function parse_part($part)
{
//echo 'Parsing part: '.$part."\n";
// Let's start breaking down the reqs into logical units.
// XXX ###(, ###, ###, ...)
// Example: PHARM 129, 131, 220
// Means: You must take all three courses.
// XXX ### or ###
// Example: AFM 101 or 128
// Means: You must take one or the other.
$operators = array();
$state_machine = 0;
$depth = 0;
$brackets = array();
$grouped_operators = array();
$in_word = false;
$word_buffer = '';
$last_faculty = null;
$course_group = array();
$group_operator = 'and';
$last_operand = false;
$last_number = null;
$last_numerical_count = null;
$is_pairing = false;
$last_word_type = 0;
$numbers = array('one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine');
$part = ' ' . $part . ' ';
for ($ix = 0; $ix < strlen($part); ++$ix) {
$letter = $part[$ix];
if ($letter == '(') {
++$depth;
$brackets[] = $ix;
} else {
if ($letter == ')') {
--$depth;
$start_bracket = array_pop($brackets);
if (!$depth) {
$sub_operators = parse_reqs(substr($part, $start_bracket + 1, $ix - $start_bracket - 1));
$course_group = array_merge($course_group, $sub_operators);
}
} else {
if ($depth == 0) {
if (eregi('[a-z0-9]', $letter)) {
$word_buffer .= $letter;
$in_word = true;
} else {
if ($in_word) {
if ($letter == ',') {
//echo "found a comma...";
if ($last_operand) {
if (!empty($course_group)) {
$operators[] = array_merge(array($group_operator), $course_group);
$course_group = array();
}
$last_operand = false;
}
}
$new_word_type = 0;
if (strtolower($word_buffer) == 'or') {
if ($last_operand && $group_operator != strtolower($word_buffer)) {
// We've already added the last value for the previous operator, so let's
// group everything up to this point.
$course_group = array(array($group_operator, $course_group));
}
//echo "found an or operator\n";
$group_operator = 'or';
$last_operand = true;
} else {
if (strtolower($word_buffer) == 'and') {
//echo "found an and operator\n";
$group_operator = 'and';
$last_operand = true;
} else {
if (ereg('^[A-Z]+$', $word_buffer)) {
//echo 'found a faculty: '.$word_buffer."\n";
if ($is_pairing && $last_word_type == WORD_TYPE_FACULTY) {
$last_faculty = array_merge((array) $last_faculty, (array) $word_buffer);
$is_pairing = false;
} else {
$last_faculty = $word_buffer;
}
$new_word_type = WORD_TYPE_FACULTY;
} else {
if (ereg('^[0-9]{2,}[A-Z]?$', $word_buffer) && $letter != '%') {
foreach ((array) $last_faculty as $faculty) {
//echo 'found a course: '.$faculty.' '.$word_buffer."\n";
$course_group[] = new course($faculty, $word_buffer);
}
if ($is_pairing) {
$course2 = array_pop($course_group);
$course1 = array_pop($course_group);
$course_group[] = array('pair', $course1, $course2);
$is_pairing = false;
}
$new_word_type = WORD_TYPE_CNUM;
} else {
if (in_array(strtolower($word_buffer), $numbers)) {
$value = array_search(strtolower($word_buffer), $numbers) + 1;
$last_number = $value;
//echo 'found a number: '.$value."\n";
} else {
if ($last_number && strtolower($word_buffer) == 'of') {
$last_numerical_count = $last_number;
$last_number = null;
} else {
//echo 'found a word: '.$word_buffer."\n";
}
}
}
}
}
}
$last_word_type = $new_word_type;
if ($letter == '/') {
//echo "found a pairing operator\n";
$is_pairing = true;
}
$word_buffer = '';
$in_word = false;
}
}
}
}
}
}
if (!empty($course_group)) {
if ($last_numerical_count) {
$group_info = array($last_numerical_count);
} else {
$group_info = array($group_operator);
}
$operators[] = array_merge($group_info, $course_group);
}
//echo "done\n";
return $operators;
}
function parse_part($part)
{
//echo 'Parsing part: '.$part."\n";
// Let's start breaking down the reqs into logical units.
// XXX ###(, ###, ###, ...)
// Example: PHARM 129, 131, 220
// Means: You must take all three courses.
// XXX ### or ###
// Example: AFM 101 or 128
// Means: You must take one or the other.
$operators = array();
$state_machine = 0;
$depth = 0;
$brackets = array();
$grouped_operators = array();
$in_word = false;
$word_buffer = '';
$last_faculty = null;
$course_group = array();
//groups courses that shape same operator
$group_operator = 'and';
//operator applying to groups
$last_operand = false;
$last_number = null;
$last_numerical_count = null;
$is_pairing = false;
$last_word_type = 0;
$numbers = array('one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine');
$part = ' ' . $part . ' ';
for ($ix = 0; $ix < strlen($part); ++$ix) {
$letter = $part[$ix];
if ($letter == '(') {
++$depth;
$brackets[] = $ix;
//Add char position to end of $brackets
} else {
if ($letter == ')') {
--$depth;
$start_bracket = array_pop($brackets);
if (!$depth) {
//if we just closed bracket and not at depth 0
$sub_operators = parse_reqs(substr($part, $start_bracket + 1, $ix - $start_bracket - 1));
//parse inside the brackets
$course_group = array_merge($course_group, $sub_operators);
}
} else {
if ($depth == 0) {
if (eregi('[a-z0-9]', $letter)) {
//we run into non-cap letter or #
$word_buffer .= $letter;
$in_word = true;
} else {
if ($in_word) {
if ($letter == ',') {
//echo "found a comma...";
if ($last_operand) {
//last operand in a list
if (!empty($course_group)) {
//we already have courses in our list
$operators[] = array_merge(array($group_operator), $course_group);
// merge everything up until now
$course_group = array();
}
$last_operand = false;
//something must follow
}
}
//end of comma
$new_word_type = 0;
if (strtolower($word_buffer) == 'or') {
//if we ran into an or
if ($last_operand && $group_operator != strtolower($word_buffer)) {
//we had *and* operator before, this one is different
// We've already added the last value for the previous operator, so let's
// group everything up to this point.
$course_group = array(array($group_operator, $course_group));
}
//echo "found an or operator\n";
$group_operator = 'or';
$last_operand = true;
} else {
if (strtolower($word_buffer) == 'and') {
//echo "found an and operator\n";
$group_operator = 'and';
$last_operand = true;
} else {
if (ereg('^[A-Z]+$', $word_buffer)) {
//echo 'found a faculty: '.$word_buffer."\n";
if ($is_pairing && $last_word_type == WORD_TYPE_FACULTY) {
//when faculty only appears once, CS230/MATH330
$last_faculty = array_merge((array) $last_faculty, (array) $word_buffer);
//array of faculties? huh?
$is_pairing = false;
} else {
$last_faculty = $word_buffer;
}
$new_word_type = WORD_TYPE_FACULTY;
//we just addressed a faculty
} else {
if (ereg('^[0-9]{2,}[A-Z]?$', $word_buffer) && $letter != '%') {
//need to address what's a course
foreach ((array) $last_faculty as $faculty) {
//echo 'found a course: '.$faculty.' '.$word_buffer."\n";
$course_group[] = new course($faculty, $word_buffer);
//add course to group
}
if ($is_pairing) {
//if course pair
$course2 = array_pop($course_group);
$course1 = array_pop($course_group);
$course_group[] = array('pair', $course1, $course2);
$is_pairing = false;
}
$new_word_type = WORD_TYPE_CNUM;
} else {
if (in_array(strtolower($word_buffer), $numbers)) {
$value = array_search(strtolower($word_buffer), $numbers) + 1;
$last_number = $value;
//such as 3 of..
//echo 'found a number: '.$value."\n";
} else {
if ($last_number && strtolower($word_buffer) == 'of') {
$last_numerical_count = $last_number;
$last_number = null;
} else {
//echo 'found a word: '.$word_buffer."\n";
}
}
}
}
}
}
$last_word_type = $new_word_type;
if ($letter == '/') {
//echo "found a pairing operator\n";
$is_pairing = true;
}
$word_buffer = '';
$in_word = false;
}
}
//done that we're in a word (new word now?)
}
}
}
// done depth 0 actions
}
// done for loop
if (!empty($course_group)) {
if ($last_numerical_count) {
$group_info = array($last_numerical_count);
//ie they are connected by one of
} else {
$group_info = array($group_operator);
//they are connected by operator
}
$operators[] = array_merge($group_info, $course_group);
}
//echo "done\n";
return $operators;
}
