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Quick Start

This guide walks you through basic persistent ETS operations with shelf.

1. Add shelf to your project

Section titled “1. Add shelf to your project”
Terminal window
gleam add shelf

2. Open a persistent table

Section titled “2. Open a persistent table”
import gleam/dynamic/decode
import shelf/set


pub fn main() {
  // Open a persistent set — loads existing data from disk
  let assert Ok(table) =
    set.open(name: "users", path: "data/users.dets", base_directory: "/app/data", key: decode.string, value: decode.int)


  // Fast writes (to ETS)
  let assert Ok(Nil) = set.insert(into: table, key: "alice", value: 42)
  let assert Ok(Nil) = set.insert(into: table, key: "bob", value: 99)


  // Fast reads (from ETS)
  let assert Ok(42) = set.lookup(from: table, key: "alice")


  // Persist to disk when ready
  let assert Ok(Nil) = set.save(table)


  // Close auto-saves
  let assert Ok(Nil) = set.close(table)
}

On next startup, set.open automatically loads the saved data back into ETS. The decoders ensure that every entry loaded from disk matches the expected types — any corrupted or mistyped entries are caught at load time.

Next steps

Section titled “Next steps”