ADT vs. Exceptions in Programming

code

In programming, error management and handling unexpected situations play a key role. There are two main approaches to error handling: using ADT (Abstract Data Types) and using Exceptions. Both approaches have their advantages and disadvantages, and the choice between them depends on the requirements of a particular project, programming language, and team preferences.

What is ADT in the context of error handling?

Abstract Data Types (ADTs) in the context of error handling are usually special types such as Result or Option that explicitly encode the possibility of an error in a function signature.

An example in Rust:

rust
fn divide(a: f64, b: f64) -> Result {
if b == 0.0 {
Err(“Division by zero”.to_string()))
} else {
Ok(a / b)
}
}

In this example, the return type Result explicitly indicates that the function may terminate either successfully (Ok(f64)) or with an error (Err(String)). Thus, the compiler forces the programmer to handle possible errors.

Languages that support functional programming, such as Haskell or Scala, also use Either, Option, and similar constructs.

Advantages of ADT:

  • Explicit error management – errors are visible in the function signature, making the code more predictable.
  • Safety – the programmer is forced to handle possible errors, otherwise the code will not compile.
  • Ease of testing – functions using ADT are easier to test because they do not cause unexpected interruption of code execution.
  • Compatibility with functional programming – ADTs integrate well with map, flatMap, match and other functional operations.

Disadvantages of ADTs:

  • Increased code complexity – you must manually check each value, handle Ok and Err, which can lead to more complex logic.
  • Probability of error “leaking” – if the programmer forgets to process Err, the error may be unnoticeably passed on to the system.
  • Complexity in imperative languages – in languages such as Java or Python, using ADT requires additional wrappers and is not always convenient.
  • Exceptions as a way of handling errors

Exceptions are a mechanism to interrupt normal program execution when an error occurs and pass control to an exception handler.

An example in Python:

python
def divide(a: float, b: float) -> float:
If b == 0:
raise ValueError(“Division by zero”)
return a / b
try:
result = divide(10, 0)
except ValueError as e:
print(f “Error: {e}”)

In this example, if b == 0, raise ValueError is called, which automatically passes control to the except block.

Advantages of exceptions:

  • Code simplification – no need to return Result explicitly, you can just call functions and handle errors only where needed.
  • Multi-layer support – exceptions can be “thrown” through abstraction layers without changing function signatures.
  • Good support in OOP languages – most object-oriented languages (Java, Python, C#) have built-in exception mechanisms.

Disadvantages of exceptions:

  • Implicit error control – a function call can end with an exception even if it is not specified in the function signature.
  • Performance – exception handling is more expensive than ADT handling, especially in languages where exceptions are rarely used (e.g., C++).
  • Easy to ignore – programmers can forget to handle an exception, which can lead to unexpected failures.

When to use ADT and when to use exceptions?

Use ADT if:

  • You develop code in a functional style (Rust, Haskell, Scala).
  • You need strict error typing.
  • You want to avoid unexpected program crashes.

Use exceptions if:

  • You are working in an OOP language (Java, Python, C#).
  • Errors are truly exceptional situations and not part of the expected flow of execution.
  • It is important for you to write concise code with minimal explicit error checking.

Conclusion

The choice between ADT and exceptions depends on the project architecture and the peculiarities of the language you use. If your goal is strict error checking and explicit error representation, ADT (for example, Result and Option) will be the best choice. But if you are interested in code simplicity and natural integration with OOP, exceptions may be a more suitable tool.

The main thing is to apply the chosen approach consistently and not to mix them chaotically to avoid confusion in the code.