unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics,
  Controls, Forms, Dialogs, StdCtrls, ComCtrls;

type
  TForm1 = class(TForm)
    RichEdit1: TRichEdit;
    Button1: TButton;
    OpenDialog1: TOpenDialog;
    Button2: TButton;
    procedure RichEdit1KeyUp(Sender: TObject; var Key: Word;
      Shift: TShiftState);
    procedure HighLight;
    function CheckList(InString: string): boolean;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

function TForm1.CheckList(InString: string): boolean;
const TheList: array[1..13] of string = ('begin', 'or', 'end','end.',
'end;', 'then', 'var', 'for', 'do', 'if', 'to', 'string', 'while');
var X: integer;
begin
  Result := false;
  X := 1;
  InString := StringReplace(InString, ' ', '',[rfReplaceAll]);
  InString := StringReplace(InString, #$A, '',[rfReplaceAll]);
  InString := StringReplace(InString, #$D, '',[rfReplaceAll]);
  while X < High(TheList) + 1 do
  if TheList[X] = lowercase(InString) then
  begin
    Result := true;
    X := High(TheList) + 1;
  end
  else inc(X);
end;

procedure TForm1.RichEdit1KeyUp(Sender: TObject; var Key: Word;
  Shift: TShiftState);
var WEnd, WStart, BCount: integer;
  Mark: string;
begin
  if (ssCtrl in Shift) and (Key = ord('V')) then Button2Click(Self);
  if (Key = VK_Return) or (Key = VK_Back) or (Key = VK_Space) then
  begin
    if RichEdit1.SelStart > 1 then
    begin
      WStart := 0;
      WEnd := RichEdit1.SelStart;
      BCount := WEnd - 1;
      while BCount <> 0 do
      begin
        Mark := copy(RichEdit1.Text, BCount, 1);
        if (Mark = ' ') or (Mark = #$A) then
        begin
          WStart := BCount;
          BCount := 1;
        end;
        dec(BCount);
      end;
      RichEdit1.SelStart := WEnd - (WEnd - WStart);
      RichEdit1.SelLength := WEnd - WStart;
      if CheckList(RichEdit1.SelText) then
        RichEdit1.SelAttributes.Style := [fsBold]
      else RichEdit1.SelAttributes.Style := [];
      RichEdit1.SelStart := WEnd;
      RichEdit1.SelAttributes.Style := [];
    end;
  end;
end;

function SearchFor(WorkSpace, Search: string; Start: integer): integer;
var Temp: string;
begin
  Temp := copy(WorkSpace, Start, length(WorkSpace));
  Result := pos(Search, Temp);
end;

procedure TForm1.HighLight;
var WStart, WEnd, WEnd2: integer;
  WorkSpace, SWord: string;
begin
  WStart  :=  1;
  WEnd  :=  1;
  with  RichEdit1 do
  begin
    WorkSpace  :=  Text + ' ' + #$D#$A;
    while WEnd > 0 do
    begin
      WEnd := SearchFor(WorkSpace, ' ', WStart);
      WEnd2 := SearchFor(WorkSpace, #$A, WStart);
      if WEnd2 < WEnd then WEnd := WEnd2;
      SWord := copy(WorkSpace, WStart, WEnd - 1);
      if (SWord <> ' ') and (SWord <>'') then
        if CheckList(SWord) then
        begin
          SelStart  := WStart - 1;
          SelLength := length(SWord);
          SelAttributes.Style := [fsBOLD];
          SelStart := WStart + length(SWord) + 1;
          SelAttributes.Style := [];
        end;
      WStart := WStart + WEnd;
    end;
    SelStart := length(Text);
    SetFocus;
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  if OpenDialog1.Execute then
  begin
    RichEdit1.Lines.LoadFromFile(OpenDialog1.FileName);
    HighLight;
  end;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  RichEdit1.PasteFromClipboard;
  HighLight;
end;

end.