Determining chapter number in different types of text
Try with this. Seems to work with given examples and some more:
<?php
$title[] = 'c005 - c009'; // c5-9
$title[] = 'c5.00 & c009'; // c5 & 9
$title[] = 'text c19 & c20 text'; //c19-20
$title[] = 'c19 & c20'; // c19-20
$title[] = 'text chapter 19 and chapter 25 text'; // c19 & 25
$title[] = 'text chapter 19 - chapter 23 and chapter 25 text'; // c19-23 & 25 (c19 for termless)
$title[] = 'text chapter 19 - chapter 23, chapter 25 text'; // c19-23 & 25 (c19 for termless)
$title[] = 'text chapter 23 text'; // c23
$title[] = 'text chapter 23, chapter 25-29 text'; // c23 & 25-29
$title[] = 'text chapters 23-26, 28, 29 + 30 + 32-39 text'; // c23-26 & c28-30 & c32-39
$title[] = 'text chapter 25.6 text'; // c25.6
$title[] = 'text chapters 23, 24, 25 text'; // c23-25
$title[] = 'text chapters 23+24+25 text'; // c23-25
$title[] = 'text chapter 23, 25 text'; // c23 & 25
$title[] = 'text chapter 23 & 24 & 25 text'; // c23-25
$title[] = 'text c25.5-30 text'; // c25.5-30
$title[] = 'text c99-c102 text'; // c99-102 (c99 for termless)
$title[] = 'text chapter 1 - 3 text'; // c1-3
$title[] = 'sometext 33 text chapter 1, 2 text 3'; // c1-2 or c33 if no terms
$title[] = 'text v2c5-10 text'; // c5-10 or c2 if no terms
$title[] = 'text cccc5-10 text'; // c5-10
$title[] = 'text chapters 23, 24, 25, 29, 31, 32 text'; // c23-25 & 29 & 31-32
$title[] = 'chapter 19 - chapter 23'; // c19-23 or c19 for termless
$title[] = 'chapter 12 part 2'; // c12
function get_chapter($text, $terms) {
$rterms = sprintf('(?:%s)', implode('|', $terms));
$and = '(?: [,&+]|\band\b )';
$isrange = "(?: \s*-\s* $rterms? \s*\d+ )";
$isdotnum = '(?:\.\d+)';
$the_regexp = "/(
$rterms \s* \d+ $isdotnum? $isrange?
( \s* $and \s* $rterms? \s* \d+ $isrange? )*
)/mix";
$result = array();
$result['orignal'] = $text;
if (preg_match($the_regexp, $text, $matches)) {
$result['found_match'] = $tmp = $matches[1];
$tmp = preg_replace("/$rterms\s*/i", '', $tmp);
$tmp = preg_replace('/\s*-\s*/', '-', $tmp);
$chapters = preg_split("/\s* $and \s*/ix", $tmp);
$chapters = array_map(function($x) {
return preg_replace('/\d\K\.0+/', '',
preg_replace('/(?|\b0+(\d)|-\K0+(\d))/', '\1', $x
));
}, $chapters);
$chapters = merge_chapters($chapters);
$result['converted'] = join_chapters($chapters);
}
else {
$result['found_match'] = '';
$result['converted'] = $text;
}
return $result;
}
function merge_chapters($chapters) {
$i = 0;
$begin = $end = -1;
$rtchapters = array();
foreach ($chapters as $chapter) {
// Fetch next chapter
$next = isset($chapters[$i+1]) ? $chapters[$i+1] : -1;
// If not set, set begin chapter
if ($begin == -1) {$begin = $chapter;}
if (preg_match('/-/', $chapter)) {
// It is a range, we reset begin/end and store the range
$begin = $end = -1;
array_push($rtchapters, $chapter);
}
else if ($chapter+1 == $next) {
// next is current + 1, update end
$end = $next;
}
else {
// store result (if no end, then store current chapter, else store the range
array_push($rtchapters, sprintf('%s', $end == -1 ? $chapter : "$begin-$end"));
$begin = $end = -1; // reset, since we stored results
}
$i++; // needed for $next
}
return $rtchapters;
}
function join_chapters($chapters) {
return 'c' . implode(' & ', $chapters) . "\n";
}
print "\nTERMS LEGEND:\n";
print "Case 1. = ['chapters', 'chapter', 'ch', 'c']\n";
print "Case 2. = []\n\n\n\n";
foreach ($title as $t) {
// If some patterns start by same letters, use longest first.
print "Original: $t\n";
print 'Case 1. = ';
$result = get_chapter($t, ['chapters', 'chapter', 'ch', 'c']);
print_r ($result);
print 'Case 2. = ';
$result = get_chapter($t, []);
print_r ($result);
print "--------------------------\n";
}
Output: See: https://ideone.com/Ebzr9R
Logic
I suggest the following approach that combines a regex and common string processing logic:
- use
preg_matchwith the appropriate regex to match the first occurrence of the whole chunk of text starting with the keyword from the$termsarray till the last number (+ optional section letter) related to the term - once the match is obtained, create an array that includes the input string, the match value, and the post-processed match
- post-processing can be done by removing spaces in between hyphenated numbers and rebuilding numeric ranges in case of numbers joined with
+,&or,chars. This requires a multi-step operation: 1) match the hyphen-separated substrings in the previous overall match and trim off unnecessary zeros and whitespace, 2) split the number chunks into separate items and pass them to a separate function that will generate the number ranges - the
buildNumChain($arr)function will create the number ranges and if a letter follows a number, will convert it to asection Xsuffix.
Solution
You may use
$strs = ['c0', 'c0-3', 'c0+3', 'c0 & 9', 'c0001, 2, 03', 'c01-03', 'c1.0 - 2.0', 'chapter 2A Hello', 'chapter 2AHello', 'chapter 10.4c', 'chapter 2B', 'episode 23.000 & 00024', 'episode 23 & 24', 'e23 & 24', 'text c25.6 text', '001 & 2 & 5 & 8-20 & 100 text chapter 25.6 text 98', 'hello 23 & 24', 'ep 1 - 2', 'chapter 1 - chapter 2', 'text chapter 25.6 text', 'text chapters 23, 24, 25 text','text chapter 23, 25 text', 'text chapter 23 & 24 & 25 text','text c25.5-30 text', 'text c99-c102 text', 'text chapter 1 - 3 text', '33 text chapter 1, 2 text 3','text chapters 23, 24, 25, 29, 31, 32 text', 'c19 & c20', 'chapter 25.6 & chapter 29', 'chapter 25+c26', 'chapter 25 + 26 + 27'];
$terms = ['episode', 'chapter', 'ch', 'ep', 'c', 'e', ''];
usort($terms, function($a, $b) {
return strlen($b) - strlen($a);
});
$chapter_main_rx = "\b(?|" . implode("|", array_map(function ($term) {
return strlen($term) > 0 ? "(" . substr($term, 0, 1) . ")(" . substr($term, 1) . "s?)": "()()" ;},
$terms)) . ")\s*";
$chapter_aux_rx = "\b(?:" . implode("|", array_map(function ($term) {
return strlen($term) > 0 ? substr($term, 0, 1) . "(?:" . substr($term, 1) . "s?)": "" ;},
$terms)) . ")\s*";
$reg = "~$chapter_main_rx((\d+(?:\.\d+)?(?:[A-Z]\b)?)(?:\s*(?:[,&+-]|and)\s*(?:$chapter_aux_rx)?(?4))*)~ui";
foreach ($strs as $s) {
if (preg_match($reg, $s, $m)) {
$p3 = preg_replace_callback(
"~(\d*(?:\.\d+)?)([A-Z]?)\s*-\s*(?:$chapter_aux_rx)?|(\d+(?:\.\d+)?(?:[A-Z]\b)?)(?:\s*(?:[,&+]|and)\s*(?:$chapter_aux_rx)?(?1))*~ui", function($x) use ($chapter_aux_rx) {
return (isset($x[3]) && strlen($x[3])) ? buildNumChain(preg_split("~\s*(?:[,&+]|and)\s*(?:$chapter_aux_rx)?~ui", $x[0]))
: ((isset($x[1]) && strlen($x[1])) ? ($x[1] + 0) : "") . ((isset($x[2]) && strlen($x[2])) ? ord(strtolower($x[2])) - 96 : "") . "-";
}, $m[3]);
print_r(["original" => $s, "found_match" => trim($m[0]), "converted" => $m[1] . $p3]);
echo "\n";
} else {
echo "No match for '$s'!\n";
}
}
function buildNumChain($arr) {
$ret = "";
$rngnum = "";
for ($i=0; $i < count($arr); $i++) {
$val = $arr[$i];
$part = "";
if (preg_match('~^(\d+(?:\.\d+)?)([A-Z]?)$~i', $val, $ms)) {
$val = $ms[1];
if (!empty($ms[2])) {
$part = ' part ' . (ord(strtolower($ms[2])) - 96);
}
}
$val = $val + 0;
if (($i < count($arr) - 1) && $val == ($arr[$i+1] + 0) - 1) {
if (empty($rngnum)) {
$ret .= ($i == 0 ? "" : " & ") . $val;
}
$rngnum = $val;
} else if (!empty($rngnum) || $i == count($arr)) {
$ret .= '-' . $val;
$rngnum = "";
} else {
$ret .= ($i == 0 ? "" : " & ") . $val . $part;
}
}
return $ret;
}
See the PHP demo.
Main points
- Match
corchapter/chapterswith numbers that follow them, capture justcand the numbers - After matches are found, process Group 2 that contains the number sequences
- All
<number>-c?<number>substrings should be stripped of whitespaces andcbefore/in between numbers and - All
,/&-separated numbers should be post-processed withbuildNumChainthat generates ranges out of consecutive numbers (whole numbers are assumed).
The main regex will look like if $terms = ['episode', 'chapter', 'ch', 'ep', 'c', 'e', '']:
'~(?|(e)(pisodes?)|(c)(hapters?)|(c)(hs?)|(e)(ps?)|(c)(s?)|(e)(s?)|()())\s*((\d+(?:\.\d+)?(?:[A-Z]\b)?)(?:\s*(?:[,&+-]|and)\s*(?:(?:e(?:pisodes?)|c(?:hapters?)|c(?:hs?)|e(?:ps?)|c(?:s?)|e(?:s?)|)\s*)?(?4))*)~ui'
See the regex demo.
Pattern details
(?|(e)(pisodes?)|(c)(hapters?)|(c)(hs?)|(e)(ps?)|(c)(s?)|(e)(s?)|()())- a branch reset group that captures the first letter of the search term and captures the rest of the term into an obligatory Group 2. If there is an empty term, the()()are added to make sure the branches in the group contain the same number of groups\s*- 0+ whitespaces((\d+(?:\.\d+)?(?:[A-Z]\b)?)(?:\s*(?:[,&+-]|and)\s*c?(?3))*)- Group 2:(\d+(?:\.\d+)?(?:[A-Z]\b)?)- Group 3: 1+ digits, followed with an optional sequence of., 1+ digits and then an optional ASCII letter that should be followed with a non-word char or end of string (note the case insensitive modifier will make[A-Z]also match lowercase ASCII letters)(?:\s*(?:[,&+-]|and)\s*(?:(?:e(?:pisodes?)|c(?:hapters?)|c(?:hs?)|e(?:ps?)|c(?:s?)|e(?:s?)|)\s*)?(?4))*- zero or more sequences of\s*(?:[,&+-]|and)\s*- a,,&,+,-orandenclosed with optional 0+ whitespaces(?:e(?:pisodes?)|c(?:hapters?)|c(?:hs?)|e(?:ps?)|c(?:s?)|e(?:s?)|)- any of the terms with added optional Plural endingss(?4)- Group 4 pattern recursed / repeated
When the regex matches, the Group 1 value is c, so it will be the first part of the result. Then,
"~(\d*(?:\.\d+)?)([A-Z]?)\s*-\s*(?:$chapter_aux_rx)?|(\d+(?:\.\d+)?(?:[A-Z]\b)?)(?:\s*(?:[,&+]|and)\s*(?:$chapter_aux_rx)?(?1))*~ui"
is used inside preg_replace_callback to remove whitespaces in between - (if any) and terms (if any) followed with 0+ whitespace chars, and if Group 1 matches, the match is split with
"~\s*(?:[,&+]|and)\s*(?:$chapter_aux_rx)?~ui"
regex (it matches &, ,, + or and in between optional 0+ whitespaces followed with 0+ whitespaces and then an optional string, terms followed with 0+ whitespaces) and the array is passed to the buildNumChain function that builds the resulting string.
I think that it is very complex to build something like this without throwing some false positives because some of the patterns might be contained in the title and in those cases, they will be detected by the code.
Anyway, I'll expose one solution that might be interesting to you, experiment with it when you have some time. I have not tested it deeply, so, if you find any problem with this implementation, let me know and I'll try to find a solution to it.
Looking at your patterns, all of them can be separated into two big groups:
- from one number to another number (G1)
- one or multiple numbers separated by commas, plus signs, or ampersands (G2)
So, if we can separate these two groups we can treat them differently. From the next titles, I'll try to get the chapter numbers in this way:
+-------------------------------------------+-------+------------------------+
| TITLE | GROUP | EXTRACT |
+-------------------------------------------+-------+------------------------+
| text chapter 25.6 text | G2 | 25.6 |
| text chapters 23, 24, 25 text | G2 | 23, 24, 25 |
| text chapters 23+24+25 text | G2 | 23, 24, 25 |
| text chapter 23, 25 text | G2 | 23, 25 |
| text chapter 23 & 24 & 25 text | G2 | 23, 24, 25 |
| text c25.5-30 text | G1 | 25.5 - 30 |
| text c99-c102 text | G1 | 99 - 102 |
| text chapter 99 - chapter 102 text | G1 | 99 - 102 |
| text chapter 1 - 3 text | G1 | 1 - 3 |
| 33 text chapter 1, 2 text 3 | G2 | 1, 2 |
| text v2c5-10 text | G1 | 5 - 10 |
| text chapters 23, 24, 25, 29, 31, 32 text | G2 | 23, 24, 25, 29, 31, 32 |
| text chapters 23 and 24 and 25 text | G2 | 23, 24, 25 |
| text chapters 23 and chapter 30 text | G2 | 23, 30 |
+-------------------------------------------+-------+------------------------+
To extract just the number of the chapters and differentiate them, one solution could be building a regular expression that captures two groups for the chapter ranges (G1) and one single group for the numbers separated by characters (G2). After the chapter numbers extraction, we can process the result to show the chapters correctly formatted.
Here is the code:
I've seen that you are still adding more cases in the comments that are not contained in the question. If you want to add a new case, just create a new matching pattern and add it to the final regexp. Just follow the rule of two matching groups for the ranges and a single matching group for the numbers separated by characters. Also, take into account that the most verbose patterns should be located before the lesser ones. For example
ccc N - ccc Nshould be located beforecc N - cc Nand this last one beforec N - c N.
$model = ['chapters?', 'chap', 'c']; // different type of chapter names
$c = '(?:' . implode('|', $model) . ')'; // non-capturing group for chapter names
$n = '\d+\.?\d*'; // chapter number
$s = '(?:[\&\+,]|and)'; // non-capturing group of valid separators
$e = '[ $]'; // end of a match (a space or an end of a line)
// Different patterns to match each case
$g1 = "$c *($n) *\- *$c *($n)$e"; // match chapter number - chapter number in all its variants (G1)
$g2 = "$c *($n) *\- *($n)$e"; // match chapter number - number in all its variants (G1)
$g3 = "$c *((?:(?:$n) *$s *)+(?:$n))$e"; // match chapter numbers separated by something in all its variants (G2)
$g4 = "((?:$c *$n *$s *)+$c *$n)$e"; // match chapter number and chater number ... and chapter numberin all its variants (G2)
$g5 = "$c *($n)$e"; // match chapter number in all its variants (G2)
// Build a big non-capturing group with all the patterns
$reg = "/(?:$g1|$g2|$g3|$g4|$g5)/";
// Function to process each title
function getChapters ($title) {
global $n, $reg;
// Store the matches in one flatten array
// arrays with three indexes correspond to G1
// arrays with two indexes correspond to G2
if (!preg_match($reg, $title, $matches)) return '';
$numbers = array_values(array_filter($matches));
// Show the formatted chapters for G1
if (count($numbers) == 3) return "c{$numbers[1]}-{$numbers[2]}";
// Show the formatted chapters for G2
if(!preg_match_all("/$n/", $numbers[1], $nmatches, PREG_PATTERN_ORDER)) return '';
$m = $nmatches[0];
$t = count($m);
$str = "c{$m[0]}";
foreach($m as $i => $mn) {
if ($i == 0) continue;
if ($mn == $m[$i - 1] + 1) {
if (substr($str, -1) != '-') $str .= '-';
if ($i == $t - 1 || $mn != $m[$i + 1] - 1) $str .= $mn;
} else {
if ($i < $t) $str .= ' & ';
$str .= $mn;
}
return $str;
}
}
You can check the code working on Ideone.