a file
+func otherWriteFile(
+    _ path: String,
+    _ content: String
+) {
+    try? content.write(toFile: path, atomically: true, encoding: .utf8)
+}
+
+/// Terminate the main RunLoop
+func otherShutdown() {
+    exit(0)
+}