How to achieve selection different length of texts on different lines?

Question

assume I have following texts:

aaa-dd-e: "aaa",
bb-x: "bb",
c-9: "c"

I want to do selection like below:

aaa-dd-e: "aaa",
bb-x: "bb",
c-9: "c"

I tried using c-v to create a visual block, but after I create selection on the first column and I press "f:"( I meant to expand the selection to colon mark on every line like above), what I get is:

aaa-dd-e: "aaa",
bb-x: "bb",
c-9: "c"

the selection stops at the first colon and creates a rectangle.

Answer 1

Selection is generally a mean to an end, more so in Vim where selection is often not necessary in the first place.

Assuming you still want to put quotes around property names in your non-JSON file to turn it into proper JSON:

1. select the lines to modify, character-wise or line-wise, it doesn't matter,
2. :'<,'>norm I"^[f:i" ('<,'> is automatically inserted for you and ^[ is obtained with <C-v><Esc>).

If you have the beautiful surround plugin, step 2 becomes:

:'<,'>norm ^vt:S"

With a substitution, step 2 could become:

:'<,'>s/^\s*\([^:]*\):/"\1"

Answer 2

Vim only supports rectangular blockwise selections, with the exception of the jagged right border when you press $.

There are plugins (like vim multiple cursors) that can emulate multiple selections, but you should also be able to achieve your actual goal (which you unfortunately didn't mention) with pure Vim commands, for example :global and :substitute (if you can formulate a regular expression that matches the selection in each line), or by repeating macros (if there's a particular motion that covers the selection in each line).

Answer 3

Just to throw another hat into the ring, if you really want to use visual selection you can use the Tabular plugin to line up the colons, then make your visual selection.

If you take your original text:

aaa-dd-e: "aaa",
bb-x: "bb",
c-9: "c"

:Tab /:\zs will align everything after the colon, as below

aaa-dd-e:  "aaa",
bb-x:      "bb",
c-9:       "c"

And then you can make your visual block selection.

As others have said, though, visual selection is probably not necessary in this situation. Using norm or substitution can probably accomplish what you want without fussing with visual selections.

Answer 4

I've found a solution to this issue which is surprisingly simple! Start visual block mode from the bottom of the selection of the text you want to copy and select upwards! It will expand the block as you go up, whereas if you highlight downwards it appears to make the selection smaller.