public class StreamProgLexer {
public static void main (String [] args) {
try {
int ch, ch2, ch3, ch4, ch5, ch6, ch7, ch8, ch9, ch10, ch11;
CharEingabeStrom cs;
cs = new StringLeser (args[0]);
cs = new UmlautSzFilter (cs);
//cs = new GrossBuchstabenFilter (cs);
CharEingabeStrom while_stream;
CharEingabeStrom begin_stream;
CharEingabeStrom end_stream;
CharEingabeStrom if_stream;
CharEingabeStrom then_stream;
CharEingabeStrom else_stream;
CharEingabeStrom do_stream;
CharEingabeStrom empty_character_stream;
CharEingabeStrom newline_stream;
CharEingabeStrom tab_stream;
while_stream = new StringLeserLoop ("WHILE");
begin_stream = new StringLeserLoop ("BEGIN");
end_stream = new StringLeserLoop ("END");
if_stream = new StringLeserLoop ("IF");
then_stream = new StringLeserLoop ("THEN");
else_stream = new StringLeserLoop ("ELSE");
do_stream = new StringLeserLoop ("DO");
empty_character_stream = new StringLeserLoop (" ");
newline_stream = new StringLeserLoop ("\n");
tab_stream = new StringLeserLoop ("\t");
while ((ch = cs.read()) != -1) {
if (((ch2 = while_stream.read()) != ch) && (ch2 != -1)) {
while (ch2 != -1)
ch2 = while_stream.read();
}
else if (ch2 == -1)
System.out.println ("WHILE found");
if (((ch3 = begin_stream.read()) != ch) && (ch3 != -1)) {
while (ch3 != -1)
ch3 = begin_stream.read();
}
else if (ch3 == -1)
System.out.println ("BEGIN found");
if (((ch4 = end_stream.read()) != ch) && (ch4 != -1)) {
while (ch4 != -1)
ch4 = end_stream.read();
}
else if (ch4 == -1)
System.out.println ("END found");
if (((ch5 = if_stream.read()) != ch) && (ch5 != -1)) {
while (ch5 != -1)
ch5 = if_stream.read();
}
else if (ch5 == -1)
System.out.println ("IF found");
}
}
catch (ArrayIndexOutOfBoundsException e) {
System.out.println ("usage: java StreamProg arg1");
}
}
interface CharEingabeStrom {
int read();
}
public static class StringLeser implements CharEingabeStrom {
private String quelle;
private int index;
public StringLeser (String quelle) {
this.quelle = quelle;
}
@Override
public int read () {
if ((index == quelle.length()))
return -1;
return quelle.charAt (index++);
}
}
public static class StringLeserLoop implements CharEingabeStrom {
private String quelle;
private int index;
public StringLeserLoop (String quelle) {
this.quelle = quelle;
}
@Override
public int read () {
if ((index == quelle.length())) {
index = 0;
return -1;
}
return quelle.charAt (index++);
}
}
public static class GrossBuchstabenFilter implements CharEingabeStrom {
private CharEingabeStrom quelle;
public GrossBuchstabenFilter (CharEingabeStrom quelle) {
this.quelle = quelle;
}
@Override
public int read () {
int zeichen = quelle.read();
if (zeichen == -1)
return -1;
return Character.toUpperCase ((char) zeichen);
}
}
public static class UmlautSzFilter implements CharEingabeStrom {
private CharEingabeStrom quelle;
private int puffer = -1;
public UmlautSzFilter (CharEingabeStrom quelle) {
this.quelle = quelle;
}
@Override
public int read () {
if (puffer != -1) {
int zeichen = puffer;
puffer = -1;
return zeichen;
}
else {
int zeichen = quelle.read ();
if (zeichen == -1)
return -1;
switch ((char) zeichen) {
case '\u00C4':
puffer = 'e';
return 'A';
case '\u00D6':
puffer = 'e';
return 'O';
case '\u00DC':
puffer = 'e';
return 'U';
case '\u00E4':
puffer = 'e';
return 'a';
case '\u00F6':
puffer = 'e';
return 'o';
case '\u00FC':
puffer = 'e';
return 'u';
case '\u00DF':
puffer = 's';
return 's';
default:
return zeichen;
}
}
}
}
}
