Vim operators and motions: a grammar

Vim commands are a verb plus a noun, like d2w, so a few operators and motions give hundreds of edits. An operator such as d, c, y or gU does nothing alone. It puts Vim in operator pending mode and waits for a motion, then acts on the text between the cursor and where that motion would land.

Transcript

A line of code sits in a buffer while operator and motion tiles snap together into commands like d2w and di(, and the cursor and highlighted range show exactly which text each sentence deletes or changes.

echo 'let total = price * (qty + tax)' > t.txt
vim -Nu NONE -n -es -c 'normal d2w' -c wq t.txt
cat t.txt
# = price * (qty + tax)

Same line, other sentences (cursor starts on l):

wcwsum<Esc>  let sum = price * (qty + tax)
f(di(        let total = price * ()
fqd$         let total = price * (
3wgUiw       let total = PRICE * (qty + tax)

The animation chains d2w, f(di( and FpgUiw on one line instead (Fp finds p backward), ending at = PRICE * ().

Why it scales#

:help operator lists 16 operators; ~ is one only when 'tildeop' is set, so 15 by default. Each accepts any motion (w, $, f(, /qty<CR>) and any text object (iw, i(, a"). Learn one new motion and every operator gains it for free: multiplication, not memorization. Counts multiply too, so 2d3w deletes six words.

The motion decides the shape#

j is linewise, so dj deletes two whole lines. t is exclusive and f is inclusive: on our line dtp leaves price, dfp leaves rice. Doubling an operator means "this line": dd, yy, gUgU.

The boundary#

• cw is a documented special case: on a word it acts like ce and keeps the trailing blanks. On one two, cwX gives X two while dwiX gives Xtwo.
• A bare dw on the last word of a line stops at the line end. A count crosses it: on one two / three four, d2w from two leaves one four.
• Text objects are not motions. They work only after an operator or in Visual mode: typing iw alone enters Insert mode and types a w.

Rule of thumb#

When you reach for Visual mode to select and then delete, say the edit as a sentence instead. "Delete inside parens" is di(, and it works from anywhere inside them. Vim's grammar fits on an index card, which is why people spend a decade on the vocabulary.