firebase-ios-sdk/Firestore/Swift/Source/SwiftAPI/Pipeline/Expressions/FunctionExpressions/RandomExpression.swift

// Copyright 2025 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
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///
/// A `RandomExpression` is a `FunctionExpression` that generates a random floating-point
/// number between 0.0 (inclusive) and 1.0 (exclusive).
///
/// This expression is useful when you need to introduce a random value into a pipeline,
/// for example, to randomly sample a subset of documents.
///
/// Example of using `RandomExpression` to sample documents:
/// ```swift
/// // Create a query to sample approximately 10% of the documents in a collection
/// firestore.pipeline()
///   .collection("users")
///   .where(RandomExpression().lessThan(0.1))
/// ```
public class RandomExpression: FunctionExpression, @unchecked Sendable {
  /// Creates a new `RandomExpression` that generates a random number.
  public init() {
    super.init("rand", [])
  }
}