private void RestartButtonClicked(object sender, EventArgs e)
{
TokensLabel.Text = "";
TokensLabel.Hide();
LexemeTextBox.Text = "";
state = nameofState.START;
}
public void getToken(string s)
{
string mytoken = "";
bool res_flag = false;
int i = 0;
while (state != nameofState.END)
{
switch (state)
{
case nameofState.START:
if (isSpace(s[i]))
{
i++;
if (i == s.Length)
{
state = nameofState.END;
}
else
{
state = nameofState.START;
}
}
else if (isDigit(s[i]))
{
state = nameofState.NUMBER;
}
else if (isLetter(s[i]))
{
state = nameofState.IDENTIFIER;
}
else if (s[i] == ':')
{
state = nameofState.ASSIGNMENT;
}
else if (s[i] == '/' && s[i + 1] == '*')
{
state = nameofState.COMMENTSTATEMENT;
}
else if (isSymbol(s[i]))
{
switch (s[i])
{
case ';': TokensLabel.Text += tokenindicator + s[i] + "\n"; break;
case '"':
mytoken += s[i];
do
{
i++;
mytoken += s[i];
}while (s[i] != '"');
i++;
TokensLabel.Text += tokenindicator + mytoken + " ---- string \n";
mytoken = "";
break;
case '|':
case '&':
mytoken += s[i];
i++;
mytoken += s[i];
i++;
TokensLabel.Text += tokenindicator + mytoken + " ---- boolean_operator \n";
mytoken = "";
break;
case '+':
case '-':
case '*':
case '/':
case '–':
mytoken += s[i];
TokensLabel.Text += tokenindicator + mytoken + " ---- arithmetic operator \n";
mytoken = "";
break;
case '>':
case '<':
case '=':
mytoken += s[i];
TokensLabel.Text += tokenindicator + mytoken + " ---- condition operator \n";
mytoken = "";
break;
default: TokensLabel.Text += s[i] + " ---- symbol \n"; break;
}
i++;
if (i == s.Length)
{
state = nameofState.END;
}
else
{
state = nameofState.START;
}
}
else
{
state = nameofState.END;
}
break;
case nameofState.COMMENTSTATEMENT:
if (state == nameofState.COMMENTSTATEMENT)
{
mytoken += s[i];
i++;
while (s[i] != '/')
{
mytoken += s[i];
i++;
}
mytoken += s[i];
TokensLabel.Text += tokenindicator + mytoken + " ---- comment statement \n";
i++;
mytoken = "";
if (i == s.Length)
{
state = nameofState.END;
}
else
{
state = nameofState.START;
}
}
break;
case nameofState.NUMBER:
while (isDigit(s[i]) || s[i] == '.')
{
mytoken += s[i];
i++;
}
TokensLabel.Text += tokenindicator + mytoken + " ---- number \n";
mytoken = "";
if (i == s.Length)
{
state = nameofState.END;
}
else
{
state = nameofState.START;
}
break;
case nameofState.IDENTIFIER:
while (isLetter(s[i]) || isDigit(s[i]))
{
mytoken += s[i];
i++;
}
for (int count = 0; count < 13; count++)
{
if (RESERVERDWORD[count] == mytoken)
{
res_flag = true;
switch (RESERVERDWORD[count])
{
case "return":
mytoken += s[i];
while (s[i] != ';')
{
i++;
mytoken += s[i];
}
TokensLabel.Text += tokenindicator + mytoken + " ---- return statement \n";
break;
case "int":
case "float":
case "string":
TokensLabel.Text += tokenindicator + mytoken + " ---- reserved word(datatype) \n";
break;
case "if":
TokensLabel.Text += tokenindicator + mytoken + " ---- reserved word(if statement) \n";
break;
case "write":
mytoken += s[i];
TokensLabel.Text += tokenindicator + mytoken + " ---- write statement \n";
break;
case "read":
mytoken += s[i];
TokensLabel.Text += tokenindicator + mytoken + " ---- read statement \n";
break;
case "repeat":
TokensLabel.Text += tokenindicator + mytoken + " ---- reserved word(repeat statement) \n";
break;
default:
TokensLabel.Text += tokenindicator + mytoken + " ---- reserved word \n";
break;
}
}
;
}
if (s[i] == '(')
{
mytoken += s[i];
do
{
i++;
mytoken += s[i];
}while (s[i] != ')');
i++;
TokensLabel.Text += tokenindicator + mytoken + " ---- function call \n";
}
else if (res_flag == false)
{
TokensLabel.Text += tokenindicator + mytoken + " ---- identifier \n";
}
mytoken = "";
res_flag = false;
if (i == s.Length)
{
state = nameofState.END;
}
else
{
state = nameofState.START;
}
break;
case nameofState.ASSIGNMENT:
if (s[i] == ':')
{
TokensLabel.Text += tokenindicator + ":= ---- assignment operator \n";
i += 2;
state = nameofState.START;
}
else
{
if (i == s.Length)
{
state = nameofState.END;
}
else
{
state = nameofState.START;
}
}
break;
case nameofState.END:
break;
}
}
}
public void getNexttokenParser(string s, ref string CurrentToken, ref int startFromHere, ref nameofState state)
{
state = nameofState.START;
if (startFromHere == s.Length)
{
state = nameofState.END;
}
else
{
state = nameofState.START;
}
CurrentToken = "";
bool res_flag = false;
while (state != nameofState.END)
{
switch (state)
{
case nameofState.START:
if (isSpace(s[startFromHere]))
{
while (s[startFromHere] != '$')
{
startFromHere++;
if (startFromHere == s.Length)
{
state = nameofState.END;
break;
}
else
{
state = nameofState.START;
}
}
startFromHere++;
}
else if (isDigit(s[startFromHere]))
{
state = nameofState.NUMBER;
}
else if (isLetter(s[startFromHere]))
{
state = nameofState.IDENTIFIERorRESERVEDWORD;
}
else if (s[startFromHere] == ':')
{
state = nameofState.ASSIGNMENT;
}
else if (s[startFromHere] == '/' && s[startFromHere + 1] == '*')
{
state = nameofState.COMMENTSTATEMENT;
}
else if (isSymbol(s[startFromHere]))
{
switch (s[startFromHere])
{
case '(':
CurrentToken += s[startFromHere];
startFromHere++;
return;
case ')':
CurrentToken += s[startFromHere];
startFromHere++;
return;
case ';':
CurrentToken += s[startFromHere];
startFromHere++;
return;
case '"':
CurrentToken += s[startFromHere];
do
{
startFromHere++;
CurrentToken += s[startFromHere];
}while (s[startFromHere] != '"');
startFromHere++;
return;
case '|':
case '&':
CurrentToken += s[startFromHere];
startFromHere++;
CurrentToken += s[startFromHere];
startFromHere++;
return;
case '+':
case '-':
case '–':
CurrentToken += s[startFromHere];
startFromHere++;
state = nameofState.OPERATOR;
return;
case '*':
case '/':
CurrentToken += s[startFromHere];
startFromHere++;
state = nameofState.OPERATOR;
return;
case '>':
case '<':
case '=':
CurrentToken += s[startFromHere];
startFromHere++;
state = nameofState.OPERATOR;
return;
case ':':
CurrentToken += s[startFromHere];
startFromHere++;
return;
default:
break;
}
startFromHere++;
if (startFromHere == s.Length)
{
state = nameofState.END;
}
else
{
state = nameofState.START;
}
}
else
{
state = nameofState.END;
}
break;
case nameofState.COMMENTSTATEMENT:
if (state == nameofState.COMMENTSTATEMENT)
{
CurrentToken += s[startFromHere];
startFromHere++;
while (s[startFromHere] != '/')
{
CurrentToken += s[startFromHere];
startFromHere++;
}
CurrentToken += s[startFromHere];
startFromHere++;
return;
}
break;
case nameofState.NUMBER:
while (isDigit(s[startFromHere]) || s[startFromHere] == '.')
{
CurrentToken += s[startFromHere];
startFromHere++;
}
return;
case nameofState.IDENTIFIERorRESERVEDWORD:
while (isLetter(s[startFromHere]) || isDigit(s[startFromHere]))
{
CurrentToken += s[startFromHere];
startFromHere++;
}
for (int count = 0; count < 13; count++)
{
if (RESERVERDWORD[count] == CurrentToken)
{
state = nameofState.RESERVEDWORD;
res_flag = true;
switch (RESERVERDWORD[count])
{
case "return":
CurrentToken += s[startFromHere];
while (s[startFromHere] != ';')
{
startFromHere++;
CurrentToken += s[startFromHere];
}
startFromHere++;
return;
case "int":
case "float":
case "string":
TokensLabel.Text += CurrentToken + " ---- reserved word(datatype) \n";
return;
case "if":
return;
case "write":
return;
case "read":
return;
case "repeat":
return;
case "end":
return;
default:
return;
}
}
;
}
if (s[startFromHere] == '(')
{
CurrentToken += s[startFromHere];
do
{
startFromHere++;
CurrentToken += s[startFromHere];
}while (s[startFromHere] != ')');
startFromHere++;
return;
}
else if (res_flag == false)
{
state = nameofState.IDENTIFIER;
return;
}
CurrentToken = "";
res_flag = false;
if (startFromHere == s.Length)
{
state = nameofState.END;
}
else
{
state = nameofState.START;
}
break;
case nameofState.ASSIGNMENT:
if (s[startFromHere] == ':')
{
CurrentToken += s[startFromHere];
startFromHere++;
CurrentToken += s[startFromHere];
startFromHere++;
return;
}
else if (s[startFromHere] == '=')
{
CurrentToken += s[startFromHere];
startFromHere++;
return;
}
else
{
if (startFromHere == s.Length)
{
state = nameofState.END;
}
else
{
state = nameofState.START;
}
}
break;
case nameofState.END:
break;
}
}
}