(swift) Improved highlighting for functions, initializers, and subscr…

…ipts (#2930)

This PR improves highlighting for functions, initializers, and subscripts. This includes detailed highlighting for generic parameters as well as function parameters.

To differentiate between tuple elements and function params, I've also added a mode to match tuples, whose element names should not be highlighted as params.

- Fixes #2895
- Fixes #2857

CHANGES.md

@@ -28,6 +28,7 @@ Language grammar improvements:
   - Added support for quoted identifiers, implicit parameters, and property wrapper projections
   - Support for more complex expressions in string interpolation
 - enh(swift) Improved highlighting for types and generic arguments (#2920) [Steven Van Impe][]
+- enh(swift) Improved highlighting for functions, initializers, and subscripts (#2930) [Steven Van Impe][]
 - fix(http) avoid recursive sublanguage and tighten rules (#2893) [Josh Goebel][]
 - fix(asciidoc): Handle section titles level 5 (#2868) [Vaibhav Chanana][]
 - fix(asciidoc): Support unconstrained emphasis syntax (#2869) [Guillaume Grossetie][]

src/languages/lib/kws_swift.js

@@ -52,7 +52,7 @@ export const keywords = [
   'enum',
   'extension',
   'fallthrough',
-  'fileprivate(set)',
+  /fileprivate\(set\)/,
   'fileprivate',
   'final', // contextual
   'for',
@@ -66,26 +66,26 @@ export const keywords = [
   /init\?/,
   /init!/,
   'inout',
-  'internal(set)',
+  /internal\(set\)/,
   'internal',
   'in',
   'is', // operator
   'lazy', // contextual
   'let',
   'mutating', // contextual
   'nonmutating', // contextual
-  'open(set)', // contextual
+  /open\(set\)/, // contextual
   'open', // contextual
   'operator',
   'optional', // contextual
   'override', // contextual
   'postfix', // contextual
   'precedencegroup',
   'prefix', // contextual
-  'private(set)',
+  /private\(set\)/,
   'private',
   'protocol',
-  'public(set)',
+  /public\(set\)/,
   'public',
   'repeat',
   'required', // contextual
@@ -104,8 +104,8 @@ export const keywords = [
   /try!/, // operator
   'try', // operator
   'typealias',
-  'unowned(safe)', // contextual
-  'unowned(unsafe)', // contextual
+  /unowned\(safe\)/, // contextual
+  /unowned\(unsafe\)/, // contextual
   'unowned', // contextual
   'var',
   'weak', // contextual
@@ -240,7 +240,7 @@ export const identifierHead = either(
   /[\u2C00-\u2DFF\u2E80-\u2FFF]/,
   /[\u3004-\u3007\u3021-\u302F\u3031-\u303F\u3040-\uD7FF]/,
   /[\uF900-\uFD3D\uFD40-\uFDCF\uFDF0-\uFE1F\uFE30-\uFE44]/,
-  /[\uFE47-\uFFFD]/
+  /[\uFE47-\uFEFE\uFF00-\uFFFD]/ // Should be /[\uFE47-\uFFFD]/, but we have to exclude FEFF.
   // The following characters are also allowed, but the regexes aren't supported yet.
   // /[\u{10000}-\u{1FFFD}\u{20000-\u{2FFFD}\u{30000}-\u{3FFFD}\u{40000}-\u{4FFFD}]/u,
   // /[\u{50000}-\u{5FFFD}\u{60000-\u{6FFFD}\u{70000}-\u{7FFFD}\u{80000}-\u{8FFFD}]/u,