paxCompiler/help/demo_eval_expression.htm
Dalibor Marković 9d0de424e8
Init
Signed-off-by: Dalibor Marković <dalibor31@gmail.com>
2024-07-06 22:28:12 +02:00

144 lines
5.0 KiB
HTML

<html>
<head>
<link rel=stylesheet type="text/css" href="styles.css">
</head>
<body>
<H2>
paxCompiler for Delphi. Evaluate expression.
</H2>
<hr>
<blockquote>
<pre>
<font color="blue"><b>unit</b></font> Unit1;
<font color="blue"><b>interface</b></font>
<font color="blue"><b>uses</b></font>
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, PaxCompiler;
<font color="blue"><b>type</b></font>
TForm1 = <font color="blue"><b>class</b></font>(TForm)
Button1: TButton;
Button2: TButton;
<font color="blue"><b>procedure</b></font> Button1Click(Sender: TObject);
<font color="blue"><b>procedure</b></font> Button2Click(Sender: TObject);
<font color="blue"><b>procedure</b></font> FormCreate(Sender: TObject);
<font color="blue"><b>private</b></font>
{ Private declarations }
arr_x, arr_y: <font color="blue"><b>array</b></font>[1..3] <font color="blue"><b>of</b></font> Double;
h_norm, h_x, h_y: Integer;
buff: <font color="blue"><b>array</b></font>[1..4096] <font color="blue"><b>of</b></font> Byte;
<font color="blue"><b>public</b></font>
{ Public declarations }
<font color="blue"><b>end</b></font>;
<font color="blue"><b>var</b></font>
Form1: TForm1;
<font color="blue"><b>implementation</b></font>
{$R *.dfm}
<font color="blue"><b>function</b></font> Norm(x, y: Double): Double;
<font color="blue"><b>begin</b></font>
result := Sqrt(x * x + y * y);
<font color="blue"><b>end</b></font>;
<font color="blue"><b>procedure</b></font> TForm1.Button1Click(Sender: TObject);
<font color="blue"><b>var</b></font>
PaxCompiler1: TPaxCompiler;
PaxPascalLanguage1: TPaxPascalLanguage;
PaxProgram1: TPaxProgram;
I: Integer;
<font color="blue"><b>begin</b></font>
PaxCompiler1 := TPaxCompiler.Create(<font color="blue"><b>nil</b></font>);
PaxPascalLanguage1 := TPaxPascalLanguage.Create(<font color="blue"><b>nil</b></font>);
PaxProgram1 := TPaxProgram.Create(<font color="blue"><b>nil</b></font>);
<font color="blue"><b>try</b></font>
PaxCompiler1.Reset;
PaxCompiler1.RegisterLanguage(PaxPascalLanguage1);
h_norm := PaxCompiler1.RegisterRoutine(0, <font color="Red">'Norm'</font>, _typeDOUBLE, _ccREGISTER);
PaxCompiler1.RegisterParameter(h_norm, _typeDOUBLE, Unassigned);
PaxCompiler1.RegisterParameter(h_norm, _typeDOUBLE, Unassigned);
h_x := PaxCompiler1.RegisterVariable(0, <font color="Red">'x'</font>, _typeDOUBLE);
h_y := PaxCompiler1.RegisterVariable(0, <font color="Red">'y'</font>, _typeDOUBLE);
<font color="blue"><b>if</b></font> PaxCompiler1.CompileExpression(<font color="Red">'Norm(x, y)'</font>, PaxProgram1) <font color="blue"><b>then</b></font>
<font color="blue"><b>begin</b></font>
PaxProgram1.SaveToBuff(buff);
ShowMessage(<font color="Red">'Compiled expression has been created!'</font>);
<font color="blue"><b>end</b></font>
<font color="blue"><b>else</b></font>
<font color="blue"><b>for</b></font> I:=0 <font color="blue"><b>to</b></font> PaxCompiler1.ErrorCount - 1 <font color="blue"><b>do</b></font>
ShowMessage(PaxCompiler1.ErrorMessage[I]);
<font color="blue"><b>finally</b></font>
PaxCompiler1.Free;
PaxPascalLanguage1.Free;
PaxProgram1.Free;
<font color="blue"><b>end</b></font>;
<font color="blue"><b>end</b></font>;
<font color="blue"><b>procedure</b></font> TForm1.Button2Click(Sender: TObject);
<font color="blue"><b>var</b></font>
PaxProgram1: TPaxProgram;
ResValue: Double;
I: Integer;
<font color="blue"><b>begin</b></font>
{$O-}
<font color="blue"><b>if</b></font> h_x <> 0 <font color="blue"><b>then</b></font>
<font color="blue"><b>begin</b></font>
PaxProgram1 := TPaxProgram.Create(<font color="blue"><b>nil</b></font>);
<font color="blue"><b>try</b></font>
PaxProgram1.LoadFromBuff(buff);
PaxProgram1.SetAddress(h_norm, @norm);
<font color="blue"><b>for</b></font> I:=1 <font color="blue"><b>to</b></font> 3 <font color="blue"><b>do</b></font>
<font color="blue"><b>begin</b></font>
PaxProgram1.SetAddress(h_x, @arr_x[I]);
PaxProgram1.SetAddress(h_y, @arr_y[I]);
PaxProgram1.Run;
ResValue := Double(PaxProgram1.ResultPtr^);
ShowMessage(FloatToStr(ResValue));
<font color="blue"><b>end</b></font>;
<font color="blue"><b>finally</b></font>
PaxProgram1.Free;
<font color="blue"><b>end</b></font>;
<font color="blue"><b>end</b></font>
<font color="blue"><b>else</b></font>
ShowMessage(<font color="Red">'Press the first button to create compiled script.'</font>);
<font color="blue"><b>end</b></font>;
<font color="blue"><b>procedure</b></font> TForm1.FormCreate(Sender: TObject);
<font color="blue"><b>begin</b></font>
h_x := 0; h_y := 0; h_norm := 0;
arr_x[1] := 4.2; arr_y[1] := -5.2;
arr_x[2] := -0.4; arr_y[2] := 3.2;
arr_x[3] := 2.0; arr_y[3] := 3;
<font color="blue"><b>end</b></font>;
<font color="blue"><b>end</b></font>.
</pre>
</blockquote>
<p>
<HR>
<font size = 1 color ="gray">
Copyright &copy; 2006-2009
VIRT Laboratory. All rights reserved.
</font>
</body>
</html>