private void Tokenize_Click(object sender, EventArgs e)
{
//taking user input from rich textbox
String userInput = Input.Text;
//List of keywords which will be used to seperate keywords from variables
List <String> keywordList = new List <String>();
keywordList.Add("int");
keywordList.Add("float");
keywordList.Add("while");
keywordList.Add("main");
keywordList.Add("if");
keywordList.Add("else");
keywordList.Add("new");
//row is an index counter for symbol table
int row = 1;
//count is a variable to incremenet variable id in tokens
int count = 1;
//line_num is a counter for lines in user input
int line_num = 0;
//SymbolTable is a 2D array that has the following structure
//[Index][Variable Name][type][value][line#]
//rows are incremented with each variable information entry
String[,] SymbolTable = new String[20, 6];
List <String> varListinSymbolTable = new List <String>();
//Input Buffering
ArrayList finalArray = new ArrayList();
ArrayList finalArrayc = new ArrayList();
ArrayList tempArray = new ArrayList();
char[] charinput = userInput.ToCharArray();
//Regular Expression for Variables
Regex variable_Reg = new Regex(@"^[A-Za-z|_][A-Za-z|0-9]*$");
//Regular Expression for Constants
Regex constants_Reg = new Regex(@"^[0-9]+([.][0-9]+)?([e]([+|-])?[0-9]+)?$");
//Regular Expression for Operators
Regex operators_Reg = new Regex(@"^[-*+/><&&||=]$");
//Regular Expression for Special_Characters
Regex Special_Reg = new Regex(@"^[.,'\[\]{}();:?]$");
for (int itr = 0; itr < charinput.Length; itr++)
{
Match Match_Variable = variable_Reg.Match(charinput[itr] + "");
Match Match_Constant = constants_Reg.Match(charinput[itr] + "");
Match Match_Operator = operators_Reg.Match(charinput[itr] + "");
Match Match_Special = Special_Reg.Match(charinput[itr] + "");
if (Match_Variable.Success || Match_Constant.Success || Match_Operator.Success || Match_Special.Success || charinput[itr].Equals(' '))
{
tempArray.Add(charinput[itr]);
}
if (charinput[itr].Equals('\n'))
{
if (tempArray.Count != 0)
{
int j = 0;
String fin = "";
for (; j < tempArray.Count; j++)
{
fin += tempArray[j];
}
finalArray.Add(fin);
tempArray.Clear();
}
}
}
if (tempArray.Count != 0)
{
int j = 0;
String fin = "";
for (; j < tempArray.Count; j++)
{
fin += tempArray[j];
}
finalArray.Add(fin);
tempArray.Clear();
}
// Final Array SO far correct
Output.Clear();
ST.Clear();
//looping on all lines in user input
for (int i = 0; i < finalArray.Count; i++)
{
String line = finalArray[i].ToString();
//tfTokens.AppendText(line + "\n");
char[] lineChar = line.ToCharArray();
line_num++;
//taking current line and splitting it into lexemes by space
for (int itr = 0; itr < lineChar.Length; itr++)
{
Match Match_Variable = variable_Reg.Match(lineChar[itr] + "");
Match Match_Constant = constants_Reg.Match(lineChar[itr] + "");
Match Match_Operator = operators_Reg.Match(lineChar[itr] + "");
Match Match_Special = Special_Reg.Match(lineChar[itr] + "");
if (Match_Variable.Success || Match_Constant.Success)
{
tempArray.Add(lineChar[itr]);
}
if (lineChar[itr].Equals(' '))
{
if (tempArray.Count != 0)
{
int j = 0;
String fin = "";
for (; j < tempArray.Count; j++)
{
fin += tempArray[j];
}
finalArrayc.Add(fin);
tempArray.Clear();
}
}
if (Match_Operator.Success || Match_Special.Success)
{
if (tempArray.Count != 0)
{
int j = 0;
String fin = "";
for (; j < tempArray.Count; j++)
{
fin += tempArray[j];
}
finalArrayc.Add(fin);
tempArray.Clear();
}
finalArrayc.Add(lineChar[itr]);
}
}
if (tempArray.Count != 0)
{
String fina = "";
for (int k = 0; k < tempArray.Count; k++)
{
fina += tempArray[k];
}
finalArrayc.Add(fina);
tempArray.Clear();
}
// we have asplitted line here
for (int x = 0; x < finalArrayc.Count; x++)
{
Match operators = operators_Reg.Match(finalArrayc[x].ToString());
Match variables = variable_Reg.Match(finalArrayc[x].ToString());
Match digits = constants_Reg.Match(finalArrayc[x].ToString());
Match punctuations = Special_Reg.Match(finalArrayc[x].ToString());
if (operators.Success)
{
// if a current lexeme is an operator then make a token e.g. < op, = >
Output.AppendText("< op, " + finalArrayc[x].ToString() + "> ");
}
else if (digits.Success)
{
// if a current lexeme is a digit then make a token e.g. < digit, 12.33 >
Output.AppendText("< digit, " + finalArrayc[x].ToString() + "> ");
}
else if (punctuations.Success)
{
// if a current lexeme is a punctuation then make a token e.g. < punc, ; >
Output.AppendText("< punc, " + finalArrayc[x].ToString() + "> ");
}
else if (variables.Success)
{
// if a current lexeme is a variable and not a keyword
if (!keywordList.Contains(finalArrayc[x].ToString())) // if it is not a keyword
{
// check what is the category of varaible, handling only two cases here
//Category1- Variable initialization of type digit e.g. int count = 10 ;
//Category2- Variable initialization of type String e.g. String var = ' Hello ' ;
Regex reg1 = new Regex(@"^(int|float|double)\s([A-Za-z|_][A-Za-z|0-9]{0,10})\s(=)\s([0-9]+([.][0-9]+)?([e][+|-]?[0-9]+)?)\s(;)$"); // line of type int alpha = 2 ;
Match category1 = reg1.Match(line);
Regex reg2 = new Regex(@"^(String|char)\s([A-Za-z|_][A-Za-z|0-9]{0,10})\s(=)\s[']\s([A-Za-z|_][A-Za-z|0-9]{0,30})\s[']\s(;)$"); // line of type String alpha = ' Hello ' ;
Match category2 = reg2.Match(line);
//if it is a category 1 then add a row in symbol table containing the information related to that variable
if (category1.Success)
{
SymbolTable[row, 1] = row.ToString(); //index
SymbolTable[row, 2] = finalArrayc[x].ToString(); //variable name
SymbolTable[row, 3] = finalArrayc[x - 1].ToString(); //type
SymbolTable[row, 4] = finalArrayc[x + 2].ToString(); //value
SymbolTable[row, 5] = line_num.ToString(); // line number
Output.AppendText("<var" + count + ", " + row + "> ");
ST.AppendText(SymbolTable[row, 1].ToString() + " \t ");
ST.AppendText(SymbolTable[row, 2].ToString() + " \t ");
ST.AppendText(SymbolTable[row, 3].ToString() + " \t ");
ST.AppendText(SymbolTable[row, 4].ToString() + " \t ");
ST.AppendText(SymbolTable[row, 5].ToString() + " \n ");
row++;
count++;
}
//if it is a category 2 then add a row in symbol table containing the information related to that variable
else if (category2.Success)
{
// if a line such as String var = ' Hello ' ; comes and the loop moves to index of array containing Hello ,
//then this if condition prevents addition of Hello in symbol Table because it is not a variable it is just a string
if (!(finalArrayc[x - 1].ToString().Equals("'") && finalArrayc[x + 1].ToString().Equals("'")))
{
SymbolTable[row, 1] = row.ToString(); // index
SymbolTable[row, 2] = finalArrayc[x].ToString(); //varname
SymbolTable[row, 3] = finalArrayc[x - 1].ToString(); //type
SymbolTable[row, 4] = finalArrayc[x + 3].ToString(); //value
SymbolTable[row, 5] = line_num.ToString(); // line number
Output.AppendText("<var" + count + ", " + row + "> ");
ST.AppendText(SymbolTable[row, 1].ToString() + " \t ");
ST.AppendText(SymbolTable[row, 2].ToString() + " \t ");
ST.AppendText(SymbolTable[row, 3].ToString() + " \t ");
ST.AppendText(SymbolTable[row, 4].ToString() + " \t ");
ST.AppendText(SymbolTable[row, 5].ToString() + " \n ");
row++;
count++;
}
else
{
Output.AppendText("<String" + count + ", " + finalArrayc[x].ToString() + "> ");
}
}
else
{
// if any other category line comes in we check if we have initializes that varaible before,
// if we have initiazed it before then we put the index of that variable in symbol table, in its token
String ind = "Default";
String ty = "Default";
String val = "Default";
String lin = "Default";
for (int r = 1; r <= SymbolTable.GetLength(0); r++)
{
//search in the symbol table if variable entry already exists
if (SymbolTable[r, 2].Equals(finalArrayc[x].ToString()))
{
ind = SymbolTable[r, 1];
ty = SymbolTable[r, 3];
val = SymbolTable[r, 4];
lin = SymbolTable[r, 5];
Output.AppendText("<var" + ind + ", " + ind + "> ");
break;
}
}
}
}
// if a current lexeme is not a variable but a keyword then make a token such as: <keyword, int>
else
{
Output.AppendText("<keyword, " + finalArrayc[x].ToString() + "> ");
}
}
}
Output.AppendText("\n");
finalArrayc.Clear();
}
#region Display Symbol Table
for (int j = 0; j < Symboltable.Count; j++)
{
for (int z = 0; z < Symboltable[j].Count; z++)
{
ST.AppendText(Symboltable[j][z] + "\t");
}
ST.AppendText("\n");
}
#endregion
}