Download Beginning Haskell. a project-based approach by Mena A.S. PDF

By Mena A.S.

Show description

Read Online or Download Beginning Haskell. a project-based approach PDF

Best compilers books

Linkers & Loaders

No matter what your programming language, no matter what your platform, you most likely faucet into linker and loader capabilities forever. yet are you aware how one can use them to their maximum attainable virtue? in simple terms now, with the booklet of Linkers & Loaders, is there an authoritative ebook committed completely to those deep-seated compile-time and run-time methods.

Abstraktion - Einfuhrung in die Programmierung

"Die Macht der Abstraktion" ist eine Einführung in die Entwicklung von Programmen und die dazugehörigen formalen Grundlagen. Im Zentrum stehen Konstruktionsanleitungen, die die systematische Konstruktion von Programmen fördern, sowie Techniken zur Abstraktion, welche die Umsetzung der Konstruktionsanleitungen ermöglichen.

Einführung in die Constraint-Programmierung: Grundlagen, Methoden, Sprachen, Anwendungen

Die Constraint-Programmierung liefert Methoden zur effizienten Modellierung von Systemen oder zur L? sung von Problemen, f? r die nur unvollst? ndige Informationen vorliegen. Ebenso hilft sie kombinatorische Probleme zu l? sen oder komplexe Deduktionssysteme zu entwickeln. Dieses kompakte Lehrbuch f?

Lisp Lore: A Guide to Programming the Lisp Machine

This ebook had its genesis within the following piece of computing device mail: From allegra! joan-b Tue Dec 18 09:15:54 1984 To: sola! hjb topic: lispm Hank, i have been conversing with Mark Plotnik and invoice Gale approximately asking you to behavior a simple path on utilizing the lisp laptop. Mark, for example, would love to hide fundamentals just like the style process, and so on.

Extra resources for Beginning Haskell. a project-based approach

Example text

Let’s rewrite companyName: companyName :: Client -> Maybe String companyName client = case client of Company name _ _ _ -> Just name _ -> Nothing One interesting fact is that you can pattern match directly on let and where bindings. In that case you can only handle one pattern, but it is very useful when you know that only one kind of value can happen in a specific place. Let’s say you are sure at some point that the client you are working with is a company. Instead of the not very clear code: let name = match companyName client of Just n -> n You can write a much more concise version: let Just name = companyName client Constants are also patterns, which match the exact values written.

Thus, in many cases the code ends up with a collection of _ bindings, which are difficult to maintain. With a record, you can use a new pattern that resembles the building one: the constructor, plus a list of field name = pattern elements enclosed in brackets. You don’t need to include all the fields: only those for which you want to bind or match. You are even allowed to write an empty list of fields, as this example highlights: greet greet greet greet :: ClientR -> IndividualR { CompanyR { GovOrgR { String person = PersonR { firstName = fn } } = "Hi, " ++ fn clientRName = c } = "Hello, " ++ c } = "Welcome" There are two very interesting additions in GHC to record matching that encode very usual patterns, allowing for a lesser amount of boilerplate.

It wouldn’t make sense to add an entire new declaration, polluting your module. You already know a solution, which is to define the function inside a let or where block. FnsParams| [3,4,5] :{ let f x = x + 2 in map f [1,2,3] :} This solution is not completely satisfactory: Haskell encourages passing and returning functions, so with this design the code would be full of let blocks. Instead, Haskell includes anonymous functions. These are function bodies that are not given a name and that can be written anywhere in the code where a function is expected.

Download PDF sample

Rated 4.93 of 5 – based on 9 votes