JavaScript Highlighter code cleanup

MongoView/Synax Highlighting/JavaScriptHighlighter.swift

@@ -77,8 +77,25 @@ class JavaScriptHighlighter {
 
         return attributed
     }
+    
+    private func emit(token: TokenType, range: NSRange) {
+        let color: NSColor
+        switch token {
+        case .string:
+            color = .systemRed
+        case .number:
+            color = .systemBlue
+        case .punctuation:
+            color = .systemTeal
+        case .identifier:
+            return
+        }
+        attributed.addAttribute(.foregroundColor, value: color, range: range)
+    }
 
     private func consumeExpression() {
+        consumeWhitespace()
+        
         guard let char = peek() else { return }
         
         if identifierStarts.contains(char) {
@@ -103,6 +120,13 @@ class JavaScriptHighlighter {
             consume()
         }
     }
+    
+    private func consumeWhitespace(newlines: Bool = false) {
+        let charSet = newlines ? CharacterSet.whitespacesAndNewlines : .whitespaces
+        while let char = peek(), charSet.contains(char) {
+            consume()
+        }
+    }
 
     private func consumeIdentifier() {
         let identifierStart = currentIndex!
@@ -124,7 +148,7 @@ class JavaScriptHighlighter {
             }
         }
         print("Number: \(text[numberStart..<currentIndex])")
-        attributed.addAttribute(.foregroundColor, value: NSColor.systemBlue, range: range(from: numberStart, to: currentIndex))
+        emit(token: .number, range: range(from: numberStart, to: currentIndex))
     }
     
     private func consumeString() {
@@ -137,7 +161,7 @@ class JavaScriptHighlighter {
             consume() // string closing quote
         }
         print("String: \(text[stringStart..<currentIndex])")
-        attributed.addAttribute(.foregroundColor, value: NSColor.systemRed, range: range(from: stringStart, to: currentIndex))
+        emit(token: .string, range: range(from: stringStart, to: currentIndex))
     }
     
     private func consumeTemplateString() {
@@ -148,7 +172,7 @@ class JavaScriptHighlighter {
                 consume() // $
                 consume() // {
                 print("Template string fragment: '\(text[stringFragmentStart!..<currentIndex])'")
-                attributed.addAttribute(.foregroundColor, value: NSColor.systemRed, range: range(from: stringFragmentStart!, to: currentIndex))
+                emit(token: .string, range: range(from: stringFragmentStart!, to: currentIndex))
                 consumeTemplateStringExpression()
                 stringFragmentStart = currentIndex
                 if currentIndex < text.endIndex && peek() == "}" {
@@ -158,7 +182,7 @@ class JavaScriptHighlighter {
                 stringFragmentStart = stringFragmentStart ?? currentIndex
                 consume() // `
                 print("Template string fragment: '\(text[stringFragmentStart!..<currentIndex])'")
-                attributed.addAttribute(.foregroundColor, value: NSColor.systemRed, range: range(from: stringFragmentStart!, to: currentIndex))
+                emit(token: .string, range: range(from: stringFragmentStart!, to: currentIndex))
                 stringFragmentStart = nil
                 break
             } else {
@@ -167,7 +191,7 @@ class JavaScriptHighlighter {
         }
         if let start = stringFragmentStart {
             print("Template string fragment: '\(text[start..<currentIndex])'")
-            attributed.addAttribute(.foregroundColor, value: NSColor.systemRed, range: range(from: start, to: currentIndex))
+            emit(token: .string, range: range(from: start, to: currentIndex))
         }
     }
     
@@ -187,7 +211,7 @@ class JavaScriptHighlighter {
     private func consumeFunctionCallOrGrouping() {
         consume() // (
         print("Opening (")
-        attributed.addAttribute(.foregroundColor, value: NSColor.systemTeal, range: prevCharRange())
+        emit(token: .punctuation, range: prevCharRange())
         indent += "  "
         while currentIndex < text.endIndex && peek() != ")" {
             consumeExpression()
@@ -196,14 +220,14 @@ class JavaScriptHighlighter {
         if currentIndex < text.endIndex {
             consume() // )
             print("Closing )")
-            attributed.addAttribute(.foregroundColor, value: NSColor.systemTeal, range: prevCharRange())
+            emit(token: .punctuation, range: prevCharRange())
         }
     }
     
     private func consumeObject() {
         consume() // {
         print("Opening {")
-        attributed.addAttribute(.foregroundColor, value: NSColor.systemTeal, range: prevCharRange())
+        emit(token: .punctuation, range: prevCharRange())
         indent += "  "
         object:
         while currentIndex < text.endIndex && peek() != "}" {
@@ -226,7 +250,7 @@ class JavaScriptHighlighter {
         if currentIndex < text.endIndex {
             consume() // }
             print("Closing }")
-            attributed.addAttribute(.foregroundColor, value: NSColor.systemTeal, range: prevCharRange())
+            emit(token: .punctuation, range: prevCharRange())
         }
     }
     
@@ -244,13 +268,13 @@ class JavaScriptHighlighter {
     private func consumeDotLookup() {
         consume() // .
         print("Dot lookup")
-        attributed.addAttribute(.foregroundColor, value: NSColor.systemTeal, range: prevCharRange())
+        emit(token: .punctuation, range: prevCharRange())
     }
     
     private func consumeArray() {
         consume() // [
         print("Opening [")
-        attributed.addAttribute(.foregroundColor, value: NSColor.systemTeal, range: prevCharRange())
+        emit(token: .punctuation, range: prevCharRange())
         indent += "  "
         array:
         while currentIndex < text.endIndex && peek() != "]" {
@@ -258,6 +282,8 @@ class JavaScriptHighlighter {
             while currentIndex < text.endIndex {
                 if peek() == "," {
                     consume() // ,
+                    print("Array separator")
+                    emit(token: .punctuation, range: prevCharRange())
                     break
                 } else if peek() == "]" {
                     break array
@@ -272,8 +298,17 @@ class JavaScriptHighlighter {
         if currentIndex < text.endIndex {
             consume() // ]
             print("Closing ]")
-            attributed.addAttribute(.foregroundColor, value: NSColor.systemTeal, range: prevCharRange())
+            emit(token: .punctuation, range: prevCharRange())
         }
     }
     
 }
+
+extension JavaScriptHighlighter {
+    enum TokenType {
+        case identifier
+        case punctuation
+        case number
+        case string
+    }
+}