build(nix/flake): adding the flake.nix

flake.nix

@@ -0,0 +1,75 @@
+{
+  description = "Shell for DrQuine project";
+
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+  inputs.flake-utils.url = "github:numtide/flake-utils";
+
+  outputs =
+    {
+      self,
+      nixpkgs,
+      flake-utils,
+    }:
+    flake-utils.lib.eachDefaultSystem (
+      system:
+      let
+        pkgs = import nixpkgs {
+          inherit system;
+        };
+        tmux-setup = pkgs.writeShellScriptBin "tmux-setup" ''
+          #!/usr/bin/env sh
+          SESSION="libasm"
+          DIR=$(git rev-parse --show-toplevel 2>/dev/null || pwd)
+          if ! tmux has-session -t $SESSION 2>/dev/null; then
+            tmux new-session -d -s $SESSION -c "$DIR" -n dev
+            tmux send-keys -t $SESSION:0 'vim' C-m
+            tmux split-window -h -p 30 -t $SESSION:0 -c "$DIR"
+            tmux send-keys -t $SESSION:0.1 'exec zsh' C-m
+            tmux new-window -t $SESSION:1 -n git -c "$DIR"
+            tmux send-keys -t $SESSION:1 'lazygit' C-m
+          fi
+          tmux select-window -t $SESSION:0
+          tmux select-pane -t $SESSION:0.0
+          tmux attach -t $SESSION
+        '';
+      in
+      {
+        devShells.default = pkgs.mkShell {
+          name = "libasm-42";
+          buildInputs =
+            with pkgs;
+            [
+              tmux-setup
+              nasm
+              gcc
+              clang
+              clang-tools
+              binutils
+              gnumake
+              lldb
+              coreutils
+              xxd
+              valgrind
+              clang-tools
+              asm-lsp
+            ]
+            ++ (
+              if pkgs.stdenv.isLinux then
+                [
+                  strace
+                  valgrind
+                ]
+              else
+                [ ]
+            );
+
+          shellHook = ''
+              export AS=nasm
+              export CC='clang'
+              export ASM_LSP_CONFIG="$(pwd)/asm-lsp.toml"
+              printf "\n\033[0;90mASM env loaded for: \033[38;5;220m${system}\033[0m\n"
+            '';
+        };
+      }
+    );
+}