Parsing is often deeply recursive and in some languages, throwing an exception will automatically unwind the stack until it finds a handler. As well as explicit

Parsing is often deeply recursive and in some languages, throwing an exception will automatically unwind the stack until it finds a handler. As well as explicitly giving you a good path and a bad path (as someone pointed out upthread) this can (again, in some languages) save a ton of repeated special case code in your parsing routines. Some languages or libraries are explicitly designed to use exceptions for flow control some strongly discourage this. Apple's ObjC error handling guide for example contains this stricture but also calls out parsing as an example of when you should do it. C.A.R 'null pointer' Hoare considered exceptions a blight on the earth that would lead to us accidentally nuking ourselves, so there's a spectrum of opinions available here.