regular lexer bkp

import java.util.ArrayList;
import java.util.regex.Matcher;
import java.util.regex.Pattern;



public class Lexer {
    private class Indexer {
        private int[] indexes;

        public Indexer() {
            indexes = new int[programText.size()];
            int index = 0;
            int sum = 0;
            for (String item : programText) {
                indexes[index] = sum;
                sum += item.length() + 1;
                index++;
            }
        }

        public int getMegaLinePosition(int position) {
            for (int index : indexes) {
                if (index >= position) return index;
            }
            return -1;
        }

        public int getMegaLineNumber(int position) {
            for (int i = 0; i < indexes.length; i++) {
                if (indexes[i] >= position) return i;
            }
            return -1;
        }

        public int getLineNumber(int position, String currentString) {
            for (int i = 0; i < indexes.length; i++) {
                if (indexes[i] >= (position + (megaString.length() - currentString.length()))) {
                    return i;
                }
            }
            return -1;
        }

        public int getLinePosition(int position, String currentString) {
            return (position + (megaString.length() - currentString.length())) - indexes[getLineNumber(position, currentString)];
        }
    }
    private ArrayList<String> programText;
    private String megaString;
    //private String keywords = "(^ifif|^dodo|^do)";
    private String ident = "([a-zA-Z]+)(\\2)";
    private String space = "[ \t\n]*";
    private String comment = "(^\\{|^\\(\\*)(\\*(?!\\))|[^}*]|[\n])*(\\}|\\*\\))";
    private int line = 1;
    private int col = 1;

    public Lexer() {
        megaString = new String("");
    }

    public void incrementPos(String str, int pos) {
        for (int i = 0; i < pos; i++) {
            if (str.charAt(i) == '\n') {
                line++;
                col = 1;
            } else {
                col++;
            }
        }
    }


    public void setProgramText(ArrayList<String> programText) {
        programText = new ArrayList<String>(programText);
    }

    public void analyze() {
        if (programText == null) {
            System.out.println("There is no text to analyze.");
            return;
        }

        for (String item : programText) {
            megaString = megaString.concat(item + "\n");
        }
        //System.out.println(megaString);

        String currentString = new String(megaString);
        Indexer indexer = new Indexer();

        //String pattern = "("+keywords+space+")|(^"+ident+space+")|("+comment+space+")";
        String keywordsPattern = "("+keywords+space+")";
        String identPattern = "(^"+ident+space+")";
        String commentPattern = "("+comment+space+")";
        Pattern kp = Pattern.compile(keywordsPattern);
        Pattern ip = Pattern.compile(identPattern);
        Pattern cp = Pattern.compile(commentPattern);
        //Pattern p = Pattern.compile(pattern);
        int errorFlag = 0;

        while (currentString.length() > 0) {
            Matcher km = kp.matcher(currentString);
            Matcher im = ip.matcher(currentString);
            Matcher cm = cp.matcher(currentString);
            //Matcher m = p.matcher(currentString);
            if (km.find()) {
                errorFlag = 0;
                if (km.group(1) != null) {
                    System.out.println("KEYWORD" + "(" + line + "," + col + ") : " + currentString.substring(0, km.end()));
                } else if (km.group(2) != null) {
                    System.out.println("km group 2 : " + currentString.substring(0, km.end()));
                } else if (km.group(3) != null) {
                    System.out.println("km group 3 : " + currentString.substring(0, km.end()));
                }
                incrementPos(currentString, km.end());
                currentString = currentString.substring(km.end(), currentString.length());
                continue;
            } else if (im.find()) {
                errorFlag = 0;
                if (im.group(1) != null) {
                    System.out.println("IDENT : " + "(" + line + "," + col + ") : " + currentString.substring(0, im.end()));
                } else if (im.group(2) != null) {
                    System.out.println("im group 2 : " + currentString.substring(0, im.end()));
                } else if (im.group(3) != null) {
                    System.out.println("im group 3 : " + currentString.substring(0, im.end()));
                }
                incrementPos(currentString, im.end());
                currentString = currentString.substring(im.end(), currentString.length());
                continue;
            } else if (cm.find()) {
                errorFlag = 0;
                if (cm.group(1) != null) {
                    System.out.println("COMMENT : " + "(" + line + "," + col + ") : " + currentString.substring(0, cm.end()));
                } else if (cm.group(2) != null) {
                    System.out.println("cm group 2 : " + currentString.substring(0, cm.end()));
                } else if (cm.group(3) != null) {
                    System.out.println("cm group 3 : " + currentString.substring(0, cm.end()));
                }
                incrementPos(currentString, cm.end());
                currentString = currentString.substring(cm.end(), currentString.length());
                continue;
            } else {
                if (errorFlag == 0) {
                    errorFlag = 1;
                    System.out.println("Error at line " + line + ", col " + col + ".");
                }
                incrementPos(currentString, 1);
            }
            //if (m.find()) {
                //if (m.group(1))

                //System.out.println(m.end() + ", cs: " + currentString);
            //    System.out.println(currentString.substring(0, m.end()));
            //    currentString = currentString.substring(m.end(), currentString.length());
            //}
        }
    }

}