Add ca CLI prototype

.github/workflows/ci.yml

@@ -16,13 +16,12 @@ jobs:
       fail-fast: false
       matrix:
         os: [macos-latest, ubuntu-latest]
-        swift: ["6.0"]
+        swift: ["6.2"]
 
     steps:
       - uses: actions/checkout@v4
 
-      - name: Set up Swift (Linux)
-        if: runner.os != 'macOS'
+      - name: Set up Swift
         uses: swift-actions/setup-swift@v2
         with:
           swift-version: ${{ matrix.swift }}
@@ -31,12 +30,7 @@ jobs:
         id: swift-version
         run: |
           set -euo pipefail
-          if [ "${RUNNER_OS}" = "macOS" ]; then
-            SWIFT_BIN="$(xcrun -f swift)"
-          else
-            SWIFT_BIN="swift"
-          fi
-          SWIFT_VERSION="$("${SWIFT_BIN}" --version | head -n 1 | awk '{print $4}')"
+          SWIFT_VERSION="$(swift --version | head -n 1 | awk '{print $4}')"
           echo "version=${SWIFT_VERSION}" >> "${GITHUB_OUTPUT}"
           echo "Swift version: ${SWIFT_VERSION}"
 
@@ -59,12 +53,16 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      - name: Set up Swift
+        uses: swift-actions/setup-swift@v2
+        with:
+          swift-version: "6.2"
+
       - name: Resolve Swift version
         id: swift-version
         run: |
           set -euo pipefail
-          SWIFT_BIN="$(xcrun -f swift)"
-          SWIFT_VERSION="$("${SWIFT_BIN}" --version | head -n 1 | awk '{print $4}')"
+          SWIFT_VERSION="$(swift --version | head -n 1 | awk '{print $4}')"
           echo "version=${SWIFT_VERSION}" >> "${GITHUB_OUTPUT}"
           echo "Swift version: ${SWIFT_VERSION}"
 

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version: 5.9
+// swift-tools-version: 6.2
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription
@@ -25,9 +25,19 @@ let package = Package(
             name: "ChromaDemo",
             targets: ["ChromaDemo"]
         ),
+        .executable(
+            name: "ca",
+            targets: ["Ca"]
+        ),
     ],
     dependencies: [
         .package(url: "https://github.com/onevcat/Rainbow.git", from: "4.2.1"),
+        .package(url: "https://github.com/apple/swift-argument-parser", from: "1.4.0"),
+        .package(
+            url: "https://github.com/apple/swift-configuration",
+            from: "0.2.0",
+            traits: ["JSONSupport"]
+        ),
         .package(url: "https://github.com/ordo-one/package-benchmark", from: "1.20.0"),
     ],
     targets: [
@@ -57,6 +67,15 @@ let package = Package(
                 "ChromaBase46Themes",
             ]
         ),
+        .executableTarget(
+            name: "Ca",
+            dependencies: [
+                "Chroma",
+                "ChromaBase46Themes",
+                .product(name: "ArgumentParser", package: "swift-argument-parser"),
+                .product(name: "Configuration", package: "swift-configuration"),
+            ]
+        ),
         .executableTarget(
             name: "ChromaBenchmarks",
             dependencies: [
@@ -68,5 +87,6 @@ let package = Package(
                 .plugin(name: "BenchmarkPlugin", package: "package-benchmark"),
             ]
         ),
-    ]
+    ],
+    swiftLanguageModes: [.v5]
 )

README.md

@@ -60,6 +60,28 @@ To list all supported languages:
 swift run ChromaDemo --list-languages
 ```
 
+### Running ca (Experimental)
+
+`ca` is an experimental Chroma-powered `cat` replacement:
+
+```bash
+swift run ca Sources/Chroma/Highlighter.swift
+```
+
+Config file path: `~/.config/ca/config.json`
+
+```json
+{
+    "theme": {
+        "name": "tokyonight",
+        "appearance": "auto"
+    },
+    "lineNumbers": true,
+    "paging": "auto",
+    "headers": true
+}
+```
+
 ### Installation
 
 Add Chroma as a dependency in your `Package.swift`:

Sources/Ca/CaCommand.swift

@@ -0,0 +1,92 @@
+import ArgumentParser
+import Foundation
+
+@main
+struct CaCommand: AsyncParsableCommand {
+    static let configuration = CommandConfiguration(
+        commandName: "ca",
+        abstract: "A Chroma-powered cat replacement with syntax highlighting."
+    )
+
+    @Argument(help: "Files to display. Use '-' to read from stdin.")
+    var paths: [String] = []
+
+    @Option(help: "Theme name (ChromaBase46Themes or 'dark'/'light').")
+    var theme: String?
+
+    @Option(help: "Paging mode: auto, always, never.")
+    var paging: PagingMode?
+
+    @Flag(inversion: .prefixedNo, help: "Show line numbers.")
+    var lineNumbers: Bool?
+
+    @Flag(inversion: .prefixedNo, help: "Show file headers when rendering multiple inputs.")
+    var headers: Bool?
+
+    @Option(help: "Config file path (default: ~/.config/ca/config.json).")
+    var config: String?
+
+    mutating func run() async throws {
+        let loader = CaConfigLoader(filePathOverride: config)
+        var effectiveConfig = await loader.load()
+
+        if let theme {
+            effectiveConfig.theme.name = theme
+        }
+        if let paging {
+            effectiveConfig.paging = paging
+        }
+        if let lineNumbers {
+            effectiveConfig.lineNumbers = lineNumbers
+        }
+        if let headers {
+            effectiveConfig.headers = headers
+        }
+
+        do {
+            let inputs = try InputCollector().collect(paths: paths)
+            let theme = ThemeResolver().resolve(using: effectiveConfig)
+            let highlighter = HighlighterService(theme: theme, lineNumbers: effectiveConfig.lineNumbers)
+            let documents = try inputs.map { try highlighter.render($0) }
+            let lines = OutputComposer().compose(documents: documents, showHeaders: effectiveConfig.headers)
+            output(lines: lines, paging: effectiveConfig.paging)
+        } catch let error as CaError {
+            Diagnostics.printError(error.description)
+            throw ExitCode.failure
+        } catch {
+            Diagnostics.printError("Unexpected error: \(error)")
+            throw ExitCode.failure
+        }
+    }
+
+    private func output(lines: [String], paging: PagingMode) {
+        switch paging {
+        case .never:
+            write(lines)
+        case .always:
+            if let pager = Pager(lines: lines) {
+                pager.run()
+            } else {
+                write(lines)
+            }
+        case .auto:
+            if shouldPage(lines: lines), let pager = Pager(lines: lines) {
+                pager.run()
+            } else {
+                write(lines)
+            }
+        }
+    }
+
+    private func shouldPage(lines: [String]) -> Bool {
+        guard Terminal.isInteractive, let size = Terminal.size() else { return false }
+        return lines.count > size.rows
+    }
+
+    private func write(_ lines: [String]) {
+        let output = lines.joined(separator: "\n")
+        if let data = output.data(using: .utf8) {
+            FileHandle.standardOutput.write(data)
+        }
+    }
+}

Sources/Ca/CaConfig.swift

@@ -0,0 +1,36 @@
+import ArgumentParser
+import Chroma
+import Foundation
+
+struct CaConfig: Equatable {
+    struct ThemeSelection: Equatable {
+        var name: String?
+        var appearance: ThemeAppearancePreference
+    }
+
+    var theme: ThemeSelection
+    var lineNumbers: Bool
+    var paging: PagingMode
+    var headers: Bool
+
+    static let `default` = CaConfig(
+        theme: .init(name: nil, appearance: .auto),
+        lineNumbers: true,
+        paging: .auto,
+        headers: true
+    )
+}
+
+enum ThemeAppearancePreference: String {
+    case auto
+    case dark
+    case light
+}
+
+enum PagingMode: String, CaseIterable {
+    case auto
+    case always
+    case never
+}
+
+extension PagingMode: ExpressibleByArgument {}

Sources/Ca/CaError.swift

@@ -0,0 +1,21 @@
+import Foundation
+
+enum CaError: Error, CustomStringConvertible {
+    case missingInput
+    case fileNotFound(String)
+    case unreadableFile(String)
+    case directoryNotSupported(String)
+
+    var description: String {
+        switch self {
+        case .missingInput:
+            return "No input provided. Pass a file path or pipe content into ca."
+        case .fileNotFound(let path):
+            return "File not found: \(path)"
+        case .unreadableFile(let path):
+            return "Unable to read file: \(path)"
+        case .directoryNotSupported(let path):
+            return "Directory input is not supported yet: \(path)"
+        }
+    }
+}