# Acceptance Criteria for aki-stats (EARS Format)

## Event-Driven Requirements

*   **UC-1: Process Standard Input**
    *   When text is provided via standard input, the `aki-stats` utility shall calculate and display statistics for that text.

*   **UC-2: Process File Input**
    *   When one or more file paths are provided as arguments, the `aki-stats` utility shall read each file and display the combined statistics for all processed files.

## System Response Requirements

*   **UC-3: Calculate Line Count**
    *   When `aki-stats` processes text, the system shall calculate the total number of lines.

*   **UC-4: Calculate Word Count**
    *   When `aki-stats` processes text, the system shall calculate the total number of words.

*   **UC-5: Calculate Character Count**
    *   When `aki-stats` processes text, the system shall calculate the total number of characters.

*   **UC-6: Display Output**
    *   When statistics are calculated, the system shall display the line count, word count, and character count to standard output in a human-readable format.

## Ubiquitous Requirements (Non-Functional)

*   **NFR-1: Build Toolchain**
    *   The `aki-stats` utility shall always be buildable using the stable Rust toolchain.

*   **NFR-2: Cross-Platform**
    *   The `aki-stats` utility shall be buildable and runnable on macOS, Linux, and Windows environments.
