characterwise

Characterwise refers to operations, selections, or processing that apply to text one character at a time, rather than by lines, words, or rectangular blocks. It is a common concept in text editors and programming tasks, enabling fine-grained edits and transformations.

In text editors, characterwise is a key granularity for selections and operations. For example, in Vim, there are three visual selection modes: characterwise, linewise, and blockwise. A characterwise selection covers text from the first to the last character, potentially spanning multiple lines. Operators such as d (delete), y (yank), c (change), or > (indent) act on a range defined by a following motion; if the motion is character-based, the result is a characterwise operation, whereas line-based motions yield linewise, and blockwise motions yield a rectangular selection. In Vim, pressing v enters characterwise Visual mode, while Ctrl-V enters Block mode and V enters Line mode.

In programming and text processing, characterwise processing means iterating over or transforming strings at the level of individual characters. This is opposed to wordwise processing, which relies on word boundaries, or grapheme-aware processing, which treats user-perceived characters as units. Characterwise handling is sensitive to encoding, especially for Unicode text where a single user-perceived character may consist of multiple code points. The term is used across editors and languages to describe per-character operations and should be distinguished from per-word or per-line approaches.