Refactored concordance method

Separated from concordance method the code block that finds the needle
positions and the code block that extract an excerpt of the text. Also included option to mark the needle to the returned text.

Author: Euak

src/Corpus/TextCorpus.php

@@ -77,71 +77,44 @@ public function getLexicalDiversity(string $lexicalDiversityClassName = Naive::c
      * @param int $contextLength The amount of space left and right of the found needle
      * @param bool $ignorecase
      * @param int $position. Available options: contain, begin, end, equal.
+     * @param bool $mark Option to mark the needle
      * @return array
      */
-    public function concordance(string $needle, int $contextLength = 20, bool $ignorecase = true, string $position = 'contain') : array
+    public function concordance(string $needle, int $contextLength = 20, bool $ignorecase = true, string $position = 'contain', bool $mark = false) : array
     {
         // temporary solution to handle unicode chars
-        $this->text = utf8_decode($this->text);
+        $text = utf8_decode($this->text);
+        $text = trim(preg_replace('/[\s\t\n\r\s]+/', ' ', $text));
         $needle = utf8_decode($needle);
-
-        $found = [];
-        $text = ' ' . trim(preg_replace('/[\s\t\n\r\s]+/', ' ', $this->text)) . ' ';
         $needleLength = strlen($needle);
-        $textLength = strlen($text);
-        $bufferLength = $needleLength + 2 * $contextLength;
-
-        // \p{L} or \p{Letter}: any kind of letter from any language.
-
-        $special_chars = "\/\-_\'";
-        $word_part = '\p{L}'.$special_chars;
-
-        switch ($position) {
-            case 'equal':
-                $pattern = "/[^$word_part]($needle)[^$word_part]/";
-                break;
-            case 'begin':
-                $pattern = "/[^$word_part]($needle)[$special_chars]?[\p{L}]*|^($needle)/";
-                break;
-            case 'end':
-                $pattern = "/[\p{L}]*[$special_chars]?[\p{L}]*($needle)[^$word_part]/";
-                break;
-            case 'contain':
-                $pattern = "/($needle)/";
-                break;
-            default:
-                $pattern = "/($needle)/";
-                break;
-        }
+        $found = [];
 
-        $case = $ignorecase ? 'i' : '';
-        preg_match_all($pattern.$case, $text, $matches, PREG_OFFSET_CAPTURE);
+        $positions = $this->concordancePositions($text, $needle, $contextLength, $ignorecase, $position);
 
         // Getting excerpts
-        foreach($matches[1] as $match) {
-
-            $needlePosition = $match[1];
-            $left = max($needlePosition - $contextLength, 0);
+        foreach($positions as $needlePosition) {
+            //marking the term
+            $text_marked = ($mark) ? Text::markString($text, $needlePosition, $needleLength, ['{{','}}']) : $text;
+            $needleLength_marked = ($mark) ? $needleLength+4 : $needleLength;
 
-            if($needleLength + $contextLength + $needlePosition > $textLength) {
-                $tmp = substr($text, $left);
-            } else {
-                $tmp = substr($text, $left, $bufferLength);
-            }
-            $found[] = utf8_encode($tmp);
+            $found[] = utf8_encode(Text::getExcerpt($text_marked, $needlePosition, $needleLength_marked, $contextLength));
         }
 
         return $found;
     }
 
-    public function occurrences(string $needle, int $contextLength = 20, bool $ignorecase = true, string $position = 'contain', bool $mark = false) : array
+    /**
+     * Return all positions of the needle in the text according to the position of the needle in a word.
+     * @param string $text
+     * @param int $needle
+     * @param int $contextLength The amount of space left and right of the found needle
+     * @param bool $ignorecase
+     * @param int $position. Available options: contain, begin, end, equal.
+     * @return array
+     */
+    public function concordancePositions(string $text, string $needle, int $contextLength = 20, bool $ignorecase = true, string $position = 'contain') : array
     {
-        // temporary solution to handle unicode chars
-        $text = utf8_decode($this->text);
-        $needle = utf8_decode($needle);
-
         $found = [];
-        $text = trim(preg_replace('/[\s\t\n\r\s]+/', ' ', $text));
         $needleLength = strlen($needle);
         $textLength = strlen($text);
         $bufferLength = $needleLength + 2 * $contextLength;
@@ -173,11 +146,7 @@ public function occurrences(string $needle, int $contextLength = 20, bool $ignor
         preg_match_all($pattern.$case, $text, $matches, PREG_OFFSET_CAPTURE);
         $positions = array_column($matches[1], 1);
 
-        $excerpts = array_map(function($needlePos) use ($needleLength, $text, $contextLength, $mark) {
-            return $this->extractExcerptTerm($needlePos, $needleLength, $text, $contextLength, $mark);
-        }, $positions);
-
-        return $excerpts;
+        return $positions;
     }
 
     /**