Mixedwidth

Mixedwidth refers to text that contains characters with different display widths when rendered, typically in contexts where some characters occupy more horizontal space than others. In typography and digital rendering, glyphs can be monospaced (each character uses the same width) or proportional (width varies by character). In East Asian typography, many characters are designed as fullwidth or wide, occupying two standard character cells, while Latin letters and digits are usually halfwidth or narrow, occupying one cell. When such characters appear together, the text is said to be mixedwidth.

In computing, mixedwidth affects how text is laid out, measured, and aligned. Display width determines how many columns a string occupies in a terminal, editor, or data grid. Unicode defines the East Asian Width property to classify characters as fullwidth, wide, halfwidth, narrow, neutral, or ambiguous. Implementations often use width calculation functions (for example, wcwidth and wcswidth in POSIX environments) to determine how many columns a string should occupy. Ambiguous width characters can be treated as either one or two columns depending on locale, and combining characters can join with base characters without advancing the cursor, complicating measurement.

Practical implications include alignment and truncation in terminal displays, fixed-column data formats, and text rendering in editors and IDEs. Mixedwidth text can complicate search, indexing, and cursor movement, requiring careful handling of character widths and Unicode properties. Tools and libraries that render or process text—such as terminals, programming editors, and typesetting systems—often implement specialized logic to compute display width accurately, taking into account wide and narrow characters, emoji sequences, and combining marks. See also East Asian width, wcwidth, monospaced and proportional fonts, and Unicode text rendering.