How do I inspect a register as a list of lines in Vimscript?

Explanation

For advanced register debugging and macro tooling, plain getreg('a') is often not enough. It returns a flat string, which hides line structure and makes scripted transforms awkward. Using the extra arguments to getreg() lets you retrieve register data as a List of lines, which is much safer for analysis and programmatic edits.

How it works

:echo getreg('a', 1, 1)

• First argument 'a': target register
• Second argument 1: request the expression-friendly form
• Third argument 1: return a List instead of a single String

This makes multiline yanks, macros, and blockwise content easier to inspect without manual splitting.

Example

Assume register a contains three yanked lines. Running:

:echo getreg('a', 1, 1)

prints something like:

['first line', 'second line', 'third line']

From there, you can map or filter lines before writing back with setreg(), instead of applying brittle regex substitutions to one long string.

Tips

• Compare with :echo getreg('a') to see the difference in shape
• Pair with getregtype('a') when preserving char/line/block behavior
• Use this pattern when building reusable Vimscript commands that transform register content