How to create a range command that substitutes characters with grouping and back references?

Question

The use case is to copy citations from pdf files to markdown documents in vim. I'd create a dotted list of important copied text and then I'd like to replace the end of line hyphenation that appears in the copy text as such

- "bla bla bla bla bla bla bla bla bla bla, ex- cept bla bla bla bla bla bla bla bla 
bla bla bla bla bla bla bla bla bla bla bla. re- sult bla bla bla bla bla bla bla
bla bla bla bla bla bla bla bla bla bla bla bla."

When I use the following command on selected text :'<,'>s/\(\i\)- /\1/g it returns what I expect:

- “bla bla bla bla bla bla bla bla bla bla, except bla bla bla bla bla bla bla bla
bla bla bla bla bla bla bla bla bla bla bla. result bla bla bla bla bla bla bla
bla bla bla bla bla bla bla bla bla bla bla bla.”

To avoid memorizing and entering this pattern each time I need it, I tried to place this into a command called Hyphen in my .vimrc

command! -range=% Hyphen "s/\(\i\)- /\1/g"

Using :'<,'>Hyphen on selected text doesn't work. What am I missing?

Answer 1

You have to adjust your command:

1. remove quotes -- otherwise you command tries to execute a comment (" starts a comment in legacy vimscript)
2. specify range passed to s command, <line1> is a starting line of a command range, <line2> is the last line. Check :h <line1>.

command! -range=% Hyphen <line1>,<line2>s/\(\i\)- /\1/g

Answer 2

1. Vim uses " as comment leader. Since your RHS starts with a " the rest of the command is ignored and the whole thing does nothing.

   Fixed:

   :command! -range=% Hyphen s/\(\i\)- /\1/g
   

2. The RHS doesn't implicitly consume the line numbers so you must handle them explicitly.

   Fixed:

   :command! -range=% Hyphen execute '<line1>,<line2>s/\(\i\)- /\1/'