format-aware highlighting: code files get code mode, others fall back to Cordial/markdown

src/EditorView.swift

@@ -908,6 +908,7 @@ struct EditorView: View {
         EditorTextView(
             text: bodyBinding,
             evalResults: offsetEvalResults(state.evalResults),
+            fileFormat: state.currentFileFormat,
             onEvaluate: { state.evaluate() },
             onBackspaceAtStart: {
                 NotificationCenter.default.post(name: .focusTitle, object: nil)
@@ -928,6 +929,7 @@ struct EditorView: View {
 struct EditorTextView: NSViewRepresentable {
     @Binding var text: String
     var evalResults: [Int: String]
+    var fileFormat: FileFormat = .markdown
     var onEvaluate: () -> Void
     var onBackspaceAtStart: (() -> Void)? = nil
 
@@ -983,7 +985,7 @@ struct EditorTextView: NSViewRepresentable {
 
         if let ts = textView.textStorage {
             ts.beginEditing()
-            applySyntaxHighlighting(to: ts)
+            applySyntaxHighlighting(to: ts, format: fileFormat)
             ts.endEditing()
         }
         textView.typingAttributes = [
@@ -1007,7 +1009,7 @@ struct EditorTextView: NSViewRepresentable {
             textView.string = text
             if let ts = textView.textStorage {
                 ts.beginEditing()
-                applySyntaxHighlighting(to: ts)
+                applySyntaxHighlighting(to: ts, format: fileFormat)
                 ts.endEditing()
             }
             textView.selectedRanges = selectedRanges
@@ -1056,7 +1058,7 @@ struct EditorTextView: NSViewRepresentable {
                     .foregroundColor: palette.text
                 ]
                 ts.beginEditing()
-                applySyntaxHighlighting(to: ts)
+                applySyntaxHighlighting(to: ts, format: parent.fileFormat)
                 ts.endEditing()
                 tv.needsDisplay = true
             }
@@ -1077,7 +1079,7 @@ struct EditorTextView: NSViewRepresentable {
             parent.text = tv.string
             let sel = tv.selectedRanges
             ts.beginEditing()
-            applySyntaxHighlighting(to: ts)
+            applySyntaxHighlighting(to: ts, format: parent.fileFormat)
             ts.endEditing()
             tv.typingAttributes = [
                 .font: Theme.editorFont,
@@ -1175,7 +1177,7 @@ struct EditorTextView: NSViewRepresentable {
             let sel = tv.selectedRanges
             ts.beginEditing()
             ts.replaceCharacters(in: range, with: newMarkdown)
-            applySyntaxHighlighting(to: ts)
+            applySyntaxHighlighting(to: ts, format: parent.fileFormat)
             ts.endEditing()
             tv.selectedRanges = sel
             parent.text = tv.string
@@ -1396,7 +1398,7 @@ private let syntaxBooleans: Set<String> = ["true", "false"]
 
 private let syntaxOperatorChars = CharacterSet(charactersIn: "+-*/=^<>!(){}[]:,.&|%")
 
-func applySyntaxHighlighting(to textStorage: NSTextStorage) {
+func applySyntaxHighlighting(to textStorage: NSTextStorage, format: FileFormat = .markdown) {
     let text = textStorage.string
     let fullRange = NSRange(location: 0, length: (text as NSString).length)
     let palette = Theme.current
@@ -1409,6 +1411,11 @@ func applySyntaxHighlighting(to textStorage: NSTextStorage) {
     ]
     textStorage.setAttributes(baseAttrs, range: fullRange)
 
+    if format.isCode {
+        applyCodeFileHighlighting(to: textStorage, syn: syn, baseFont: baseFont)
+        return
+    }
+
     let fencedRanges = highlightFencedCodeBlocks(textStorage: textStorage, palette: palette, baseFont: baseFont)
     let tableHeaderLines = findTableHeaderLines(textStorage: textStorage, fencedRanges: fencedRanges)
 
@@ -1457,6 +1464,21 @@ func applySyntaxHighlighting(to textStorage: NSTextStorage) {
     highlightAutolinks(textStorage: textStorage, palette: palette, fencedRanges: fencedRanges)
 }
 
+private func applyCodeFileHighlighting(to textStorage: NSTextStorage, syn: Theme.SyntaxColors, baseFont: NSFont) {
+    let text = textStorage.string
+    let nsText = text as NSString
+    var lineStart = 0
+
+    while lineStart < nsText.length {
+        let lineRange = nsText.lineRange(for: NSRange(location: lineStart, length: 0))
+        let line = nsText.substring(with: lineRange)
+        highlightCodeLine(line, lineRange: lineRange, textStorage: textStorage, syn: syn)
+        lineStart = NSMaxRange(lineRange)
+    }
+
+    highlightBlockComments(textStorage: textStorage, syn: syn, baseFont: baseFont)
+}
+
 private func highlightMarkdownLine(_ trimmed: String, line: String, lineRange: NSRange, textStorage: NSTextStorage, baseFont: NSFont, palette: CatppuccinPalette, isTableHeader: Bool = false) -> Bool {
     if trimmed.hasPrefix("### ") {
         let hashRange = (textStorage.string as NSString).range(of: "###", range: lineRange)