/** True when some of `content` is hidden from the model by redaction. */
export declare function hasHiddenValues(content: string): boolean;
/**
 * Returns an error message when writing `next` over `original` would put
 * redaction markers where real values were, or null when the write is safe.
 * `original` is undefined for a new file, which has nothing to lose.
 */
export declare function redactionLossError(original: string | undefined, next: string, fileName: string): string | null;
/** Hint appended when an edit's old_text contains the marker and fails to match. */
export declare function redactedOldTextHint(oldText: string): string;