  This paper presents an AI-assisted programming tool called Copilot for Xcode
for program composition and design to support human software developers. By
seamlessly integrating cloud-based Large Language Models (LLM) with Apple's
local development environment, Xcode, this tool enhances productivity and
unleashes creativity for software development in Apple software ecosystem
(e.g., iOS apps, macOS). Leveraging advanced natural language processing (NLP)
techniques, Copilot for Xcode effectively processes source code tokens and
patterns within code repositories, enabling features such as code generation,
autocompletion, documentation, and error detection. Software developers can
also query and make "small" decisions for program composition, some of which
can be made simultaneously, and this is facilitated through prompt engineering
in a chat interface of Copilot for Xcode. Finally, we present simple case
studies as evidence of the effectiveness of utilizing NLP in Xcode to prompt
popular LLM services like OpenAI ChatGPT for program composition and design.
