/**
 * Returns true when specifier is a local-path source.
 *
 * A specifier is local-path iff it begins with './', '../', or '/'.
 * Mirrors the private isLocalExtension function at src/build/build.ts:254.
 */
export declare function isLocalPath(specifier: string): boolean;
/**
 * Extract the bare package name from a registry specifier or mount value.
 *
 * Strips the trailing version qualifier — the part after the last '@' that is
 * NOT in the leading scope position. The leading '@' on scoped packages
 * (`@scope/...`) is preserved.
 *
 * Examples:
 *   "@rcrsr/rill-ext-datetime"       -> "@rcrsr/rill-ext-datetime"
 *   "@rcrsr/rill-ext-datetime@0.19.0"-> "@rcrsr/rill-ext-datetime"
 *   "@rcrsr/rill-ext-datetime@^0.19.0"-> "@rcrsr/rill-ext-datetime"
 *   "my-pkg@^1.0.0"                  -> "my-pkg"
 *   "my-pkg"                         -> "my-pkg"
 */
export declare function extractPackageName(specifier: string): string;
/**
 * Returns true when the specifier looks like a local single-file path based on
 * its suffix alone (no filesystem access). Safe to call during argument parsing
 * before the path is known to exist on disk.
 *
 * Use this predicate when reading values from rill-config.json or when the
 * file may not yet exist (e.g. during install argument validation).
 */
export declare function looksLikeLocalFilePath(specifier: string): boolean;
/**
 * Returns true when specifier is a local path that points at an existing
 * single source file (ts/js/mjs/cjs/tsx/jsx). Performs a stat to distinguish
 * a file named e.g. `foo.ts` from a directory with the same name.
 *
 * Requires the path to exist on disk — only call this after confirming the
 * specifier resolves to a real filesystem entry.
 */
export declare function isLocalFilePath(specifier: string): boolean;
/**
 * Derive mount path from a package specifier or local path.
 *
 * Algorithm (FR-EXT-2/3/4):
 * - If asOverride supplied: return asOverride.
 * - If specifier is empty: throw Error.
 * - If specifier is a local path (./  ../  /): return basename of path.
 * - Else if specifier matches /^@[^/]+\/rill-ext-(.+)$/: return capture group.
 * - Else if specifier matches /^rill-ext-(.+)$/: return capture group.
 * - Else if scoped (@scope/name): return name (last segment).
 * - Else: return specifier as-is.
 */
export declare function deriveMount(specifier: string, asOverride?: string): string;