First commit

.github/workflows/build.yml

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+name: build
+on: [push, pull_request]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ocaml/setup-ocaml@v2
+      - uses: ankane/setup-postgres@v1
+        with:
+          database: pgvector_ocaml_test
+          dev-files: true
+      - run: |
+          cd /tmp
+          git clone --branch v0.5.1 https://github.com/pgvector/pgvector.git
+          cd pgvector
+          make
+          sudo make install
+      - run: opam install postgresql
+      - run: opam exec -- dune exec ./example.exe

.gitignore

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+/_build/

LICENSE.txt

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+The MIT License (MIT)
+
+Copyright (c) 2023 Andrew Kane
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

README.md

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+# pgvector-ocaml
+
+[pgvector](https://github.com/pgvector/pgvector) examples for OCaml
+
+Supports [PostgreSQL-OCaml](https://github.com/mmottl/postgresql-ocaml)
+
+[![Build Status](https://github.com/pgvector/pgvector-ocaml/actions/workflows/build.yml/badge.svg?branch=master)](https://github.com/pgvector/pgvector-ocaml/actions)
+
+## Getting Started
+
+Follow the instructions for your database library:
+
+- [PostgreSQL-OCaml](#postgresql-ocaml)
+
+## PostgreSQL-OCaml
+
+Enable the extension
+
+```ocaml
+c#exec ~expect:[Command_ok]
+  "CREATE EXTENSION IF NOT EXISTS vector"
+```
+
+Create a table
+
+```ocaml
+c#exec ~expect:[Command_ok]
+  "CREATE TABLE items (id bigserial PRIMARY KEY, embedding vector(3))"
+```
+
+Insert vectors
+
+```ocaml
+c#exec ~expect:[Command_ok] ~params:[|"[1,1,1]"; "[2,2,2]"; "[1,1,2]"|]
+  "INSERT INTO items (embedding) VALUES ($1), ($2), ($3)"
+```
+
+Get the nearest neighbors
+
+```ocaml
+let result =
+  c#exec ~expect:[Tuples_ok] ~params:[|"[1,1,1]"|]
+    "SELECT * FROM items ORDER BY embedding <-> $1 LIMIT 5"
+in
+result#get_all_lst |> List.map (List.map print_endline)
+```
+
+Add an approximate index
+
+```ocaml
+c#exec ~expect:[Command_ok]
+  "CREATE INDEX ON items USING ivfflat (embedding vector_l2_ops) WITH (lists = 100)"
+(* or *)
+c#exec ~expect:[Command_ok]
+  "CREATE INDEX ON items USING hnsw (embedding vector_l2_ops)"
+```
+
+Use `vector_ip_ops` for inner product and `vector_cosine_ops` for cosine distance
+
+See a [full example](example.ocaml)
+
+## Contributing
+
+Everyone is encouraged to help improve this project. Here are a few ways you can help:
+
+- [Report bugs](https://github.com/pgvector/pgvector-ocaml/issues)
+- Fix bugs and [submit pull requests](https://github.com/pgvector/pgvector-ocaml/pulls)
+- Write, clarify, or fix documentation
+- Suggest or add new features
+
+To get started with development:
+
+```sh
+git clone https://github.com/pgvector/pgvector-ocaml.git
+cd pgvector-ocaml
+createdb pgvector_ocaml_test
+opam install postgresql
+opam exec -- dune exec ./example.exe
+```

dune

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+(executable
+ (name example)
+ (libraries postgresql))

dune-project

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+(lang dune 3.7)

example.ml

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+open Postgresql
+
+let () =
+  let conninfo = "postgresql://localhost/pgvector_ocaml_test" in
+  let c = new connection ~conninfo () in
+  c#set_notice_processing `Quiet ;
+  let _ = c#exec ~expect:[Command_ok] "CREATE EXTENSION IF NOT EXISTS vector" in
+  let _ = c#exec ~expect:[Command_ok] "DROP TABLE IF EXISTS items" in
+  let _ =
+    c#exec ~expect:[Command_ok]
+      "CREATE TABLE items (id bigserial PRIMARY KEY, embedding vector(3))"
+  in
+  let _ =
+    c#exec ~expect:[Command_ok]
+      ~params:[|"[1,1,1]"; "[2,2,2]"; "[1,1,2]"|]
+      "INSERT INTO items (embedding) VALUES ($1), ($2), ($3)"
+  in
+  let result =
+    c#exec ~expect:[Tuples_ok] ~params:[|"[1,1,1]"|]
+      "SELECT * FROM items ORDER BY embedding <-> $1 LIMIT 5"
+  in
+  let _ = result#get_all_lst |> List.map (List.map print_endline) in
+  let _ =
+    c#exec ~expect:[Command_ok]
+      "CREATE INDEX ON items USING hnsw (embedding vector_l2_ops)"
+  in
+  c#finish