src/Composer/Package/Archiver/HgExcludeFilter.php
public function parseHgIgnoreLine($line)
    {
        if (preg_match('#^syntax\s*:\s*(glob|regexp)$#', $line, $matches)) {
            if ($matches[1] === 'glob') {
                $this->patternMode = self::HG_IGNORE_GLOB;
            } else {
                $this->patternMode = self::HG_IGNORE_REGEX;
            }

            return null;
        }

        if ($this->patternMode == self::HG_IGNORE_GLOB) {
            return $this->patternFromGlob($line);
        }

        return $this->patternFromRegex($line);
    }
public function parseHgIgnoreLine($line)
    {
        if (preg_match('#^syntax\s*:\s*(glob|regexp)$#', $line, $matches)) {
            if ($matches[1] === 'glob') {
                $this->patternMode = self::HG_IGNORE_GLOB;
            } else {
                $this->patternMode = self::HG_IGNORE_REGEX;
            }

            return null;
        }

        if ($this->patternMode == self::HG_IGNORE_GLOB) {
            return $this->patternFromGlob($line);
        }

        return $this->patternFromRegex($line);
    }
Callback line parser which process hgignore lines

@param string $line A line from .hgignore

@return array|null An exclude pattern for filter()