eBook - Seeing this instead of the website you expected?
... already found in both web pages, and search that before I search the
list of URLs from the first web page.
But a programmer who is accustomed to thinking in terms of discretemathematical structures might immediately think of a different approach:
The URLs in a web page are a set. I'll read each web ...
Creating High-Performance Statically Type
... A typical Internet server finds itself in the middle of a virtual battleground, under constant
threat from worms, viruses and other malware seeking to subvert the original intentions
of the programmer. In particular, critical Internet servers such as OpenSSH, BIND and
Sendmail have had numerous secu ...
Creating high-performance, statically type
... majority of server implementations continue to be written unsafely and informally in C/C++.
In this dissertation we propose an architecture for constructing new implementations of standard Internet protocols which integrates mature formal methods not currently used in deployed
servers: (i) static ty ...
ANSI C Programming study guide
... The set of instructions that can be used to construct a program is called a programming
Programming is the process of writing instructions in a language that the computer can
respond to and that other programmers can understand.
When English phrases are used to describe an algorithm ...
Lecture09 - Electrical and Computer Engineering Department
... sort(x :: L) = insert(x, sort(L)).
Everything seems to make sense as long as insert does its job. We’ll assume that whenever the
number to be inserted is already in the list, then a new copy will be placed to the left of the one
already there. Now let’s define insert. Again, the basis case is easy. ...
Short Notes on Haskell and Functional Programming Languages
... principle is changing the contents of stored values (called “variables”). Functional languages have no storage, no statements. In functional languages no value can ever be changed, new values can only be built
from existing ones without changing them, this is what happens when expressions are evalua ...
... A polymorphic type is a type defined by a polymorphic type expression that consists of a
type constructor and type variables (‘a, ‘b, …). For example, the ‘a List type is specified
using type variables. Every instantiation of the type variables defines a concrete type.
... • The data type of an object determines what values
it can have and what operations can be performed
Data Types and Operations On Data
... A small company wants you to write a program to figure out the number of
boxes needed to ship book orders without wasting space. They have four types
of boxes: extra large, large, medium and small, which can hold 25, 15, 5 and 1
Announcements Python Why Python? What to do today
... Python is a dynamically typed language
A variable can hold values of any type
A variable can hold different types of values at different times
Use type(x) to find out the type of the value x at a given time
Use names of types for conversion, comparison
Data types for mCRL2
... Each product (i, j) is optionally labelled by a projection pr i,j . With this projection, the j’th
element of summation i can be obtained. If a projection label is left out, the corresponding
: is left out. If a summation i does not have any products, it is written as ci ?is ci instead of
ci ()?is c ...
... We could also use infinite lists of booleans to represent real numbers. This is the usual
representation of numbers. This representation also corresponds to sequences of intervals,
but it has bad programming properties. In this representation, if we know that a number is
very close to 1/2 but we do ...
... Variables can hold different types at different times
... Working with Different Data Types
Different data types behave differently when we combine them using arithmetic operators. Consider the
following expressions. What do you think Python will print?
... – Scheme, which we’ll work with later in the course as well, is
dynamically (rather than statically) typed
– C++ allows us to explore many type system issues
– Please take advantage of the on-line tutorial and reference
manual pages that are linked on the course web site
– As always, please ask us f ...
... table = [[m*n | n <- [2..]] | m <- [1..]]
(a) Describe the contents of table.
(b) What would hugs/ghci print out if you asked it to display all the values in table?
(c) Write a Haskell expression to extract the finite list [5,10,15,20] from table.
7. Our aim is to define a list datatype th ...
... However, ML does have updatable (assignable) reference types, so that in those
cases where destructive update is the most natural way to express an algorithm,
one can express it directly.
ML supports information hiding, so that one can implement a data type whose
representation is hidden by an inter ...
Vienna Development Method
The Vienna Development Method (VDM) is one of the longest-established formal methods for the development of computer-based systems. Originating in work done at IBM's Vienna Laboratory in the 1970s, it has grown to include a group of techniques and tools based on a formal specification language - the VDM Specification Language (VDM-SL). It has an extended form, VDM++, which supports the modeling of object-oriented and concurrent systems. Support for VDM includes commercial and academic tools for analyzing models, including support for testing and proving properties of models and generating program code from validated VDM models. There is a history of industrial usage of VDM and its tools and a growing body of research in the formalism has led to notable contributions to the engineering of critical systems, compilers, concurrent systems and in logic for computer science.