[Client] add swift client

.gitignore

@@ -24,6 +24,8 @@ backend/.env
 /result-*
 clients/haskell/result
 clients/haskell/dist-newstyle
+clients/swift/*.out
+clients/swift/**/*/xcuserdata
 # dev
 bacon.toml
 docker-compose/localstack/export_cyphers.sh
@@ -34,4 +36,4 @@ test_logs
 .cargo
 # pre-commit config
 .pre-commit-config.yaml
-.cargo
+.cargo

clients/swift/Config.xcconfig

@@ -0,0 +1,25 @@
+//
+//  Config.xcconfig
+//  swift
+//
+//  Created by naman agarwal on 03/08/24.
+//
+
+// Configuration settings file format documentation can be found at:
+// https://help.apple.com/xcode/#/dev745c5c974
+
+// Change env manually
+// SUPERPOSITION_LIB_PATH=$(SRCROOT)/../../target/debug
+// SUPERPOSITION_INCLUDE_PATH=$(SRCROOT)/../../headers
+
+// Library Search Paths
+LIBRARY_SEARCH_PATHS = $(inherited) $(SUPERPOSITION_LIB_PATH)
+
+// Add your header search paths
+HEADER_SEARCH_PATHS = $(inherited) $(SUPERPOSITION_INCLUDE_PATH)
+
+// Linker Flags
+OTHER_LDFLAGS = $(inherited) -lcac_client -lexperimentation_client
+
+// Bridging Header
+SWIFT_OBJC_BRIDGING_HEADER = $(SRCROOT)/swift/Bridging-Header.h

clients/swift/README.md

@@ -0,0 +1,23 @@
+## CAC and Experimentation clients in `Swift`
+
+- ## Walkthrough
+    - Create bridging file for each module
+    - add the `#include` statement for the C header file
+    - `using nix`: use `swiftc` to compile modules using `-L`, `-l`, `I` and `-import-objc-header` flags to specify object files search dir, object-module name, header search path and bridging file path respectively. (checkout : [default.nix](default.nix))
+    - `using xcode`: create a command-line project in xcode and configure `-L`, `-l` and `-import-objc-header` flags using `Build Settings` in the GUI. Settings equivalent for each compiler flags (checkout : [Config](Config.xcconfig))
+
+        - `-L` : `LIBRARY_SEARCH_PATHS`
+        - `-l` : `OTHER_LDFLAGS`
+        - `-import-objc-header` : `SWIFT_OBJC_BRIDGING_HEADER`
+        - `I` : `HEADER_SEARCH_PATHS`
+
+- ## setup
+    - ### using nix :
+        1. cd to `clients/swift`
+        2. spawn devShell `nix develop .#swift`
+        3. run `compileTest`
+        4. use generated bins
+
+    - ### using xcode :
+        1. open project (`clients/swift`) in xcode
+        2. build & run the project

clients/swift/default.nix

@@ -0,0 +1,24 @@
+{
+  perSystem = { config, pkgs, self', lib, ... }: {
+    devShells.swift = let
+        compileTest = pkgs.writeShellScriptBin "compileTest" ''
+            swiftc \
+                swift/main.swift swift/cac.swift swift/exp.swift swift/types.swift swift/utils.swift swift/test.swift \
+                -L$SUPERPOSITION_LIB_PATH \
+                -I$SUPERPOSITION_INCLUDE_PATH \
+                -lcac_client \
+                -lexperimentation_client \
+                -import-objc-header swift/Bridging-Header.h \
+                -o test_client.out
+        '';
+    in
+    pkgs.mkShell {
+        name = "superposition-swift-clients";
+        buildInputs = with pkgs; [
+            swift
+            swiftPackages.Foundation
+            compileTest
+        ];
+    };
+  };
+}