From 4da9bbd0bc14d5774b112fc4bb1859d5a67fb478 Mon Sep 17 00:00:00 2001
From: John Sundell <john@sundell.co>
Date: Mon, 30 Dec 2019 23:39:54 +0000
Subject: [PATCH] =?UTF-8?q?Add=20support=20for=20the=20=E2=80=9Cprefix?=
 =?UTF-8?q?=E2=80=9D=20keyword=20(#91)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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This patch makes Splash correctly highlight the `prefix` keyword, which
can only appear before `func`, so a special case was added for it (for now).
---
 Sources/Splash/Grammar/SwiftGrammar.swift     |  4 +++
 .../SplashTests/Tests/DeclarationTests.swift  | 26 +++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/Sources/Splash/Grammar/SwiftGrammar.swift b/Sources/Splash/Grammar/SwiftGrammar.swift
index 1dbf34d..05bd9a4 100644
--- a/Sources/Splash/Grammar/SwiftGrammar.swift
+++ b/Sources/Splash/Grammar/SwiftGrammar.swift
@@ -287,6 +287,10 @@ private extension SwiftGrammar {
         var tokenType: TokenType { return .keyword }
 
         func matches(_ segment: Segment) -> Bool {
+            if segment.tokens.current == "prefix" && segment.tokens.next == "func" {
+                return true
+            }
+
             if segment.tokens.next == ":" {
                 // Nil pattern matching inside of a switch statement case
                 if segment.tokens.current == "nil" {
diff --git a/Tests/SplashTests/Tests/DeclarationTests.swift b/Tests/SplashTests/Tests/DeclarationTests.swift
index 8256747..58453c3 100644
--- a/Tests/SplashTests/Tests/DeclarationTests.swift
+++ b/Tests/SplashTests/Tests/DeclarationTests.swift
@@ -955,6 +955,31 @@ final class DeclarationTests: SyntaxHighlighterTestCase {
         ])
     }
 
+    func testPrefixFunctionDeclaration() {
+        let components = highlighter.highlight("prefix func !(rhs: Bool) -> Bool { !rhs }")
+
+        XCTAssertEqual(components, [
+            .token("prefix", .keyword),
+            .whitespace(" "),
+            .token("func", .keyword),
+            .whitespace(" "),
+            .plainText("!(rhs:"),
+            .whitespace(" "),
+            .token("Bool", .type),
+            .plainText(")"),
+            .whitespace(" "),
+            .plainText("->"),
+            .whitespace(" "),
+            .token("Bool", .type),
+            .whitespace(" "),
+            .plainText("{"),
+            .whitespace(" "),
+            .plainText("!rhs"),
+            .whitespace(" "),
+            .plainText("}")
+        ])
+    }
+
     func testIndirectEnumDeclaration() {
         let components = highlighter.highlight("""
         indirect enum Content {
@@ -1064,6 +1089,7 @@ extension DeclarationTests {
             ("testNonMutatingFunction", testNonMutatingFunction),
             ("testRethrowingFunctionDeclaration", testRethrowingFunctionDeclaration),
             ("testFunctionDeclarationWithOpaqueReturnType", testFunctionDeclarationWithOpaqueReturnType),
+            ("testPrefixFunctionDeclaration", testPrefixFunctionDeclaration),
             ("testIndirectEnumDeclaration", testIndirectEnumDeclaration),
             ("testWrappedPropertyDeclarations", testWrappedPropertyDeclarations)
         ]