Find HS Code and trade information for closures

Closures

Closures are a fundamental concept in many programming languages, representing a powerful mechanism for creating stateful functions and encapsulating behavior. They are primarily associated with functional programming paradigms but are often found in other language styles as well.

Core Concept

A closure is a function bundled together with its surrounding state (lexical environment). This means a closure "remembers" the variables and values from the scope in which it was created, even after that scope has finished executing. Crucially, this isn't simply copying the values; the closure retains access to the original variables.

Material (Implementation)

Closures are typically implemented using function objects or similar constructs within the language's runtime environment. The specific mechanism varies, but generally involves:

• Function Object: The closure is represented as a function object.
• Lexical Environment: A record of the variables and their values in the scope where the closure was defined. This environment is maintained even after the outer function has returned.
• Reference to Environment: The function object holds a reference to the lexical environment, allowing it to access and modify those captured variables.

Purpose

• State Persistence: Closures allow functions to maintain state between invocations without relying on global variables or mutable objects.
• Data Encapsulation: They can be used to create private variables and methods, similar to the concept of encapsulation in object-oriented programming.
• Partial Application & Currying: Closures facilitate partial application, where a function is called with some arguments, returning a new function that expects the remaining arguments. Currying is a more extreme form of this, where a function is broken down into a series of functions, each taking a single argument.
• Event Handling & Callbacks: Closures are commonly used in event handling systems to associate a function with a specific event and retain access to relevant data.

Function

• Capturing Variables: The core function of a closure is to "capture" variables from its surrounding scope. These variables can be accessed and modified within the closure.
• Returning a Function: Closures are often created by functions that return other functions. The returned function is the closure itself.
• Maintaining State: The closure preserves the state of the captured variables between calls.

Usage Scenarios

• Event Listeners: Associating a function with a DOM event and retaining access to the element and any relevant data.
• Asynchronous Operations: Handling results from asynchronous operations, preserving the context in which the operation was initiated.
• Iterators & Generators: Creating iterators and generators that maintain state between calls to next().
• Functional Programming: Implementing higher-order functions, partial application, and currying.
• Module Creation: Simulating private variables and methods within a module.

Common Types/Variations

• Lexical Scoping: The most common type, where closures capture variables based on their position in the source code.
• Dynamic Scoping: (Less common) Closures capture variables based on the call stack at the time of creation.
• Non-Capturing Closures: Closures that do not capture any variables from their surrounding scope. These are less common but can be useful in certain situations.
• Self-Invoking Closures (IIFEs - Immediately Invoked Function Expressions): Closures that are executed immediately after they are defined. Often used to create a private scope and avoid polluting the global namespace.

Based on the provided information, the declared goods "closures" can be classified under the following HS codes:

• 3923500000: This HS code falls under Chapter 39, which covers plastics and articles thereof. Specifically, it relates to articles for the conveyance or packing of goods, of plastics; stoppers, lids, caps and other closures. This would include various types of plastic closures used for packaging.
• 3923900080: This HS code also falls under Chapter 39, plastics and articles thereof. It covers articles for the conveyance or packing of goods, of plastics; stoppers, lids, caps and other closures, but categorized as 'Other Other'. This is a more general classification for plastic closures not specifically detailed in 3923500000.

According to the provided reference material, the HS code options related to 'closures' are limited, with only the following 2 found.

Regarding HS code 3923500000 and 3923900080, the applicable tax rates are as follows: a basic tariff of 5.3% and 3.0% respectively, with an additional surcharge of 25.0% for both. Furthermore, after April 2, 2025, the additional surcharge will increase to 30.0% for both HS codes, resulting in a total tariff of 60.3% and 58.0% respectively.