Module delta_display 

Unified delta display system for streaming content.

This module provides centralized logic for displaying partial vs. complete content consistently across all parsers. It handles visual distinction, real-time streaming display, and automatic transition from delta to complete.

DeltaRenderer Trait

The DeltaRenderer trait defines a consistent interface for rendering streaming deltas across all parsers. Implementations must ensure:

• First chunk shows prefix with accumulated content ending with carriage return
• Subsequent chunks update in-place (clear line, rewrite with prefix, carriage return)
• Final output adds newline when streaming completes

In-Place Updates

The terminal escape sequences used for in-place updates:

• \x1b[2K - Clears the entire line (not just to end like \x1b[0K)
• \r - Returns cursor to the beginning of the line

This ensures that previous content is completely erased before displaying the updated content, preventing visual artifacts.

Multi-Line In-Place Update Pattern

The renderer uses a multi-line pattern with cursor positioning for in-place updates. This is the industry standard for streaming CLIs (used by Rich, Ink, Bubble Tea).

[ccs-glm] Hello\n\x1b[1A             <- First chunk: prefix + content + newline + cursor up
\x1b[2K\r[ccs-glm] Hello World\n\x1b[1A  <- Second chunk: clear, rewrite, newline, cursor up
[ccs-glm] Hello World\n\x1b[1B\n       <- Final: move cursor down + newline

This pattern ensures:

• Newline forces immediate terminal output buffer flush
• Cursor positioning provides reliable in-place updates
• Production-quality rendering used by major CLI libraries

Terminal Mode Detection

The renderer automatically detects terminal capability and adjusts output:

• Full mode: Uses cursor positioning for in-place updates (TTY with capable terminal)
• Basic mode: Uses colors but no cursor positioning (e.g., TERM=dumb)
• None mode: No ANSI sequences (pipes, redirects, CI environments)

Prefix Display Strategy

The prefix (e.g., [ccs-glm]) is displayed on every delta update by default. This provides clear visual feedback about which agent is currently streaming.

Prefix Debouncing

For scenarios where prefix repetition creates visual noise (e.g., character-by-character streaming), the [PrefixDebouncer] can be used to control prefix display frequency. It supports both delta-count-based and time-based strategies:

• Count-based: Show prefix every N deltas (default: every delta)
• Time-based: Show prefix after M milliseconds since last prefix

The debouncer is opt-in; the default behavior shows prefix on every delta.

Structs

DeltaDisplayFormatter

Delta display formatter

TextDeltaRenderer

Default implementation of DeltaRenderer for text content.

Constants

CLEAR_LINE

ANSI escape sequence for clearing the entire line.

Traits

DeltaRenderer

Renderer for streaming delta content.

Functions

sanitize_for_display

Sanitize content for single-line display during streaming.