Senin, 22 April 2013

kompiler dengan bahasa pascal


program scanner; { judul program}
uses Wincrt;
var
prg_sumber,f_hasil:text;
karakter:Char;
kata,Nm_token:string;
procedure bacafile; { prosedur membaca file sumber }
begin
read(prg_sumber,karakter);
end;
procedure hasil; {prosedur utk menulis hasil setiap token}
begin
append(f_hasil); {menambah hasil scan ke file hasil}
writeln(f_hasil, kata : 15, ' : ', Nm_token);
writeln(kata : 15, ' : ', Nm_token); {mencetak hasil scan ke layar}
end;
function cekkeyword(s:string):string; {fungsi mengecek keyword atau bukan}
var
x : byte;
panjang : integer;
ftext : text;
data : string;                                                                      
begin
panjang:= length(s); {konversi kata ke huruf kecil}
for x:=1 to panjang do
begin
if s[x] > upcase (s[x]) then
s[x] := s[x]
else
s[x]:= chr(ord(s[x])+32);
end;
assign(ftext,'keyword.txt');
reset(ftext);
while not eof(ftext) do {mencocokkan dgn tabel keyword}
begin
readln(ftext,data);
if s=data then Nm_token:='Identifier / Keyword';
end;
close(ftext);
end;
procedure periksa; {prosedur memeriksa setiap karakter file sumber}
begin
while not eof(prg_sumber) do {kerjakan sampai akhir file}
begin
bacafile;
if karakter = '{' then {mengabaikan/membuang komentar}
begin
repeat
begin
bacafile;
end;
until karakter = '}';
kata:=' ';
end;
if karakter = chr(39) then {mengecek tanda petik (')}
begin
repeat
begin
kata := kata + karakter;
bacafile;
end;
until karakter = chr(39) ;
kata := kata + karakter;
Nm_token := 'Konstanta';
hasil;
kata :=' ';
end;
if (karakter in['A'..'Z','a'..'z','_']) then {mengecek karakter/kata}
begin
repeat
begin
kata := kata + karakter;
bacafile;
end;
until (not(karakter in['A'..'Z','a'..'z','_']));
Nm_token:='Identifier / Variabel';
cekkeyword(kata);
hasil;
kata :=' ';
end;
if (karakter in['0'..'9']) then {mengecek angka}
begin
repeat
begin
kata := kata + karakter;
bacafile;
end;
until (not(karakter in['0'..'9']));
Nm_token := 'Konstanta / Integer';
hasil;
kata :=' ';
end;
if (karakter in['+','-','*','/',' ','^']) then
begin
repeat
begin
kata := kata+karakter;
bacafile;
end;
until (not(karakter in['+','-','*','/',' ','^']));
Nm_token :='Operator';
hasil;
kata:=' ';
end;
if (karakter in['(',')','[',']','^',':',';',',','.']) then
begin
kata:=karakter;
Nm_token :='Delimiter';
hasil;
kata:=' ';
end;
end;
end;
begin {=program utama=}
clrscr;
assign(prg_sumber,'coba.txt'); {menetapkan file sumber}
reset(prg_sumber); {membaca file sumber}
assign(f_hasil,'hasil.txt'); {menetapkan file hasil}
rewrite(f_hasil); {menghapus isi file hasil}
periksa; {menjalankan prosedur scan}
close(prg_sumber); {menutup file}
close(f_hasil);
readln;
end.

outputnya :