JavaScript Highlighter: disable debug prints by default

MongoView/Synax Highlighting/JavaScriptHighlighter.swift

@@ -27,6 +27,7 @@ class JavaScriptHighlighter {
     private var currentIndex: String.Index!
     private var indent = ""
     private(set) var tokens = [(token: TokenType, range: NSRange)]()
+    var debug = false
     
     init(text: String) {
         self.text = text
@@ -38,8 +39,10 @@ class JavaScriptHighlighter {
         self.attributed = mutableAttributed
     }
     
-    private func print(_ str: String) {
-        Swift.print("\(indent)\(str)")
+    private func print(_ str: @autoclosure () -> String) {
+        if debug {
+            Swift.print("\(indent)\(str())")
+        }
     }
     
     private func range(from: String.Index, to: String.Index) -> NSRange {

jstest/main.swift

@@ -9,5 +9,6 @@
 import Foundation
 
 let source = "`$foo ${blah} bar`"
-_ = JavaScriptHighlighter(text: source).highlight()
-
+let highlighter = JavaScriptHighlighter(text: source)
+highlighter.debug = true
+highlighter.highlight()