What's Bad About Julia - Addressing Fundamental Issues

Explore fundamental issues in the Julia programming language and potential solutions in this JuliaCon 2019 talk. Delve into topics such as modularity, types, and opaque method specificity rules. Learn about widely known challenges in Julia, including handling the Missing type and compiler problems with certain type definitions. Gain insights into the first and second rules of method specification, and understand why the second rule poses difficulties. Examine examples of specificity problems and their implications. Conclude with a Q&A session addressing circular specifications, stricter rules, method writing, prioritization of fixes, recent improvements, and the impact of unions on the language.

Welcome!.
Purpose of the talk.
Users should speak about their problems with Julia.
Widely know bad things about Julia.
Is the presented list of problems exhaustive?.
Why some problems were chosen as the main topics of this talk.
Modularity.
Example of modules we want to keep separate.
Problem with isolating constructors.
Types.
How to handle Missing type in code.
Compiler problem with some types definitions.
Opaque method specificity rules.
First, the most important rule of method specification.
Second "rule" of method specification.
Why we have a problem with second "rule".
Problem of "X is more specific that Y. Example 1.
Problem of "X is more specific that Y. Example 2.
Conclusions.
Q&A: What would happens in the case of circular specification?.
Q&A: What would happens if specification rules were stricter?.
Q&A: How many methods need to be write to allow to make specifications rules stricter? (Follow up to previous question.).
Q&A: What is the order of priority of fixing well know bad things in Julia?.
Q&A: What is last big Julia's problem that was fixed, according to Jeff Bezanson?.
Q&A: How much better or worse world be without unions?.