Add example

examples/merge_file.py

@@ -0,0 +1,38 @@
+"""Merge three versions of a file: mine, base, and theirs.
+
+A trivial version of git merge-file (https://git-scm.com/docs/git-merge-file).
+
+Run it with:
+    uv run --directory reconcile-python \
+        python ../examples/merge_file.py my.txt base.txt their.txt [output.txt]
+"""
+
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+from reconcile_text import reconcile
+
+
+def main() -> None:
+    args = sys.argv[1:]
+
+    if len(args) < 3 or len(args) > 4:
+        print("Usage: merge_file.py <mine> <base> <theirs> [output]", file=sys.stderr)
+        sys.exit(1)
+
+    mine = Path(args[0]).read_text()
+    base = Path(args[1]).read_text()
+    theirs = Path(args[2]).read_text()
+
+    result = reconcile(base, mine, theirs)
+
+    if len(args) == 4:
+        Path(args[3]).write_text(result["text"])
+    else:
+        print(result["text"], end="")
+
+
+if __name__ == "__main__":
+    main()