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Haskell Evaluation

Oct 21, 2014 · 3 min read · haskell programming

Conditional evaluation -- file: ch02/myDrop.hs myDrop n xs = if n <= 0 || null xs then xs else myDrop (n - 1) (tail xs) The if keyword introduces an expression that has three components. An expression of type Bool, immediately following the if. We refer to this as a predicate. A then keyword, followed by anot…

Haskell - Functions, Overloading, Pattern Matching, Variables

Oct 20, 2014 · 7 min read · haskell programming

III. Functions Function application is left associative The expression a b c d is equivalent to (((a b) c) d) If we want to use one expression as an argument to another, we have to use explicit parentheses to tell the parser what we really mean Defining and calling functions is simple add a b = a + b ad…

Haskell - Expressions, Basic Types, Composite Data Types

Oct 19, 2014 · 5 min read · haskell programming

Every expression and function in Haskell has a type. Types in Haskell are: Strong Static Can be automatically inferred. True has the type Bool 'foo' is of type String 1 has type Num Type are important for abstraction. To add meaning to some bytes. The meaning cannot change after the type has been defined. The be…

Haskell - Introducere

Oct 18, 2014 · 3 min read · haskell programming

Haskell e un limbaj de progamare functionala, spre deosebire de C/C++, Visual Basic, Java care sunt imperative.Programarea functionala poate fi vazuta ca un stil de programare in care principala metoda de calcul o reprezinta aplicarea de functii asupra unor argumente. Numele de programare funcţională provine din faptu…

SONET/SDH

Jun 28, 2014 · 2 min read · ppp sonet sdh

SONET este un standard ANSI care detalieaza cum mai multe stream-uri de date, fiecare cu diverse viteze, pot fi multiplexate. SONET are definite mai multe nivele OC (Optical Carrier). America de Nord foloseste SONET. Ratele de transfer sunt: OC-1 = 51.85 Mbps OC-3 = 155.52 Mbps (3 x OC-1) OC-12 = 622.08 Mbps OC-24 = 1…

BGP/MPLS IP VPN p2

Jun 28, 2014 · 2 min read · mpls bgp vpn

1. Site-uri si CE-uri Din perspectiva unei retele backbone, un set de sisteme IP pot fi interpretate drept un "site". daca acele sisteme au o interconectivitate IP reciproca ce nu necesita o retea backbone. In general, un site va consta dintr-un set de sisteme care se afla in proximitate. Dar nu este universal valabil…

BGP/MPLS IP VPN

Jun 28, 2014 · 7 min read · mpls bgp networking

Un service provider se poate folosi de propria retea backbone pentru a furniza servicii IP VPN pentru clientii sai. Routerele clientilor (CE) transmit toate rutele catre provider pe routere PE. BGP este apoi folosit de catre Service Provider (SP) pentru a tine actualizate rutele cu alte routere PE care apartin unui VP…

GNS3 Again

Jun 26, 2014 · 3 min read

tap interfacesbridge interfacesvirtualbox setupIOS imagesASA imagesJuniper imagesVirtualBox guest 1. Install softwareapt-get install gns3 dynamips uml-utilities bridge-utils2. Apply dynamips permissions so that dynamips does not have to run with root privileges, and avoid this kind of issues.sudo setcap cap_dac_overri…