Supports exact: package requirement

Author: stevapple

CodeGeneration/Sources/SyntaxSupport/KeywordSpec.swift

@@ -124,6 +124,7 @@ public let KEYWORDS: [KeywordSpec] = [
   KeywordSpec("else", isLexerClassified: true, requiresTrailingSpace: true),
   KeywordSpec("enum", isLexerClassified: true, requiresTrailingSpace: true),
   KeywordSpec("escaping"),
+  KeywordSpec("exact"),
   KeywordSpec("exclusivity"),
   KeywordSpec("exported"),
   KeywordSpec("extension", isLexerClassified: true, requiresTrailingSpace: true),

CodeGeneration/Sources/SyntaxSupport/gyb_generated/AttributeNodes.swift

@@ -213,7 +213,7 @@ public let ATTRIBUTE_NODES: [Node] = [
                description: "The comma before the package requirement, if it exists.",
                isOptional: true),
          Child(name: "RequirementLabel",
-               kind: .token(choices: [.keyword(text: "branch"), .keyword(text: "from"), .keyword(text: "revision")]),
+               kind: .token(choices: [.keyword(text: "branch"), .keyword(text: "exact"), .keyword(text: "from"), .keyword(text: "revision")]),
                description: "The requirement label.",
                isOptional: true),
          Child(name: "RequirementColon",

Sources/SwiftParser/Attributes.swift

@@ -885,8 +885,8 @@ extension Parser {
     let requirement: RawExprSyntax?
     if locationLabel.tokenKind != .keyword(.path) {
       (unexpectedBeforeRequirementComma, requirementComma) = self.expect(.comma)
-      if self.at(any: [.keyword(.from), .keyword(.branch), .keyword(.revision)]) {
-        (unexpectedBeforeRequirementLabel, requirementLabel) = self.expectAny([.keyword(.from), .keyword(.branch), .keyword(.revision)], default: .keyword(.from))
+      if self.at(any: [.keyword(.from), .keyword(.exact), .keyword(.branch), .keyword(.revision)]) {
+        (unexpectedBeforeRequirementLabel, requirementLabel) = self.expectAny([.keyword(.from), .keyword(.exact), .keyword(.branch), .keyword(.revision)], default: .keyword(.from))
         (unexpectedBeforeRequirementColon, requirementColon) = self.expect(.colon)
         requirement = self.parseStringLiteral().as(RawExprSyntax.self)
       } else {

Sources/SwiftSyntax/generated/Keyword.swift

@@ -199,6 +199,8 @@ public enum Keyword: UInt8, Hashable {
 
   case escaping
 
+  case exact
+  
   case exclusivity
 
   case exported
@@ -554,6 +556,8 @@ public enum Keyword: UInt8, Hashable {
         self = .cType
       case "defer": 
         self = .`defer`
+      case "exact": 
+        self = .exact
       case "false": 
         self = .`false`
       case "final": 
@@ -1159,6 +1163,7 @@ public enum Keyword: UInt8, Hashable {
     "else", 
     "enum", 
     "escaping", 
+    "exact", 
     "exclusivity", 
     "exported", 
     "extension", 

gyb_syntax_support/AttributeNodes.py

@@ -224,7 +224,7 @@
                    The comma before the package requirement, if it exists.
                    '''),
              Child('RequirementLabel', kind='IdentifierToken',
-                   token_choices=['KeywordToken|branch', 'KeywordToken|from', 'KeywordToken|revision'],
+                   token_choices=['KeywordToken|branch', 'KeywordToken|exact', 'KeywordToken|from', 'KeywordToken|revision'],
                    description='The requirement label.', is_optional=True),
              Child('RequirementColon', kind='ColonToken', is_optional=True),
              Child('Requirement', kind='Expr',