erlang workshopdrammen
DESCRIPTION
Erlang workshop for Drammen Software meetupTRANSCRIPT
Erlang workshop
Reidar Sollid Erlang workshop in Drammen
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Erlang
• The world is concurrent • Things in the world don’t share state • Things communicate through messages • Things fail
- Joe Armstrong
Presentation Title - Classification
What is Erlang
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• Created and maintained by Ericsson (now open source) • Functional, single assignment, strict evaluation, dynamic typing • Actor model, concurrent oriented, fault tolerant, soft-real-time • Light weight processes that communicate using message passing
(You can have several processes in one OS/Java thread) • Erlang started life as modified prolog • Erlang shell, escript and compiled .beam bytecode
Presentation Title - Classification
What problem to solve
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What is Elixir
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1) A Ruby like language for the Erlang VM BEAM
2) Seamless Erlang integration: zero-penalty Erlang function calls (and vice versa)
3) Meta programming via macros and a first-class AST (Abstract syntax tree)
4) Polymorphism via protocols inspired by Clojure
Presentation Title - Classification
And this
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Presentation Title - Classification
Shared memory model
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Shared memory
Process thread
Process thread
Process thread
Presentation Title - Classification
Message passing
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Process thread
Process thread
Process thread
Presentation Title - Classification
Concurrency and shared memory model
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Atoms and variables
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• An atom is global constant starting with lower case char
• A variable starts with a capital char and is called a variable since it can be bound or unbound. Once the variable is bound it can never change.
Presentation Title - Classification
Pattern matching
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Pattern matching• Everything in Erlang is pattern matching • When assigning a variable, that is really
pattern matching
Loops
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No while or for loops ?
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Tail optimised recursion
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Presentation Title - Classification
Lambdas
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BIF (Built in Functions)
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OTP (Open Telecom Platform)
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1.Mostly used by finance sector, so it just called OTP now 2.Contains a set of behaviours
4.The standard Erlang/OTP behaviours are: 1.gen_server
1. For implementing the server of a client-server relation.
2.gen_fsm 1. For implementing finite state machines.
3.gen_event 1. For implementing event handling functionality.
4.supervisor 1. For implementing a supervisor in a supervision tree.
Rebar
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Rebar
• Rebar is an Erlang build tool that makes it easy to compile and test Erlang applications, port drivers and releases.
• Contains templates for OTP development
Presentation Title - Classification
Stickers ?
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