Dave Thomas - Programming Elixir 1.6

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1. Assignment:
   I Do Not Think It Means What You Think It Means.

I have always been fascinated with how changes in hardware affect howwe write software.

A couple of decades ago, memory was a very limited resource. It madesense back then for our software to take hold of some piece ofmemory and mutate it as necessary. However, allocating this memory andcleaning up after we no longer needed it was a very error-pronetask. Some memory was never freed; sometimes memory was allocated overanother structure, leading to faults. At the time, garbage collectionwas a known technique, but we needed faster CPUs in order to use it inour daily software and free ourselves from manual memorymanagement. That has happenedmost of our languages are nowgarbage-collected.

Today, a similar phenomenon is happening. Our CPUs are not getting anyfaster. Instead, our computers get more and more cores. This means new software needs to use as many cores as it can if it is to maximizeits use of the machine. This conflicts directly with how we currently writesoftware.

In fact, mutating our memory state actually slows down our softwarewhen many cores are involved. If you have four cores trying to accessand manipulate the same piece of memory, they can trip over eachother. This potentially corrupts memory unless some kind ofsynchronization is applied.

I quickly learned that applying this synchronization is manual, errorprone, and tiresome, and it hurts performance. I suddenly realized thats nothow I wanted to spend time writing software in the next years of mycareer, and I set out to study new languages and technologies.

It was on this quest that I fell in love with the Erlang virtualmachine and ecosystem.

In the Erlang VM, all code runs in tiny concurrent processes, each with its own state. Processes talk to each othervia messages. And since all communication happens by message-passing,exchanging messages between different machines on the same network ishandled transparently by the VM, making it a perfect environment forbuilding distributed software!

However, I felt there was still a gap in the Erlang ecosystem. I missedfirst-class support for some of the features I find necessary in mydaily workthings such as metaprogramming, polymorphism, andfirst-class tooling. From this need, Elixir was born.

Elixir is a pragmatic approach to functional programming. It valuesits functional foundations and it focuses on developerproductivity. Concurrency is the backbone of Elixir software. Asgarbage collection once freed developers from the shackles of memorymanagement, Elixir is here to free you from antiquated concurrencymechanisms and bring you joy when writing concurrent code.

A functional programming language lets us think in terms of functionsthat transform data. This transformation never mutates data. Instead,each application of a function potentially creates a new, freshversion of the data. This greatly reduces the need fordata-synchronization mechanisms.

Elixir also empowers developers by providing macros. Elixir code isnothing more than data, and therefore can be manipulated via macros likeany other value in the language.

Finally, object-oriented programmers will find many of themechanisms they consider essential to writing good software, such aspolymorphism, in Elixir.

All this is powered by the Erlang VM, a 20-year-old virtual machinebuilt from scratch to support robust, concurrent, and distributedsoftware. Elixir and the Erlang VM are going to change how you writesoftware and make you ready to tackle the upcoming years inprogramming.