import java.io.FileInputStream;
import java.io.InputStreamReader;

public class Lexer {
        InputStreamReader reader;
        int buffsize;
        char token;
        int cs; /* state number */
        char[] data;
        public int p = 0, /* start of input */
            pe,  /* end of input */
            eof,
            ts, /* token start */
            te, /* token end */
            act /* used for scanner backtracking */;

%%{
  machine simple_lexer;
    a  = 'a';
  main := |*
    a => {token='a'; fbreak;};
    # EOF => {token='e'; fbreak;};
    any;
  *|;
}%%
%% write data;

    public static void main(String[] args) throws Exception{
      InputStreamReader reader = new InputStreamReader(new FileInputStream(args[0]), "UTF-8");
      Lexer l = new Lexer(reader);
      long start = System.currentTimeMillis();
          while ( true ) {
            int tok = l.next();
            if ( tok == -1 ) {
              System.out.println("parser: EOF");
              break;
            }
            else if ( tok == -2 ) {
              System.out.println("parser: ERR");
              break;
            }
          }
      long stop = System.currentTimeMillis();
      System.out.println(stop-start);
    }

    public Lexer(InputStreamReader reader){
        this.reader = reader;
        buffsize = 4096;
        p=pe=0;
        data=new char[buffsize];
        %% write init;
    }

    public int next() throws Exception {
      token = 'n';
      while(true) {
        if ( p==pe ) {
          int size = reader.read(data, 0, buffsize);
          if (size==-1){
            return -1;
          }
          pe = size;
          if (size < buffsize){
            eof=pe=size;
          }
          p=0;
        }

        %% write exec;
        if ( token =='e' ) {
          return -1;
        }
        if ( token =='a' ) {
          return 0;
        }
        return 4;
    }
  }

}