PascalABC.NET

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PascalABC.NET
ParadigmMulti-paradigm: procedural, functional, object-oriented, generic
Designed byS.S. Mikhalkovich, Ivan Bondarev, A.V. Tkachuk, S.O. Ivanov
First appeared2002; 17 years ago (2002)
Stable release
3.4.0.1670 / 23 May 2018; 7 months ago (2018-05-23)
Typing disciplineStatic, partially inferred
Implementation languagePascalABC.NET
OSCross-platform
LicenseLGPLv3
Filename extensions.pas
Websitepascalabc.net/en/
Influenced by
Delphi, Pascal, C#, Python

PascalABC.NET is a Pascal programming language that implements classic Pascal, most Delphi language features, as well as a number of their own extensions. It is implemented on the .NET Framework platform and contains all the modern language features: classes, operator overloading, interfaces, exception handling, generic classes and routines, garbage collection, lambda expressions, parallel programming tools (OpenMP only as of 2016).

PascalABC.NET is also a simple and powerful integrated development environment with integrated debugger, IntelliSense system, form designer, code templates and code auto-formatting. Command-line PascalABC.NET compiler is also available on Linux and MacOS (under Mono).[1]

PascalABC.NET is popular in Russian schools and universities. In Southern Federal University, it is used as the main language for teaching students of Information technology in the course "Fundamentals of programming" and for teaching children in one of the largest computer schools in Russia.

Key features of PascalABC.NET[edit]

Pascal language extensions[edit]

  • Operators += -= *= /=
  • in-block variable definitions
  • Variable declaration in for loop header
  • Variable declaration with initialization (var n: integer := 10;)
  • Variable type deduction (var x := 1;)
  • foreach
  • Routines with a variable number of parameters
  • set of any type (set of integer)
  • Methods in records
  • Methods defined in class declaration
  • Simplified syntax of units
  • Keyword new (invoking a constructor)
  • Field initializers
  • Operator overloading
  • Static constructors
  • Directives OpenMP
  • case for strings
  • function type syntax T->T
  • tuple type syntax (T1,T2)
  • yield and yield sequence
  • pattern matching

System units[edit]

Most units are focused on education:

  • Raster graphics units GraphABC (based on Windows Forms), GraphWPF (based on WPF)
  • Vector graphics units ABCObjects (based on Windows Forms), WPFObjects (based on WPF)
  • 3D graphics & animation unit Graph3D (based on the Helix Toolkit library)
  • Unit FormsABC to create simple windows application without form designer
  • Units-executors Robot and Drawman (school computer science)

Samples[edit]

1. Swap the first and second halves of an array[edit]

begin
  var a := ArrGen(10,i->2*i+1);
  a.Println;
  Assert(a.Length mod 2 = 0);
  var n := a.Length div 2;
  a := a[n:] + a[:n];
  a.Println; 
end.

2. 100![edit]

begin
  var p: BigInteger := 1;
  for var i:=1 to 100 do
    p := p * i;
  Println(p);
end.

3. Greater common divisor of two integers[edit]

begin
  var (a, b) := ReadInteger2;
  while b > 0 do
    (a, b) := (b, a mod b);
  var GCD := a;
  GCD.Print;
end.

4. Display all Fibonacci numbers less than 1000[edit]

begin
  SeqWhile(1,1,(x,y)->x+y,x->x<1000).Print;
end.

5. Word frequence dictionary for a file[edit]

begin
  var d := new Dictionary<string,integer>;
  foreach var s in ReadLines('words.txt') do
    foreach var word in s.ToWords do
      d[word] := d.Get(word) + 1;
  d.Print(NewLine);
end.

5а. Word frequency dictionary for a file. Solution in functional style[edit]

begin
  ReadLines('words.txt').SelectMany(s->s.ToWords()).GroupBy(v->v).ToDictionary(x->x.Key,x->x.Count()).Print(NewLine);
end.

6. Parallel matrix multiplication using OpenMP directives[edit]

procedure Mult(a,b,c: array [,] of real; n: integer);
begin
  {$omp parallel for}
  for var i:=0 to n-1 do
    for var j:=0 to n-1 do
    begin  
       var cc := 0.0;
       for var l:=0 to n-1 do
          cc += a[i,l]*b[l,j];
       c[i,j] := cc;   
    end;
end;
 
const n = 1000;
 
begin
  var a := MatrixRandomReal(n,n,1,1.1);
  var b := MatrixRandomReal(n,n,1,1.1);
  var c := new real[n,n];
  Mult(a,b,c,n);
  writeln(MillisecondsDelta/1000);
end.

See also[edit]

References[edit]

External links[edit]