Bsrgvty

If I have a list using itemize, I want to automatically end each item with a semicolon (for all but the last item) or a period (for the last item).

For example:

beginitemize
 item One
 item Two
 item Three
enditemize

Should display as

• One;


• Two;


• Three.

Is there any way to make that happen? I looked around but didn't really find anything. The closest I could find was this, but that seems to be a fancy, custom list rather than a vanilla itemize.

I'm not sure whether it is a good idea to do this, maybe you should use a different environment for that. The following patches item inside every itemize environment to add a semicolon after the first, and the enditemize macro is changed to add a dot. You can no longer nest itemize environments with this simple approach. All in all I think this creates more problems than it solves...

documentclass[]article

usepackageetoolbox
AtBeginEnvironmentitemize
 %
 defitemizepunctuationdefitemizepunctuationifhmodeunskipfi;%
 pretocmditemitemizepunctuation%
 pretocmdenditemizeifhmodeunskipfi.%
 

newenvironmentpunctitemize
 %
 itemize
 defitemizepunctuationdefitemizepunctuationifhmodeunskipfi;%
 pretocmditemitemizepunctuation%
 pretocmdenditemizeifhmodeunskipfi.%
 
 %
 enditemize
 

begindocument
beginitemize
 item One
 item Two
 item Three
enditemize

beginpunctitemize
 item One
 item Two
 item Three
endpunctitemize
enddocument

EDIT: added the environment approach, nesting is still not supported.

You can use xparse, absorbing the whole contents and splitting it at item; then add a semicolon (and the removed item) between items.

The processing is complicated by the fact that a blank line between items would introduce a spurious paragraph before the semicolon or the final period, so we need to remove blanks and par tokens at the end of each item.

Thus the sequence obtained by splitting at item is mapped to “purify” it.

I added enumitem for maximum flexibility.

documentclassarticle
usepackagexparse
usepackageenumitem

ExplSyntaxOn

NewDocumentEnvironmentautoitemizeO +b
 
 beginitemize[#1]
 marcel_autoitemize:n #2 
 enditemize
 

seq_new:N l__marcel_autoitemize_items_seq
seq_new:N l__marcel_autoitemize_items_nopar_seq
tl_new:N l__marcel_autoitemize_item_tl

cs_new_protected:Nn marcel_autoitemize:n
 
 % split the contents at item; this also removes blanks at either end
 seq_set_split:Nnn l__marcel_autoitemize_items_seq item #1 
 % remove the first (empty) item
 seq_pop_left:NN l__marcel_autoitemize_items_seq l_tmpa_tl
 % we need to remove trailing par tokens
 seq_clear:N l__marcel_autoitemize_items_nopar_seq
 seq_map_function:NN l__marcel_autoitemize_items_seq __marcel_autoitemize_purify:n
 % start the first item
 item
 % use the sequence, putting a semicolon and item between items
 seq_use:Nn l__marcel_autoitemize_items_nopar_seq ; item 
 % end up with a period
 .
 

cs_new_protected:Nn __marcel_autoitemize_purify:n
 
 tl_set:Nn l__marcel_autoitemize_item_tl #1 
 regex_replace_once:nnN s* cpar* Z l__marcel_autoitemize_item_tl
 seq_put_right:NV l__marcel_autoitemize_items_nopar_seq l__marcel_autoitemize_item_tl
 

ExplSyntaxOff

begindocument

beginautoitemize
 item One

 item Two
 item Three
endautoitemize

beginautoitemize[label=--]
 item One
 item Two
 item Three
endautoitemize

enddocument