What is the difference between a wrapper, a binding, and a port?

Question

In a software portability context, what is the difference between these three concepts?

For example, I want to use the ncurses library, the original ncurses library is written in C, but my application is being written in C++, and then I found "ncurses wrapper", "bindings to ncurses", and "ncurses port". Which one should I use?

What are the pros and cons of each one?

Answer 1

A wrapper is a bit of code that sits on top of other code to recycle it's functionality but with a different interface. This usually implies an interface written in the same language. It should also be noted that sometimes people will say wrapper when what they technically mean is a binding (myself included).

Pros:

• It's in the same language as the original
• Wrappers enhance or reuse functionality without needing a full rewrite.
• Relatively quick to accomplish
• Trivial updates when the source library changes. You'll probably only need to bind new functions unless they broke backwards compatibility by changing expected input/outputs of functions/classes.

Cons:

• Wrapping an entire library can be extremely repetitive

A binding is another bit of code that sits on top of other code to recycle it's functionality except this time bindings are written in a language different than the thing they bind. A notable example is PyQt which is the python binding for QT.

Pros:

• Bring functionality from another language into the language of your choice.
• Relatively fast in comparison to a port
• Same level of trivial changes are needed as in wrapping- You'll probably only need to wrap new functions/classes unless they broke backwards compatibility by changing expected input/outputs of functions/classes.

Cons:

• Just as repetitive as a wrapper
• You're probably taking a fairly large performance hit, especially any wrapper involving an interpreted language on either end

A Port is when you translate some code to work in a different environment. Common analogies include games that come out for say... XBox and are later released for PS3.

Pros:

• Gives you the opportunity to make improvements to the code base as you see inadequacies
• You'll be intimately familiar with HOW the code runs, not just what it does.

Cons:

• By far the lengthiest solution in terms of time/requires a complete rewrite
• You need to make sure that whatever functionality the source library needs in a language is available in your target port language or you'll end up wrapping needed functionality (and potentially defeating the purpose.)
• Every time the source library updates, you have to update too by translating whatever changes they made or risk falling behind.