Fix Swift macro declarations with short names

.changeset/swift-short-macro.md

@@ -0,0 +1,5 @@
+---
+"@tanstack/highlight": patch
+---
+
+Recognize Swift macro declarations with short names while preserving identifiers and member calls.

src/languages/swift.ts

@@ -10,7 +10,7 @@ const patterns = [
   // Contextual words are keywords only before declarations, types, or as accessors.
   {
     className: 'keyword',
-    regex: /(?<!`)\b(?:(?<!\.)(?:associatedtype|as|async|await|break|case|catch|class|continue|convenience|default|defer|deinit|didSet|distributed|do|else|enum|extension|fallthrough|fileprivate|for|func|guard|if|import|in|indirect|inout|internal|is|let|mutating|nonisolated|nonmutating|operator|override|precedencegroup|private|protocol|public|repeat|rethrows|return|static|struct|subscript|switch|throw|throws|try|typealias|unowned|var|where|while|willSet)|init|self|Self|super)\b|(?<![\w.`])(?:(?:open|package|optional|dynamic|final|lazy|weak|required|prefix|infix|postfix|actor|macro|some|any|each|isolated|consuming|borrowing|sending)(?=[ \t]+(?:[a-z]{3}|[A-Z([]))|[gs]et(?=[ \t]*[{}]|[ \t]+[a-z]|\(\w+\)[ \t]*\{)|(?<=\()set(?=\)))/g,
+    regex: /(?<!`)\b(?:(?<!\.)(?:associatedtype|as|async|await|break|case|catch|class|continue|convenience|default|defer|deinit|didSet|distributed|do|else|enum|extension|fallthrough|fileprivate|for|func|guard|if|import|in|indirect|inout|internal|is|let|mutating|nonisolated|nonmutating|operator|override|precedencegroup|private|protocol|public|repeat|rethrows|return|static|struct|subscript|switch|throw|throws|try|typealias|unowned|var|where|while|willSet)|init|self|Self|super)\b|(?<![\w.`])(?:macro(?=[ \t]+[A-Za-z_]\w*[(<])|(?:open|package|optional|dynamic|final|lazy|weak|required|prefix|infix|postfix|actor|macro|some|any|each|isolated|consuming|borrowing|sending)(?=[ \t]+(?:[a-z]{3}|[A-Z([]))|[gs]et(?=[ \t]*[{}]|[ \t]+[a-z]|\(\w+\)[ \t]*\{)|(?<=\()set(?=\)))/g,
   },
   { className: 'literal', regex: /(?<![.`])\b(?:true|false|nil)\b/g },
   { className: 'type', regex: /\b(?:class|struct|enum|protocol|extension|actor|typealias|associatedtype)\s+(\w+)/g, group: 1 },

test/swift.test.ts

@@ -369,6 +369,16 @@ let package = Package(
     expect(classes(code, '.testTarget(name:')).toEqual([undefined, 'function', undefined, 'property', undefined])
   })
 
+  it('recognizes macro declarations with short names', () => {
+    for (const name of ['m', 'm<T>']) {
+      const code = `public macro ${name}() = #externalMacro(module: "M", type: "T")`
+      expect(classes(code, 'macro')).toEqual(['keyword'])
+      expect(classes(code, '#externalMacro')).toEqual(['meta'])
+    }
+    expect(classes('let macro = value', 'macro')).not.toContain('keyword')
+    expect(classes('value.macro()', 'macro')).toEqual(['function'])
+  })
+
   it('registers only the swift name', () => {
     expect(highlighter.normalizeLanguage('swift')).toBe('swift')
     expect(createHighlighter({ languages: [] }).normalizeLanguage('swift')).toBe('plaintext')