PascalABC.NET

Key features of PascalABC.NET

Pascal language extensions

• 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
• array slices
• interpolated strings
• unpacking of parameters of lambda expressions into variables

System units

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

1. Swap the first and second halves of an array

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!

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

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

4. Display all Fibonacci numbers less than 1000

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

5. Word frequence dictionary for a file

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.PrintLines;
end.

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

begin
  ReadLines('words.txt').SelectMany(s->s.ToWords).GroupBy(v->v).EachCount.PrintLines;
end.

6. Parallel matrix multiplication using OpenMP directives

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);
  Println(MillisecondsDelta/1000);
end.

See also

• Object Pascal
• C#

References

External links

• Official website
• PascalABC.NET Github Repository