regexps(string, expression, varargin)

function matches = regexps(string, expression, varargin)
%REGEXPS Match regular expression.
%   MATCHES = REGEXPS(STRING,EXPRESSION) returns a structure array of the search
%   results with the elements: MATCHES.match which is the string that represents
%   the match; and MATCHES.tokens which is a cell array of strings that reprent
%   the tokens for that match.
%
%   By default, REGEXPS returns all matches and is case sensitive
%   Available options are:
%
%      'ignorecase'   - Ignore the case of characters when matching EXPRESSION
%                       to STRING.
%      'once'         - Return only the first occurrence of EXPRESSION in
%                       STRING.
%
%   Example
%      str = 'six sides of a hexagon';
%      pat = 's(\w*)s';
%      matches = regexps(str, pat)
%         returns
%            matches.match = 'sides'
%            matches.tokens = {'ide'}
%
%   See also REGEXP, REGEXPREP

%	J Breslau
%   Copyright (c) 1995-2002 The MathWorks, Inc.


    try
        [first last tokens] = regexp(string, expression, varargin{:});
    catch
        % use regexprep to make the error look like it came from here.
        errStr = regexprep(lasterr, '^.*?\n([^\n]*)$', '$1', 'tokenize');
        errStr = regexprep(errStr, 'regexp\w*', 'regexps', 'preservecase', 'once');
        error(errStr);
    end

    if (iscell(first))
        if (~iscell(string))
            string = {string};
        end
        dims = size(first);
        for row = 1:dims(1)
            for col = 1:dims(2)
                matches{row, col} = parseResults(first{row, col}, last{row, col}, tokens{row, col}, string{row});
            end
        end
    else
        matches = parseResults(first, last, tokens, string);
    end

function matches = parseResults(first, last, tokens, string)
    matches = [];

    for i = 1:length(first)
        matches(i).match = string(first(i):last(i));
        matches(i).tokens = {};
        for j = 1:size(tokens{i},1)
            if tokens{i}(j,1)
                matches(i).tokens{j} = string(tokens{i}(j,1):tokens{i}(j,2));
            end
        end
    end