cplmatch.c

BCAST Implementation for NS2

  return strcmp(m1->completion, m2->completion);
}

/*.......................................................................
 * Sort the array of matches in order of their suffixes.
 *
 * Input:
 *  cpl   WordCompletion *  The completion resource object.
 */
static void cpl_sort_suffixes(WordCompletion *cpl)
{
  qsort(cpl->result.matches, cpl->result.nmatch,
	sizeof(cpl->result.matches[0]), cpl_cmp_suffixes);
}

/*.......................................................................
 * This is a qsort() comparison function used to sort matches in order of
 * their suffixes.
 *
 * Input:
 *  v1, v2   void *  Pointers to the two matches to be compared.
 * Output:
 *  return    int    -1 -> v1 < v2.
 *                    0 -> v1 == v2
 *                    1 -> v1 > v2
 */
static int cpl_cmp_suffixes(const void *v1, const void *v2)
{
  const CplMatch *m1 = (const CplMatch *) v1;
  const CplMatch *m2 = (const CplMatch *) v2;
  return strcmp(m1->suffix, m2->suffix);
}

/*.......................................................................
 * Find the common prefix of all of the matching completion matches,
 * and record a pointer to it in cpl->result.suffix. Note that this has
 * the side effect of sorting the matches into suffix order.
 *
 * Input:
 *  cpl   WordCompletion *  The completion resource object.
 * Output:
 *  return           int    0 - OK.
 *                          1 - Error.
 */
static int cpl_common_suffix(WordCompletion *cpl)
{
  CplMatches *result;       /* The result container */
  const char *first, *last; /* The first and last matching suffixes */
  int length;               /* The length of the common suffix */
/*
 * Get the container of the array of matching files.
 */
  result = &cpl->result;
/*
 * No matching completions?
 */
  if(result->nmatch < 1)
    return 0;
/*
 * Sort th matches into suffix order.
 */
  cpl_sort_suffixes(cpl);
/*
 * Given that the array of matches is sorted, the first and last
 * suffixes are those that differ most in their prefixes, so the common
 * prefix of these strings is the longest common prefix of all of the
 * suffixes.
 */
  first = result->matches[0].suffix;
  last = result->matches[result->nmatch - 1].suffix;
/*
 * Find the point at which the first and last matching strings
 * first difffer.
 */
  while(*first && *first == *last) {
    first++;
    last++;
  };
/*
 * How long is the common suffix?
 */
  length = first - result->matches[0].suffix;
/*
 * Allocate memory to record the common suffix.
 */
  result->suffix = _sg_alloc_string(cpl->sg, length);
  if(!result->suffix) {
    strcpy(cpl->errmsg,
	   "Insufficient memory to record common completion suffix.");
    return 1;
  };
/*
 * Record the common suffix.
 */
  strncpy(result->suffix, result->matches[0].suffix, length);
  result->suffix[length] = '\0'; 
  return 0;
}

/*.......................................................................
 * Discard the contents of the array of possible completion matches.
 *
 * Input:
 *  cpl   WordCompletion *  The word-completion resource object.
 */
static void cpl_clear_completions(WordCompletion *cpl)
{
/*
 * Discard all of the strings.
 */
  _clr_StringGroup(cpl->sg);
/*
 * Record the fact that the array is now empty.
 */
  cpl->result.nmatch = 0;
  cpl->result.suffix = NULL;
  cpl->result.cont_suffix = "";
/*
 * Also clear the error message.
 */
  cpl->errmsg[0] = '\0';
  return;
}

/*.......................................................................
 * Given an input line and the point at which it completion is to be
 * attempted, return an array of possible completions.
 *
 * Input:
 *  cpl    WordCompletion *  The completion resource object.
 *  line             char *  The current input line.
 *  word_end          int    The index of the character in line[] which
 *                           follows the end of the token that is being
 *                           completed.
 *  data             void *  Anonymous 'data' to be passed to match_fn().
 *  match_fn   CplMatchFn *  The function that will identify the prefix
 *                           to be completed from the input line, and
 *                           record completion matches.
 * Output:
 *  return     CplMatches *  The container of the array of possible
 *                           completions. The returned pointer refers
 *                           to a container owned by the parent WordCompletion
 *                           object, and its contents thus potentially
 *                           change on every call to cpl_matches().
 *                           On error, NULL is returned, and a description
 *                           of the error can be acquired by calling
 *                           cpl_last_error(cpl).
 */
CplMatches *cpl_complete_word(WordCompletion *cpl, const char *line,
				int word_end, void *data, 
				CplMatchFn *match_fn)
{
  int line_len;   /* The total length of the input line */
/*
 * How long is the input line?
 */
  line_len = strlen(line);
/*
 * Check the arguments.
 */
  if(!cpl || !line || !match_fn || word_end < 0 || word_end > line_len) {
    if(cpl)
      strcpy(cpl->errmsg, "cpl_complete_word: Invalid arguments.");
    return NULL;
  };
/*
 * Clear the return container.
 */
  cpl_clear_completions(cpl);
/*
 * Have the matching function record possible completion matches in
 * cpl->result.matches.
 */
  if(match_fn(cpl, data, line, word_end)) {
    if(cpl->errmsg[0] == '\0')
      strcpy(cpl->errmsg, "Error completing word.");
    return NULL;
  };
/*
 * Record a copy of the common initial part of all of the prefixes
 * in cpl->result.common.
 */
  if(cpl_common_suffix(cpl))
    return NULL;
/*
 * Sort the matches into lexicographic order.
 */
  cpl_sort_matches(cpl);
/*
 * Discard any duplicate matches.
 */
  cpl_zap_duplicates(cpl);
/*
 * If there is more than one match, discard the continuation suffix.
 */
  if(cpl->result.nmatch > 1)
    cpl->result.cont_suffix = "";
/*
 * Return the array of matches.
 */
  return &cpl->result;
}

/*.......................................................................
 * Print out an array of matching completions.
 *
 * Input:
 *  result  CplMatches *   The container of the sorted array of
 *                         completions.
 *  fp            FILE *   The output stream to write to.
 *  term_width     int     The width of the terminal.
 * Output:
 *  return         int     0 - OK.
 *                         1 - Error.
 */
int cpl_list_completions(CplMatches *result, FILE *fp, int term_width)
{
  int maxlen;    /* The length of the longest matching string */
  int width;     /* The width of a column */
  int ncol;      /* The number of columns to list */
  int nrow;      /* The number of rows needed to list all of the matches */
  int row,col;   /* The row and column being written to */
  int i;
  int newline, onewline; /* Flags if the prev/curr string ends on '\n' */
/*
 * Check the arguments.
 */
  if(!result || !fp) {
    fprintf(stderr, "cpl_list_completions: NULL argument(s).\n");
    return 1;
  };
/*
 * Not enough space to list anything?
 */
  if(term_width < 1)
    return 0;
/*
 * Work out the maximum length of the matching strings.
 */
  maxlen = 0;
  for(i=0; i<result->nmatch; i++) {
    CplMatch *match = result->matches + i;
    int len = strlen(match->completion) +
              strlen(match->type_suffix);
    if(len > maxlen)
      maxlen = len;
  };
/*
 * Nothing to list?
 */
  if(maxlen == 0)
    return 0;
/*
 * Split the available terminal width into columns of maxlen + 2 characters.
 */
  width = maxlen + 2;
  ncol = term_width / width;
/*
 * If the column width is greater than the terminal width, the matches will
 * just have to overlap onto the next line.
 */
  if(ncol < 1)
    ncol = 1;
/*
 * How many rows will be needed?
 */
  nrow = (result->nmatch + ncol - 1) / ncol;
/*
 * Print the matches out in ncol columns, sorted in row order within each
 * column.
 */
  onewline = 1;
  newline = 1;
  for(row=0; row < nrow; row++) {
    for(col=0; col < ncol; col++) {
      int m = col*nrow + row;
      onewline = newline;
      newline = 0;
      if(m < result->nmatch) {
	CplMatch *match = result->matches + m;
	/* Compute if the result string ends on '\n' */
	do {
	    int len = strlen(match->type_suffix);
	    if (len) {
		if (match->type_suffix[len-1] == '\n')
		    newline = 1;
		break;
	    }
	    len = strlen(match->completion);
	    if (len) {
		if (match->type_suffix[len-1] == '\n')
		    newline = 1;
		break;
	    }
	} while (0);
	if(fprintf(fp, "%s%-*s%s", match->completion,
		   (int) (((!onewline) && ncol > 1) ? maxlen - strlen(match->completion):0),
		   match->type_suffix, newline ? "" : col<ncol-1 ? "  " : "\r\n") < 0)
	  return 1;
      } else {
	if(!onewline && fprintf(fp, "\r\n") < 0)
	  return 1;
	newline = 1;
	break;
      };
    };
  };
  return 0;
}

/*.......................................................................
 * Return a description of the string-completion error that occurred.
 *
 * Input:
 *  cpl   WordCompletion *  The string-completion resource object.
 * Output:
 *  return    const char *  The description of the last error.