> mostly due to various technical reason Could you please go into those? I'd like to understand why unwinding the stack is costlier than returning from a function.
On Saturday, May 7, 2016 at 8:38:03 AM UTC-4, Yichao Yu wrote: > > On Sat, May 7, 2016 at 6:58 AM, Ben Ward <axolotl...@gmail.com > <javascript:>> wrote: > > Hi, > > > > I have a question which may be laughable to CS people (be gentle, I'm a > > Biologist), but we know from guidelines that Julia performs best, when a > > method always returns the same type of value. > > So the Julia type inference knows - ok, use this method with an Int, it > will > > always return a bool say. How does throws fit into this? To my mind this > > means the method used with an Int may return a bool, but it also may > result > > in a type of (e.g.) ArgumentError getting thrown. So how do throws in > > functions affect performance and julian's ability to infer types and > > optimise code (if at all?)? > > While throwing or catching an error itself is slow (mostly due to > various technical reason) they shouldn't affect type stability. > > The type inference currently do not reason about what type of > exception can be thrown and even if it does, this won't affect what we > usually call the type stability of a function since it is only about > the **return type** of a function and throwing an error is not return > (in the sense that `a = cond ? error() : 1`, if the next statement is > executed, a is always a `Int`). > > > > > Thanks, > > Ben W. >
