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John Lam's Blog


A recent interview with Anders Hejlsberg!

Anders Hejlsberg

I found this on Hacker News

  • His brother is one of the interviewers
  • They started programming 40 years ago in Copenhagen
  • Started using high school computer in the 1970s
  • Started by implementing a programming language, Turbo Pascal
  • Cut his teeth by adding extensions to existing language to make it useful
  • C# was first language designed from scratch
  • "You can always add but you can never take away"
  • The perfect programming language is one with no users(!)
  • V1.0 is the only greenfield
  • Game of learning to say no vs. yes
  • Language features asks come from people with an instance of a problem - he tries to find the class of problems that it belongs to
  • HTML is an incomprehensible mess :)
  • TypeScript was the first foray of a project that, from the onset was open source
  • Wanted Roslyn to be open source, but C# and .NET was not open source
  • Roslyn was not built as open source, was open sourced later
  • Open development - 2014 moved to GitHub - everything is on GitHub is the next step, e.g., design notes - close to users
  • Anders participates in C# design committee, but Mads has been running it for the last decade(!)
  • Multiple inheritence - usefulness does not outweigh the downsides of additional complexity
  • If he could change one thing in C# he would have nullability and value/reference types as orthogonal issues, e.g., you cannot have non-nullable reference types
  • Tony Hoare called inventing null his billion dollar mistake
  • Functional programming languages do not enable circular reference data types (e.g., double-linked list or trees with back-pointers)
  • Opting into nullability in specific areas
  • Don Syme did most of the implementation of generics in .NET 2.0
  • He regrets dynamic in C# 4.0
  • He likes the work done in C# 5.0 for async/await
  • TypeScript - how solve the nullability problem. He is very happy with that result.
  • Turbo Pascal 1.0 symbol table was a linked list(!)
  • He read Algorithms + Data Structures = Programs by Niklas Wirth - learned about hash tables and then reimplemented the symbol table in Turbo Pascal 2.0 using them local copy in case this disappears from the web
  • He learned by trial and error without formal background

I like it when things that I read and don't agree with get me thinking about an idea. This post by David Perell spent some time rattling around in my subconscious:

I didn't agree with it because almost all software that I use today requires me to Google something to figure out an obscure feature - there are always obscure features especially in software that I don't use all the time. If I don't know how to do something already using the UI, I would immediately Google it and follow the directions on how to accomplish the task.

I was out riding my bike today, and listening to Neal Stephenson being interviewed by Lex Fridman. During the conversation they talked about Google and search. The idea that popped into my head then was that UI is great for idiomatic operations and search is great for everything else.

The example in my head was VS Code. The idiomatic operations are provided by the UI, e.g., vi keybindings for navigating a document, tabs for managing multiple documents, a file explorer for viewing the contents of your project, a debugging tab for viewing the state of variables in the debugger etc. IMHO the real innovation in VS Code is the command palette which lets you search for the command that you want - this avoids over-complicating the UI with endless toolbars. VS Code users quickly learn to use the fuzzy search in the command palette to find the command that they are looking for. They even have the ability to bind those commands to a custom keybinding to turn it into an idiomatic operation if they use that command often enough.

I think this strikes the right balance between a rich featureset and a simple, idiomatic UI. Unfortunately, it seems that in our attempt to simplify everything for the novice user, we have wound up with UIs that have way too many layers of UI (I'm looking at you, Microsoft Teams).

I wonder what a better experience for search would be on mobile though? A command palette is a lot more difficult to use on a phone. #