How do I execute a Vimscript expression as a macro without recording it?

Explanation

The @= command lets you type a Vimscript expression and execute the result as if it were a macro. Instead of recording keystrokes into a register, you dynamically build the keystroke sequence using any Vim expression. This is a powerful way to run one-off macros or computed keystroke sequences.

How it works

1. In normal mode, press @=
2. Vim opens the expression prompt (=)
3. Type any expression that evaluates to a string of keystrokes
4. Press <CR> to execute those keystrokes as a macro

The expression can use string concatenation, variables, function calls, or any valid Vimscript.

Example

To delete the next 3 words by computing the command dynamically:

@='3dw'

To insert a line of dashes matching the length of the current line:

@='o' . repeat('-', col('$')-1) . "\<Esc>"

This opens a new line, inserts dashes equal to the current line's length, then escapes.

Tips

• Use @@ afterward to repeat the last expression macro
• Unlike recorded macros, @= expressions can use variables and functions for dynamic behavior
• In insert mode, <C-r>= evaluates an expression and inserts the result as text (different from @= which executes as keystrokes)