Inline functions
It’s considered best practice to divide your code into small functions, and rightfully so. However, every function call introduces a level of indirection and slight performance overhead. While insignificant individually, this overhead may stack up if the function is invoked millions of times. In some cases, such as within the Spring Framework, functions may be hundreds of lines long due to performance requirements, leading to a departure from the single responsibility principle.
Inline functions can enhance performance by reducing the overhead of function calls. When you call a regular function, the Kotlin compiler generates a function invocation, which entails pushing arguments onto the stack, jumping to the function code, executing it, and then returning. Inline functions replace the function call with the actual function body at compile time, eliminating this overhead.
When passing lambda expressions as arguments to higher-order functions in Kotlin...