Text width reference

This page is the task-oriented index to the text API. Use the generated Rust API reference for every signature, generic bound, trait implementation, and source link:

• Complete urushi API
• PrintableLines, PrintableText, and Grapheme
• TextSpan, StyledText, and StyledTextError
• TabPolicy and InvalidTabMarker

Printable text

Type	Public API
PrintableLines	new, lines
PrintableText	new, as_str, width, truncate, graphemes
Grapheme	new, as_str, width

These are borrowed transparent string views. Constructors validate the plain-text contract and panic when terminal controls violate it. truncate returns a grapheme-aligned prefix fitting the requested cell width.

Styled text

Type	Public API
TextSpan	new, text, style
StyledText	new, try_from_spans, as_str, spans, tab_policy, reset_tab_policy, get_tab_policy, width
StyledTextError	span and byte_offset identify a grapheme-splitting boundary

Styled spans are grapheme-aligned. A single grapheme cannot carry conflicting partial styles.

Tabs

TabPolicy::spaces(width) replaces each tab with that many spaces. TabPolicy::with_marker(width, marker) additionally selects the expansion marker and may return InvalidTabMarker. Accessors are width() and marker().

InvalidTabMarker distinguishes a control character, a zero-width grapheme, and a marker wider than the replacement width.

The default policy uses four-cell stops and blank expansion.

Layout guarantees

• Widths are terminal cells.
• Grapheme clusters remain atomic.
• CJK and emoji width participates in every View layout.
• Raw terminal controls are not accepted as printable text.
• Canvas never leaves half of a wide grapheme after clipping or overlap.