Swift 6 concurrency mode

API changes:

* Compatible with Swift 6 concurrency mode
  * METAR, TAF, and associated objects all now Sendable
  * parse functions are now async
* Added Visibility.notRecorded case to differentiate "VSNO" from "M"
* More lenient parsing of direction ranges
* Minimum OS versions advanced
* Removed unused Error case

Internal changes:

* Uses new RegexBuilder API instead of NSRegularExpression
  * METAR, TAF, and Remarks parsers are now actors that preload their Regex instances
  * Individual component parsers are now classes instead of functions
  * Added RegexCases protocol for enums that are parsed from a Regex
* Stricter handling of TAF periods that cross month boundaries
* Moved remarks files at top level alongside METAR and TAF files

Test changes:

* Uses async support in Quick
* Added more test cases for fractional distances and direction ranges

Supporting changes:

* Gauntlet now uses ArgumentParser
* Gauntlet no longer uses gzipped URLs, to support async streaming

Author: RISCfuture

.github/workflows/ci.yml

@@ -16,11 +16,11 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        swift: ["5.9", "5.10"]
-        os: [macos-14]
+        swift: ["6.0"]
+        os: [macos-15]
     runs-on: ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: swift-actions/setup-swift@v2
         with:
           swift-version: ${{ matrix.swift }}

.github/workflows/doc.yml

@@ -22,10 +22,10 @@ jobs:
     name: Generate Documentation
     runs-on: macos-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: swift-actions/setup-swift@v2
         with:
-          swift-version: "5.10"
+          swift-version: "6.0"
       - name: Build
         run: |
           swift package \
@@ -35,7 +35,7 @@ jobs:
            --transform-for-static-hosting \
            --hosting-base-path SwiftMETAR
       - name: Upload
-        uses: actions/upload-pages-artifact@v1
+        uses: actions/upload-pages-artifact@v3
         with:
           path: "docs/"
 
@@ -49,4 +49,4 @@ jobs:
     steps:
       - name: Deploy to GitHub Pages
         id: deployment
-        uses: actions/deploy-pages@v2
+        uses: actions/deploy-pages@v4

Package.resolved

@@ -1,12 +1,11 @@
-// swift-tools-version:5.9
-// The swift-tools-version declares the minimum version of Swift required to build this package.
+// swift-tools-version: 6.0
 
 import PackageDescription
 
 let package = Package(
     name: "SwiftMETAR",
     defaultLocalization: "en",
-    platforms: [.macOS(.v13), .iOS(.v16), .watchOS(.v9), .tvOS(.v16)],
+    platforms: [.macOS(.v15), .iOS(.v18), .watchOS(.v11), .tvOS(.v18)],
     products: [
         // Products define the executables and libraries a package produces, and make them visible to other packages.
         .library(
@@ -16,24 +15,27 @@ let package = Package(
     ],
     dependencies: [
         // Dependencies declare other packages that this package depends on.
-        .package(url: "https://github.com/Quick/Quick.git", from: "4.0.0"),
-        .package(url: "https://github.com/Quick/Nimble.git", from: "9.2.0"),
-        .package(url: "https://github.com/objecthub/swift-numberkit.git", from: "2.4.2"),
-        .package(url: "https://github.com/sharplet/Regex.git", from: "2.1.0"),
-        .package(url: "https://github.com/apple/swift-docc-plugin.git", from: "1.0.0"),
-        .package(url: "https://github.com/1024jp/GzipSwift.git", from: "6.0.0"),
+        .package(url: "https://github.com/Quick/Quick.git", from: "7.6.2"),
+        .package(url: "https://github.com/Quick/Nimble.git", from: "13.6.0"),
+        .package(url: "https://github.com/objecthub/swift-numberkit.git", from: "2.6.0"),
+        .package(url: "https://github.com/apple/swift-docc-plugin.git", from: "1.4.3"),
+        .package(url: "https://github.com/apple/swift-argument-parser.git", from: "1.5.0")
     ],
     targets: [
         // Targets are the basic building blocks of a package. A target can define a module or a test suite.
         // Targets can depend on other targets in this package, and on products in packages this package depends on.
         .target(
             name: "SwiftMETAR",
-            dependencies: [.product(name: "NumberKit", package: "swift-numberkit"), "Regex"]),
+            dependencies: [.product(name: "NumberKit", package: "swift-numberkit")]),
         .testTarget(
             name: "SwiftMETARTests",
             dependencies: ["SwiftMETAR", "Quick", "Nimble"]),
         .executableTarget(
             name: "SwiftMETARGauntlet",
-            dependencies: ["SwiftMETAR", .product(name: "Gzip", package: "GzipSwift")])
-    ]
+            dependencies: [
+                "SwiftMETAR",
+                .product(name: "ArgumentParser", package: "swift-argument-parser")
+            ])
+    ],
+    swiftLanguageModes: [.v5, .v6]
 )

Package.swift

@@ -47,7 +47,7 @@ To parse a METAR in String format, simply call `METAR.from`. You will get back a
 that you can query for weather information:
 
 ```swift
-let observation = try METAR.from(string: myString)
+let observation = try await METAR.from(string: myString)
 if let winds = observation.winds {
     switch winds {
         case let .direction(heading, speed, gust):

README.md

@@ -1,7 +1,7 @@
 import Foundation
 
 /// A sea-level pressure altimeter setting.
-public enum Altimeter: Codable, Comparable {
+public enum Altimeter: Codable, Comparable, Sendable {
 
     /**
      An altimeter setting in inches of mercury (typical in the US).

Sources/SwiftMETAR/Common/Altimeter.swift

@@ -1,8 +1,8 @@
 import Foundation
 
 /// A sky condition, either a cloud layer or the presence of a clear sky.
-public enum Condition: Codable, Equatable {
-    
+public enum Condition: Codable, Equatable, Sendable {
+
     /// Sky clear below 12,000 feet (USA) or 25,000 feet (Canada). Typically
     /// reported by automated ceilometers.
     case clear
@@ -135,7 +135,7 @@ public enum Condition: Codable, Equatable {
     }
 
     /// Types of vertical development that a cloud layer can have.
-    public enum CeilingType: String, Codable, CaseIterable {
+    public enum CeilingType: String, Codable, RegexCases, Sendable {
 
         /// Layer consists of cumulonimbus clouds.
         case cumulonimbus = "CB"

Sources/SwiftMETAR/Common/Condition.swift

@@ -0,0 +1,4 @@
+func parseLocationID(_ parts: inout Array<String.SubSequence>) throws -> String {
+    guard !parts.isEmpty else { throw Error.badFormat }
+    return String(parts.removeFirst())
+}

Sources/SwiftMETAR/Common/Parsers/CommonParsers.swift

@@ -1,64 +1,71 @@
 import Foundation
-import Regex
+@preconcurrency import RegexBuilder
 
-fileprivate let types = Condition.CeilingType.allCases
-    .map { NSRegularExpression.escapedPattern(for: $0.rawValue) }
-    .joined(separator: "|")
-fileprivate let conditionsRxStr = "^(FEW|SCT|BKN|OVC|VV)(\\d+)(\(types))?$"
-fileprivate let conditionsRx = try! Regex(string: conditionsRxStr)
+class ConditionsParser {
+    private enum Coverage: String, RegexCases {
+        case few = "FEW"
+        case scattered = "SCT"
+        case broken = "BKN"
+        case overcast = "OVC"
+        case verticalVis = "VV"
+    }
 
-func parseConditions(_ parts: inout Array<String.SubSequence>) throws -> Array<Condition> {
-    if parts.isEmpty { return [] }
-    
-    var conditions = Array<Condition>()
-    
-    while true {
-        if parts.isEmpty { return conditions }
-        let condStr = String(parts[0])
-        
-        switch condStr {
-        case "SKC":
-            parts.removeFirst()
-            return [.skyClear]
-        case "CLR", "NCD":
-            parts.removeFirst()
-            return [.clear]
-        case "NSC":
-            parts.removeFirst()
-            return [.noSignificantClouds]
-        case "CAVOK":
-            parts.removeFirst()
-            return [.cavok]
-        default:
-            break
-        }
-        
-        if let match = conditionsRx.firstMatch(in: condStr) {
-            parts.removeFirst()
-            
-            guard let coverage = match.captures[0],
-                  let flightLevelStr = match.captures[1],
-                  let flightLevel = UInt(flightLevelStr) else { throw Error.invalidConditions(condStr) }
-            let height = flightLevel*100
-            
-            var type: Condition.CeilingType? = nil
-            if let typeStr = match.captures[2] {
-                guard coverage != "VV" else { throw Error.invalidConditions(condStr) }
-                type = Condition.CeilingType(rawValue: typeStr)
-                guard type != nil else {
-                    throw Error.invalidConditions(condStr)
-                }
+    private let coverageRef = Reference<Coverage>()
+    private let heightRef = Reference<UInt>()
+    private let ceilingTypeRef = Reference<Condition.CeilingType?>()
+    private lazy var rx = Regex {
+        Anchor.startOfSubject
+        Capture(as: coverageRef) { try! Coverage.rx } transform: { .init(rawValue: String($0))! }
+        Capture(as: heightRef) { Repeat(.digit, count: 3) } transform: { UInt($0)! * 100 }
+        Capture(as: ceilingTypeRef) {
+            Optionally(try! Condition.CeilingType.rx)
+        } transform: { .init(rawValue: String($0)) }
+        Anchor.endOfSubject
+    }
+
+    func parse(_ parts: inout Array<String.SubSequence>) throws -> Array<Condition> {
+        if parts.isEmpty { return [] }
+
+        var conditions = Array<Condition>()
+
+        while true {
+            if parts.isEmpty { return conditions }
+            let condStr = String(parts[0])
+
+            switch condStr {
+                case "SKC":
+                    parts.removeFirst()
+                    return [.skyClear]
+                case "CLR", "NCD":
+                    parts.removeFirst()
+                    return [.clear]
+                case "NSC":
+                    parts.removeFirst()
+                    return [.noSignificantClouds]
+                default:
+                    break
             }
-            
-            switch coverage {
-                case "FEW": conditions.append(.few(height, type: type))
-                case "SCT": conditions.append(.scattered(height, type: type))
-                case "BKN": conditions.append(.broken(height, type: type))
-                case "OVC": conditions.append(.overcast(height, type: type))
-                case "VV": conditions.append(.indefinite(height))
-                default: throw Error.invalidConditions(condStr)
+
+            if let match = try rx.wholeMatch(in: condStr) {
+                parts.removeFirst()
+
+                let coverage = match[coverageRef],
+                    height = match[heightRef],
+                    type = match[ceilingTypeRef]
+
+                if type != nil {
+                    guard coverage != .verticalVis else { throw Error.invalidConditions(condStr) }
+                }
+
+                switch coverage {
+                    case .few: conditions.append(.few(height, type: type))
+                    case .scattered: conditions.append(.scattered(height, type: type))
+                    case .broken: conditions.append(.broken(height, type: type))
+                    case .overcast: conditions.append(.overcast(height, type: type))
+                    case .verticalVis: conditions.append(.indefinite(height))
+                }
             }
+            else { return conditions }
         }
-        else { return conditions }
     }
 }