John Barnes Informatics

Reading, United Kingdom

John Barnes Informatics

Reading, United Kingdom
SEARCH FILTERS
Time filter
Source Type

Barnes J.,John Barnes Informatics
Ada User Journal | Year: 2010

Ada 95 has evolved as a language that passes the three tests and is clear about types, classes and inheritance. If a user accidentally adds a semicolon at the end of the first line, Ada fails to compile and the error is mechanically detected before it can do any harm. In C, it still compiles, a null statement is controlled by the condition and no error is shown at compile time and a runtime error is the result. C and C++ of widely used or classic languages are the only languages that completely fail to incorporate the only real knowledge the user have. The confusion between types and classes is a really sad thing about C++. Ada delivers reuse rather better than C++ by its cleaner rules for dispatching and its sharp distinction between a type and a set of types. It permits multiple inheritance in a controlled manner with no ad-hoc rules.


Barnes J.,John Barnes Informatics
Ada User Journal | Year: 2011

This is the first of a number of papers describing the rationale for Ada 2012. In due course it is anticipated that the papers will be combined (after appropriate reformatting and editing) into a single volume for formal publication. This first paper covers the background to the development of Ada 2012 and gives a brief overview of the main changes from Ada 2005. Later papers will then look at the changes in more detail. rationale, Ada 2012. © 2011 John Barnes Informatics.


Barnes J.,John Barnes Informatics
Ada User Journal | Year: 2013

This is the last of a number of papers describing the rationale for Ada 2012. In due course it is anticipated that the papers will be combined (after appropriate reformatting and editing) into a single volume for formal publication. This last paper summarizes a small number of general issues of importance to the user such as compatibility between Ada 2012 and Ada 2005. It also briefly revisits a number of problems that were considered for Ada 2005 but rejected for various reasons; the important ones have been solved in Ada 2012. Finally, it discusses a small number of corrections that have been found necessary since the standard was approved.


Barnes J.,John Barnes Informatics
Ada User Journal | Year: 2013

This paper describes various relatively minor improvements to the predefined library in Ada 2012. The major changes concerning the container library will be described in a later paper. © 2013 John Barnes Informatics.


Barnes J.,John Barnes Informatics
Ada User Journal | Year: 2016

This paper describes the rationale for the changes made to Ada 2012 as a consequence of a review carried out in 2015. © 2016 John Barnes Informatics.


Barnes J.,John Barnes Informatics
Ada User Journal | Year: 2012

This paper describes the introduction of more flexible forms of expressions in Ada 2012. There are four new forms of expressions. If expressions and case expressions define a value and closely resemble if statements and case statements. Quantified expressions take two forms using for all and for some to return a Boolean value. Finally, expression functions provide a simple means of parameterizing an expression without the formality of providing a function body. These more flexible forms of expressions will be found invaluable in formulating contracts such as preconditions. It is interesting to note that Ada now has conditional expressions over 50 years after their introduction in Algol 60.


Barnes J.,John Barnes Informatics
Ada User Journal | Year: 2012

This paper describes various improvements in a number of general areas in Ada 2012. There are some minor but perhaps surprising changes concerning matters such as the placement of pragmas and labels. There are important new features regarding indexing and accessing largely introduced to simplify iterating over containers. There are also a number of additional Restrictions identifiers many related to the introduction of aspect specifications. The functionality of access types and storage management is made more flexible by the introduction of subpools. Finally, a number of minor additions and corrections are made to a range of topics such as generics. © 2012 John Barnes Informatics.


Barnes J.,John Barnes Informatics
Ada User Journal | Year: 2012

This paper describes various improvements in the areas of structure and visibility for Ada 2012. Perhaps the most amazing change is that functions may now have parameters of all modes. In earlier versions of Ada, functions could only have parameters of mode in and so could not change variables explicitly passed as parameters; however, they could silently manipulate global variables in any way whatsoever. In order to ameliorate any risks of foolishness with this new freedom, there are new rules regarding order dependence. There are also important improvements to incomplete types which make them much more useful; these include completion by a private type, their use as parameters and a new form of generic parameter. Other improvements include a new form of use clause and changes to extended return statements. © 2012 John Barnes Informatics.

Loading John Barnes Informatics collaborators
Loading John Barnes Informatics collaborators