![]() ![]() Just entering a try block is not free either, as the previous state of the CPU’s memory registers needs to be saved as they may need to be recovered in case an exception was thrown. Based on this article, the largest performance cost in Java is caused by printing the stack trace of the exception, which is expensive because the running program has to inspect the source code from which it was compiled. In languages such as Java, throwing an exception can be hundreds of times slower than a regular return from a function. This may solve the issues with obfuscating code, but runs into the another problem: performance. If you do catch exceptions at their source, you get a less elegant version of Go’s error pattern. In this case, the catch block acts in effect as a goto statement, which are generally considered harmful (curiously, one of the few use cases that are considered acceptable for the keyword in C is cleanup after errors, as the language has no Golang-style defer statements). ![]() We’ve all seen long blocks of code wrapped in a single try - catch block. Even in the languages with Java-style checked exceptions that must be handled, it’s not always obvious where the error was thrown from, if it’s handled at a level different from its original call. Firstly, it can hide the error handling path from the programmer, particularly if catching exceptions is not mandatory, such as in Python. The exception model treats errors as special cases to be handled separately from the program’s regular flow of returning a value. Most languages use exceptions: a system where a thrown exception propagates through the call stack until the level where it’s handled in a try-catch block. How should a programming language treat errors? For example, a function that opens a file with a given name and reads it to a buffer could fail for many reasons: the file might not exist, the opening program might lack permissions to open it, or it could be too large to fit in the buffer.
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