cli: Add Initial Cli Work

Signed-off-by: Will Hawkins <hawkinsw@obs.cr>

Package.resolved

@@ -1,6 +1,15 @@
 {
-  "originHash" : "3969417c2a67000e225174da55741dc4261b615b990ae4ce381417f06c5e9099",
+  "originHash" : "5d36627594955e7c1e9d5ca6b02c23ee9dc8e0d4ce73dc310b34fa6d1b966434",
   "pins" : [
+    {
+      "identity" : "swift-argument-parser",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/apple/swift-argument-parser",
+      "state" : {
+        "revision" : "626b5b7b2f45e1b0b1c6f4a309296d1d21d7311b",
+        "version" : "1.7.1"
+      }
+    },
     {
       "identity" : "swift-docc-plugin",
       "kind" : "remoteSourceControl",

Package.swift

@@ -5,7 +5,7 @@ import CompilerPluginSupport
 import PackageDescription
 
 let package = Package(
-    name: "p4rse",
+  name: "p4ce",
   platforms: [.iOS(.v17), .macOS(.v13)],
   products: [
     // Products define the executables and libraries a package produces, making them visible to other packages.
@@ -25,12 +25,17 @@ let package = Package(
       name: "P4Runtime",
       targets: ["P4Runtime"]
     ),
+    .executable(
+      name: "p4ce",
+      targets: ["Cli"]
+    ),
   ],
   dependencies: [
     .package(path: "./tree-sitter-p4"),
     .package(url: "https://github.com/tree-sitter/swift-tree-sitter", revision: "main"),
     .package(url: "https://github.com/apple/swift-docc-plugin", from: "1.0.0"),
     .package(url: "https://github.com/swiftlang/swift-syntax", from: "602.0.0"),
+    .package(url: "https://github.com/apple/swift-argument-parser", from: "1.0.0"),
   ],
   targets: [
     .macro(
@@ -73,9 +78,19 @@ let package = Package(
       name: "P4Runtime",
       dependencies: ["P4Lang", "Common"]
     ),
+    .executableTarget(
+      name: "Cli",
+      dependencies: [
+        "Common", "P4Lang", "P4Compiler", "P4Runtime", "Macros",
+        .product(name: "ArgumentParser", package: "swift-argument-parser"),
+      ],
+      swiftSettings: [.enableExperimentalFeature("CodeItemMacros")],
+    ),
     .testTarget(
       name: "Tests",
-            dependencies: ["P4Compiler", "P4Runtime", "P4Lang", "Macros", "TreeSitterExtensions", "Common"],
+      dependencies: [
+        "P4Compiler", "P4Runtime", "P4Lang", "Macros", "TreeSitterExtensions", "Common",
+      ],
       swiftSettings: [.enableExperimentalFeature("CodeItemMacros")],
     ),
   ],

README.md

@@ -90,6 +90,7 @@ where `<component>` is one of:
 4. `common`: For any Swift-based components common to the entire project (and macros).
 5. `documentation`: For any documentation updates.
 6. `testing`: For Swift-based tests.
+7. `cli`: For Cli components.
 
 where `<subcomponent>` can be more free-form and `<change>` is a pithy description of the changes in the commit.
 

Sources/Cli/main.swift

@@ -0,0 +1,27 @@
+// p4rse, Copyright 2026, Will Hawkins
+//
+// This file is part of p4rse.
+//
+// This file is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+import ArgumentParser
+import Darwin
+import Common
+@main
+struct Cli: ParsableCommand {
+    public func run() throws {
+      let e = ErrorWithLocation(sourceLocation: SourceLocation(1, 5), withError: "Testing")
+      print(e.format())
+    }
+}