Crate fret_text_nav 

Text navigation helpers shared across Fret surfaces.

This crate centralizes v1 “word” and “line” semantics used by:

• core text widgets (TextInput, TextArea, SelectableText)
• ecosystem code editor surfaces

The active word-boundary mode (UnicodeWord vs Identifier) remains a policy input (TextBoundaryMode). This crate only provides deterministic algorithms for those modes.

Normative behavior is defined by:

• ADR 0179: Text Navigation and Word Boundaries (v1)
• ADR 0044: Text editing command vocabulary and UTF-8 byte indices (clamping rules)

Functions

clamp_to_char_boundary

clamp_to_grapheme_boundary

clamp_to_grapheme_boundary_down

clamp_to_grapheme_boundary_up

is_grapheme_boundary

move_word_left

move_word_right

next_char_boundary

next_grapheme_boundary

prev_char_boundary

prev_grapheme_boundary

select_line_range

select_word_range