• https://thakkarparth007.github.io/copilot-explorer/posts/copilot-internals (HN)
• Uses deprecated “insert mode” API
• Has prefix and suffix. Prefix is the meat. Suffix is just what follows from the current cursor, default to 15% of the prompt.
• For prefix, lots of logic for prioritizing the “wishlist” of what “elements” to include.
  • Often has other related content, e.g. with “Compare this snippet from …” or other stuff.
    • Logic for chunking other files into windows, ranked by similarity to current file.

{
  "prefix": "# Path: codeviz\\\\app.py\\n# Compare this snippet from codeviz\\\\predictions.py:\\n# import json\\n# import sys\\n# import time\\n# from manifest import Manifest\\n# \\n# sys.path.append(__file__ + \\"/..\\")\\n# from common import module_codes, module_deps, module_categories, data_dir, cur_dir\\n# \\n# gold_annots = json.loads(open(data_dir / \\"gold_annotations.js\\").read().replace(\\"let gold_annotations = \\", \\"\\"))\\n# \\n# M = Manifest(\\n#     client_name = \\"openai\\",\\n#     client_connection = open(cur_dir / \\".openai-api-key\\").read().strip(),\\n#     cache_name = \\"sqlite\\",\\n#     cache_connection = \\"codeviz_openai_cache.db\\",\\n#     engine = \\"code-davinci-002\\",\\n# )\\n# \\n# def predict_with_retries(*args, **kwargs):\\n#     for _ in range(5):\\n#         try:\\n#             return M.run(*args, **kwargs)\\n#         except Exception as e:\\n#             if \\"too many requests\\" in str(e).lower():\\n#                 print(\\"Too many requests, waiting 30 seconds...\\")\\n#                 time.sleep(30)\\n#                 continue\\n#             else:\\n#                 raise e\\n#     raise Exception(\\"Too many retries\\")\\n# \\n# def collect_module_prediction_context(module_id):\\n#     module_exports = module_deps[module_id][\\"exports\\"]\\n#     module_exports = [m for m in module_exports if m != \\"default\\" and \\"complex-export\\" not in m]\\n#     if len(module_exports) == 0:\\n#         module_exports = \\"\\"\\n#     else:\\n#         module_exports = \\"It exports the following symbols: \\" + \\", \\".join(module_exports)\\n#     \\n#     # get module snippet\\n#     module_code_snippet = module_codes[module_id]\\n#     # snip to first 50 lines:\\n#     module_code_snippet = module_code_snippet.split(\\"\\\\n\\")\\n#     if len(module_code_snippet) > 50:\\n#         module_code_snippet = \\"\\\\n\\".join(module_code_snippet[:50]) + \\"\\\\n...\\"\\n#     else:\\n#         module_code_snippet = \\"\\\\n\\".join(module_code_snippet)\\n#     \\n#     return {\\"exports\\": module_exports, \\"snippet\\": module_code_snippet}\\n# \\n# #### Name prediction ####\\n# \\n# def _get_prompt_for_module_name_prediction(module_id):\\n#     context = collect_module_prediction_context(module_id)\\n#     module_exports = context[\\"exports\\"]\\n#     module_code_snippet = context[\\"snippet\\"]\\n# \\n#     prompt = f\\"\\"\\"\\\\\\n# Consider the code snippet of an unmodule named.\\n# \\nimport json\\nfrom flask import Flask, render_template, request, send_from_directory\\nfrom common import *\\nfrom predictions import predict_snippet_description, predict_module_name\\n\\napp = Flask(__name__)\\n\\[email protected]('/')\\ndef home():\\n    return render_template('code-viz.html')\\n\\[email protected]('/data/<path:filename>')\\ndef get_data_files(filename):\\n    return send_from_directory(data_dir, filename)\\n\\[email protected]('/api/describe_snippet', methods=['POST'])\\ndef describe_snippet():\\n    module_id = request.json['module_id']\\n    module_name = request.json['module_name']\\n    snippet = request.json['snippet']\\n    description = predict_snippet_description(\\n        module_id,\\n        module_name,\\n        snippet,\\n    )\\n    return json.dumps({'description': description})\\n\\n# predict name of a module given its id\\[email protected]('/api/predict_module_name', methods=['POST'])\\ndef suggest_module_name():\\n    module_id = request.json['module_id']\\n    module_name = predict_module_name(module_id)\\n",
  "suffix": "if __name__ == '__main__':\\r\\n    app.run(debug=True)",
  "isFimEnabled": true,
  "promptElementRanges": [
    { "kind": "PathMarker", "start": 0, "end": 23 },
    { "kind": "SimilarFile", "start": 23, "end": 2219 },
    { "kind": "BeforeCursor", "start": 2219, "end": 3142 }
  ]
}

Expanded:

# Path: codeviz\\app.py
# Compare this snippet from codeviz\\predictions.py:
# import json
# import sys
# import time
# from manifest import Manifest
# 
# sys.path.append(__file__ + "/..")
# from common import module_codes, module_deps, module_categories, data_dir, cur_dir
# 
# gold_annots = json.loads(open(data_dir / "gold_annotations.js").read().replace("let gold_annotations = ", ""))
# 
# M = Manifest(
#     client_name = "openai",
#     client_connection = open(cur_dir / ".openai-api-key").read().strip(),
#     cache_name = "sqlite",
#     cache_connection = "codeviz_openai_cache.db",
#     engine = "code-davinci-002",
# )
# 
# def predict_with_retries(*args, **kwargs):
#     for _ in range(5):
#         try:
#             return M.run(*args, **kwargs)
#         except Exception as e:
#             if "too many requests" in str(e).lower():
#                 print("Too many requests, waiting 30 seconds...")
#                 time.sleep(30)
#                 continue
#             else:
#                 raise e
#     raise Exception("Too many retries")
# 
# def collect_module_prediction_context(module_id):
#     module_exports = module_deps[module_id]["exports"]
#     module_exports = [m for m in module_exports if m != "default" and "complex-export" not in m]
#     if len(module_exports) == 0:
#         module_exports = ""
#     else:
#         module_exports = "It exports the following symbols: " + ", ".join(module_exports)
#     
#     # get module snippet
#     module_code_snippet = module_codes[module_id]
#     # snip to first 50 lines:
#     module_code_snippet = module_code_snippet.split("\\n")
#     if len(module_code_snippet) > 50:
#         module_code_snippet = "\\n".join(module_code_snippet[:50]) + "\\n..."
#     else:
#         module_code_snippet = "\\n".join(module_code_snippet)
#     
#     return {"exports": module_exports, "snippet": module_code_snippet}
# 
# #### Name prediction ####
# 
# def _get_prompt_for_module_name_prediction(module_id):
#     context = collect_module_prediction_context(module_id)
#     module_exports = context["exports"]
#     module_code_snippet = context["snippet"]
# 
#     prompt = f"""\\
# Consider the code snippet of an unmodule named.
# 
import json
from flask import Flask, render_template, request, send_from_directory
from common import *
from predictions import predict_snippet_description, predict_module_name

app = Flask(__name__)

@app.route('/')
def home():
    return render_template('code-viz.html')

@app.route('/data/<path:filename>')
def get_data_files(filename):
    return send_from_directory(data_dir, filename)

@app.route('/api/describe_snippet', methods=['POST'])
def describe_snippet():
    module_id = request.json['module_id']
    module_name = request.json['module_name']
    snippet = request.json['snippet']
    description = predict_snippet_description(
        module_id,
        module_name,
        snippet,
    )
    return json.dumps({'description': description})

# predict name of a module given its id
@app.route('/api/predict_module_name', methods=['POST'])
def suggest_module_name():
    module_id = request.json['module_id']
    module_name = predict_module_name(module_id)