Erlang (programming language)/Tutorials: Difference between revisions
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==History== | ==History== | ||
The erlang language was first written in prolog by Joe Armstrong. Ref:audio interview with Joe Armstrong from (http://www.se-radio.net). Joe is a known fan of prolog and borrowed much syntax from prolog in the design of erlang. | The erlang language was first written in prolog by Joe Armstrong. Ref:audio interview with Joe Armstrong from (http://www.se-radio.net). Joe is a known fan of prolog and borrowed much syntax from prolog in the design of erlang. This first prolog version of erlang was slow and motivated the creation of a virtual machine. Later an emulator called the BEAM was written in C and is about 200,000 lines of C code. It is thought that erlang is short for "Ericsson Language", due to its place of birth. | ||
==Overview== | ==Overview== | ||
Revision as of 15:17, 12 May 2009
Erlang Language Programming Tutorials
History
The erlang language was first written in prolog by Joe Armstrong. Ref:audio interview with Joe Armstrong from (http://www.se-radio.net). Joe is a known fan of prolog and borrowed much syntax from prolog in the design of erlang. This first prolog version of erlang was slow and motivated the creation of a virtual machine. Later an emulator called the BEAM was written in C and is about 200,000 lines of C code. It is thought that erlang is short for "Ericsson Language", due to its place of birth.
Overview
Basic Erlang
- Get to know the Command Line
- Terms
- Pattern Matching
- Expressions
- Functions
- Guards
- Modules
- Errors - working with exceptions
- Processes and Messages
- Trapping Exit Signals
- Timeouts
- Macros
- Techniques of Recursion
- List Comprehensions
- List Comments
Syntax
Functions are defined by the domain of the arguments and the number of arguemnts. A function ends with a period. A function over a particular domain of values is separated by a semicolon. The arrow shows how a particular function of a particular value or variable maps to an output.
fact(0) -> 1;
fact(N) when is_integer(N) ->
fact(N-1)*N.
Simple Types
Basic types in erlang include:
- atom - alice
- integer - 3
- float - 3.1415
- pid - a process id number <0.42.0>
- list - [ things in square brackets ]
- tuple - { things in curly braces }
Advanced Types
- binary - a binary data block, <<42>>
- function - a function, F = fun(X) -> X*X end.
- port - a path for data to flow to the outside world
- reference - a unique id over all processes
- record - the standard erlang data structure
Modules
Adding/Replacing Modules
Erlang is picky about updating or replacing modules of the same name. You should completely remove the old module code from the directory tree, not just rename the containing directory.
Popular Modules
Nonstandard Modules
- Eunit Unit Testing Module
Object Oriented Programming with erlang
Functional Programming with erlang
- Fun with folding
- Iterator
- Simplify Numeric Types (auto-demotion of numerical types)
Example programs
- Hello World (Serial)
- Hello World (parallel)
- Prime Sieve with Linda
- Autonomous Agents in Erlang -- def: Autonomous Agent.
Advanced OTP
Databases
Mnesia
Advanced Erlang
Projects using erlang
- CouchDB - a scalable database for Apache
- Wings3D - a 3-D editor