package org.tartarus.snowball;
   import java.lang.reflect.InvocationTargetException;
   
   public class SnowballProgram {
       protected SnowballProgram()
       {
   	current = new StringBuffer();
   	setCurrent("");
      }
  
      /***
       * Set the current string.
       */
      public void setCurrent(String value)
      {
  	current.replace(0, current.length(), value);
  	cursor = 0;
  	limit = current.length();
  	limit_backward = 0;
  	bra = cursor;
  	ket = limit;
      }
  
      /***
       * Get the current string.
       */
      public String getCurrent()
      {
          String result = current.toString();
          // Make a new StringBuffer.  If we reuse the old one, and a user of
          // the library keeps a reference to the buffer returned (for example,
          // by converting it to a String in a way which doesn't force a copy),
          // the buffer size will not decrease, and we will risk wasting a large
          // amount of memory.
          // Thanks to Wolfram Esser for spotting this problem.
          current = new StringBuffer();
          return result;
      }
  
      // current string
      protected StringBuffer current;
  
      protected int cursor;
      protected int limit;
      protected int limit_backward;
      protected int bra;
      protected int ket;
  
      protected void copy_from(SnowballProgram other)
      {
  	current          = other.current;
  	cursor           = other.cursor;
  	limit            = other.limit;
  	limit_backward   = other.limit_backward;
  	bra              = other.bra;
  	ket              = other.ket;
      }
  
      protected boolean in_grouping(char [] s, int min, int max)
      {
  	if (cursor >= limit) return false;
  	char ch = current.charAt(cursor);
  	if (ch > max || ch < min) return false;
  	ch -= min;
  	if ((s[ch >> 3] & (0X1 << (ch & 0X7))) == 0) return false;
  	cursor++;
  	return true;
      }
  
      protected boolean in_grouping_b(char [] s, int min, int max)
      {
  	if (cursor <= limit_backward) return false;
  	char ch = current.charAt(cursor - 1);
  	if (ch > max || ch < min) return false;
  	ch -= min;
  	if ((s[ch >> 3] & (0X1 << (ch & 0X7))) == 0) return false;
  	cursor--;
  	return true;
      }
  
      protected boolean out_grouping(char [] s, int min, int max)
      {
  	if (cursor >= limit) return false;
  	char ch = current.charAt(cursor);
  	if (ch > max || ch < min) {
  	    cursor++;
  	    return true;
  	}
  	ch -= min;
  	if ((s[ch >> 3] & (0X1 << (ch & 0X7))) == 0) {
  	    cursor ++;
  	    return true;
  	}
  	return false;
      }
  
      protected boolean out_grouping_b(char [] s, int min, int max)
      {
 	if (cursor <= limit_backward) return false;
 	char ch = current.charAt(cursor - 1);
 	if (ch > max || ch < min) {
 	    cursor--;
 	    return true;
 	}
 	ch -= min;
 	if ((s[ch >> 3] & (0X1 << (ch & 0X7))) == 0) {
 	    cursor--;
 	    return true;
 	}
 	return false;
     }
 
     protected boolean in_range(int min, int max)
     {
 	if (cursor >= limit) return false;
 	char ch = current.charAt(cursor);
 	if (ch > max || ch < min) return false;
 	cursor++;
 	return true;
     }
 
     protected boolean in_range_b(int min, int max)
     {
 	if (cursor <= limit_backward) return false;
 	char ch = current.charAt(cursor - 1);
 	if (ch > max || ch < min) return false;
 	cursor--;
 	return true;
     }
 
     protected boolean out_range(int min, int max)
     {
 	if (cursor >= limit) return false;
 	char ch = current.charAt(cursor);
 	if (!(ch > max || ch < min)) return false;
 	cursor++;
 	return true;
     }
 
     protected boolean out_range_b(int min, int max)
     {
 	if (cursor <= limit_backward) return false;
 	char ch = current.charAt(cursor - 1);
 	if(!(ch > max || ch < min)) return false;
 	cursor--;
 	return true;
     }
 
     protected boolean eq_s(int s_size, String s)
     {
 	if (limit - cursor < s_size) return false;
 	int i;
 	for (i = 0; i != s_size; i++) {
 	    if (current.charAt(cursor + i) != s.charAt(i)) return false;
 	}
 	cursor += s_size;
 	return true;
     }
 
     protected boolean eq_s_b(int s_size, String s)
     {
 	if (cursor - limit_backward < s_size) return false;
 	int i;
 	for (i = 0; i != s_size; i++) {
 	    if (current.charAt(cursor - s_size + i) != s.charAt(i)) return false;
 	}
 	cursor -= s_size;
 	return true;
     }
 
     protected boolean eq_v(CharSequence s)
     {
 	return eq_s(s.length(), s.toString());
     }
 
     protected boolean eq_v_b(CharSequence s)
     {   return eq_s_b(s.length(), s.toString());
     }
 
     protected int find_among(Among v[], int v_size)
     {
 	int i = 0;
 	int j = v_size;
 
 	int c = cursor;
 	int l = limit;
 
 	int common_i = 0;
 	int common_j = 0;
 
 	boolean first_key_inspected = false;
 
 	while(true) {
 	    int k = i + ((j - i) >> 1);
 	    int diff = 0;
 	    int common = common_i < common_j ? common_i : common_j; // smaller
 	    Among w = v[k];
 	    int i2;
 	    for (i2 = common; i2 < w.s_size; i2++) {
 		if (c + common == l) {
 		    diff = -1;
 		    break;
 		}
 		diff = current.charAt(c + common) - w.s[i2];
 		if (diff != 0) break;
 		common++;
 	    }
 	    if (diff < 0) {
 		j = k;
 		common_j = common;
 	    } else {
 		i = k;
 		common_i = common;
 	    }
 	    if (j - i <= 1) {
 		if (i > 0) break; // v->s has been inspected
 		if (j == i) break; // only one item in v
 
 		// - but now we need to go round once more to get
 		// v->s inspected. This looks messy, but is actually
 		// the optimal approach.
 
 		if (first_key_inspected) break;
 		first_key_inspected = true;
 	    }
 	}
 	while(true) {
 	    Among w = v[i];
 	    if (common_i >= w.s_size) {
 		cursor = c + w.s_size;
 		if (w.method == null) return w.result;
 		boolean res;
 		try {
 		    Object resobj = w.method.invoke(w.methodobject,
 						    new Object[0]);
 		    res = resobj.toString().equals("true");
 		} catch (InvocationTargetException e) {
 		    res = false;
 		    // FIXME - debug message
 		} catch (IllegalAccessException e) {
 		    res = false;
 		    // FIXME - debug message
 		}
 		cursor = c + w.s_size;
 		if (res) return w.result;
 	    }
 	    i = w.substring_i;
 	    if (i < 0) return 0;
 	}
     }
 
     // find_among_b is for backwards processing. Same comments apply
     protected int find_among_b(Among v[], int v_size)
     {
 	int i = 0;
 	int j = v_size;
 
 	int c = cursor;
 	int lb = limit_backward;
 
 	int common_i = 0;
 	int common_j = 0;
 
 	boolean first_key_inspected = false;
 
 	while(true) {
 	    int k = i + ((j - i) >> 1);
 	    int diff = 0;
 	    int common = common_i < common_j ? common_i : common_j;
 	    Among w = v[k];
 	    int i2;
 	    for (i2 = w.s_size - 1 - common; i2 >= 0; i2--) {
 		if (c - common == lb) {
 		    diff = -1;
 		    break;
 		}
 		diff = current.charAt(c - 1 - common) - w.s[i2];
 		if (diff != 0) break;
 		common++;
 	    }
 	    if (diff < 0) {
 		j = k;
 		common_j = common;
 	    } else {
 		i = k;
 		common_i = common;
 	    }
 	    if (j - i <= 1) {
 		if (i > 0) break;
 		if (j == i) break;
 		if (first_key_inspected) break;
 		first_key_inspected = true;
 	    }
 	}
 	while(true) {
 	    Among w = v[i];
 	    if (common_i >= w.s_size) {
 		cursor = c - w.s_size;
 		if (w.method == null) return w.result;
 
 		boolean res;
 		try {
 		    Object resobj = w.method.invoke(w.methodobject,
 						    new Object[0]);
 		    res = resobj.toString().equals("true");
 		} catch (InvocationTargetException e) {
 		    res = false;
 		    // FIXME - debug message
 		} catch (IllegalAccessException e) {
 		    res = false;
 		    // FIXME - debug message
 		}
 		cursor = c - w.s_size;
 		if (res) return w.result;
 	    }
 	    i = w.substring_i;
 	    if (i < 0) return 0;
 	}
     }
 
     /* to replace chars between c_bra and c_ket in current by the
      * chars in s.
      */
     protected int replace_s(int c_bra, int c_ket, String s)
     {
 	int adjustment = s.length() - (c_ket - c_bra);
 	current.replace(c_bra, c_ket, s);
 	limit += adjustment;
 	if (cursor >= c_ket) cursor += adjustment;
 	else if (cursor > c_bra) cursor = c_bra;
 	return adjustment;
     }
 
     protected void slice_check()
     {
 	if (bra < 0 ||
 	    bra > ket ||
 	    ket > limit ||
 	    limit > current.length())   // this line could be removed
 	{
 	    System.err.println("faulty slice operation");
 	// FIXME: report error somehow.
 	/*
 	    fprintf(stderr, "faulty slice operation:\n");
 	    debug(z, -1, 0);
 	    exit(1);
 	    */
 	}
     }
 
     protected void slice_from(String s)
     {
 	slice_check();
 	replace_s(bra, ket, s);
     }
 
     protected void slice_from(CharSequence s)
     {
         slice_from(s.toString());
     }
 
     protected void slice_del()
     {
 	slice_from("");
     }
 
     protected void insert(int c_bra, int c_ket, String s)
     {
 	int adjustment = replace_s(c_bra, c_ket, s);
 	if (c_bra <= bra) bra += adjustment;
 	if (c_bra <= ket) ket += adjustment;
     }
 
     protected void insert(int c_bra, int c_ket, CharSequence s)
     {
 	insert(c_bra, c_ket, s.toString());
     }
 
     /* Copy the slice into the supplied StringBuffer */
     protected StringBuffer slice_to(StringBuffer s)
     {
 	slice_check();
 	int len = ket - bra;
 	s.replace(0, s.length(), current.substring(bra, ket));
 	return s;
     }
 
     /* Copy the slice into the supplied StringBuilder */
     protected StringBuilder slice_to(StringBuilder s)
     {
 	slice_check();
 	int len = ket - bra;
 	s.replace(0, s.length(), current.substring(bra, ket));
 	return s;
     }
 
     protected StringBuffer assign_to(StringBuffer s)
     {
 	s.replace(0, s.length(), current.substring(0, limit));
 	return s;
     }
 
     protected StringBuilder assign_to(StringBuilder s)
     {
 	s.replace(0, s.length(), current.substring(0, limit));
 	return s;
     }
 
 /*
 extern void debug(struct SN_env * z, int number, int line_count)
 {   int i;
     int limit = SIZE(z->p);
     //if (number >= 0) printf("%3d (line %4d): '", number, line_count);
     if (number >= 0) printf("%3d (line %4d): [%d]'", number, line_count,limit);
     for (i = 0; i <= limit; i++)
     {   if (z->lb == i) printf("{");
         if (z->bra == i) printf("[");
         if (z->c == i) printf("|");
         if (z->ket == i) printf("]");
         if (z->l == i) printf("}");
         if (i < limit)
         {   int ch = z->p[i];
             if (ch == 0) ch = '#';
             printf("%c", ch);
         }
     }
     printf("'\n");
 }
 */
 
 };