Scala Design Patterns - Second Edition

Partial functions are not partially applied functions

There seems to be some confusion around what partial functions are and what they are not. It is important for you to understand that these functions are not partially applied functions. Partially applied functions are simply functions that might take multiple parameters and we've specified some of them and then they return functions with fewer parameters that we can specify. There is another term—curried functions—that is related to partially applied functions. In terms of functionality, they provide the same functionality. Let's see a quick example:

/**  * Note that these are not partially defined functions!  */object PartiallyAppliedFunctions {  val greaterOrEqual = (a: Int, b: Int) => ...