lib/bundleLocator.js
function (fullPath, relativePath, rule, parent) {
        var r,
            matches,
            defaultVersion = DEFAULT_VERSION,
            pkg;
        if (parent) {
            defaultVersion = parent.version;
        }

        relativePath = BundleLocator._toUnixPath(relativePath);

        for (r = 0; r < rule.length; r += 1) {
            matches = relativePath.match(rule[r].regex);
            if (matches) {
                try {
                    pkg = require(libpath.resolve(fullPath, 'package.json'));
                } catch (packageErr) {
                    // It's OK for a sub-bundle to not have a package.json.
                }
                return this._makeBundleSeed(fullPath, libpath.normalize(matches[1]), defaultVersion, pkg, rule[r].options);
            }
        }
    }
function (fullPath, relativePath, rule, parent) {
        var r,
            matches,
            defaultVersion = DEFAULT_VERSION,
            pkg;
        if (parent) {
            defaultVersion = parent.version;
        }

        relativePath = BundleLocator._toUnixPath(relativePath);

        for (r = 0; r < rule.length; r += 1) {
            matches = relativePath.match(rule[r].regex);
            if (matches) {
                try {
                    pkg = require(libpath.resolve(fullPath, 'package.json'));
                } catch (packageErr) {
                    // It's OK for a sub-bundle to not have a package.json.
                }
                return this._makeBundleSeed(fullPath, libpath.normalize(matches[1]), defaultVersion, pkg, rule[r].options);
            }
        }
    }
Processes the "_bundles" rule looking for child bundles.
Returns a "bundle seed" as described by _makeBundleSeed().

@private
@method _ruleBundles
@param {string} fullPath The full path to the file.
@param {string} relativePath The path relative to the parent bundle.
@param {object} rule The bundles rule.
@param {Bundle} parent The parent bundle.
@return {object|undefined} The processing options if the path is a child bundle.