Add SFN Hello example

Author: shepazon

swift/example_code/sfn/hello/Package.swift

@@ -0,0 +1,47 @@
+// swift-tools-version: 5.9
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+//
+// (swift-tools-version has two lines here because it needs to be the first
+// line in the file, but it should also appear in the snippet below)
+//
+// snippet-start:[swift.sfn.hello.package]
+// swift-tools-version: 5.9
+//
+// The swift-tools-version declares the minimum version of Swift required to
+// build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "hello-sfn",
+    // Let Xcode know the minimum Apple platforms supported.
+    platforms: [
+        .macOS(.v13),
+        .iOS(.v15)
+    ],
+    dependencies: [
+        // Dependencies declare other packages that this package depends on.
+        .package(
+            url: "https://github.com/awslabs/aws-sdk-swift",
+            from: "1.0.0"),
+        .package(
+            url: "https://github.com/apple/swift-argument-parser.git",
+            branch: "main"
+        )
+    ],
+    targets: [
+        // Targets are the basic building blocks of a package, defining a module or a test suite.
+        // Targets can depend on other targets in this package and products
+        // from dependencies.
+        .executableTarget(
+            name: "hello-sfn",
+            dependencies: [
+                .product(name: "AWSSFN", package: "aws-sdk-swift"),
+                .product(name: "ArgumentParser", package: "swift-argument-parser")
+            ],
+            path: "Sources")
+
+    ]
+)
+// snippet-end:[swift.sfn.hello.package]

swift/example_code/sfn/hello/Sources/entry.swift

@@ -0,0 +1,72 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+//
+// snippet-start:[swift.sfn.hello]
+// An example that shows how to use the AWS SDK for Swift to perform a simple
+// operation using Amazon Elastic Compute Cloud (EC2).
+//
+
+import ArgumentParser
+import Foundation
+
+// snippet-start:[swift.sfn.import]
+import AWSSFN
+// snippet-end:[swift.sfn.import]
+
+struct ExampleCommand: ParsableCommand {
+    @Option(help: "The AWS Region to run AWS API calls in.")
+    var awsRegion = "us-east-1"
+
+    static var configuration = CommandConfiguration(
+        commandName: "hello-sfn",
+        abstract: """
+        Demonstrates a simple operation using AWS Step Functions.
+        """,
+        discussion: """
+        An example showing how to make a call to AWS Step Functions using the
+        AWS SDK for Swift.
+        """
+    )
+
+    /// Called by ``main()`` to run the bulk of the example.
+    func runAsync() async throws {
+        let sfnConfig = try await SFNClient.SFNClientConfiguration(region: awsRegion)
+        let sfnClient = SFNClient(config: sfnConfig)
+
+        do {
+            let output = try await sfnClient.listStateMachines(
+                input: ListStateMachinesInput(
+                    maxResults: 10
+                )
+            )
+
+            guard let stateMachines = output.stateMachines else {
+                print("*** No state machines found.")
+                return
+            }
+
+            print("Found \(stateMachines.count) state machines (capped to 10)...")
+            for machine in stateMachines {
+                print("    \(machine.name ?? "<unnamed>"): \(machine.stateMachineArn ?? "<unknown>")")
+            }
+        } catch {
+            print("*** Error fetching state machine list: \(error.localizedDescription)")
+        }
+    }
+}
+
+/// The program's asynchronous entry point.
+@main
+struct Main {
+    static func main() async {
+        let args = Array(CommandLine.arguments.dropFirst())
+
+        do {
+            let command = try ExampleCommand.parse(args)
+            try await command.runAsync()
+        } catch {
+            ExampleCommand.exit(withError: error)
+        }
+    }    
+}
+// snippet-end:[swift.sfn.hello]