Create `s:FilterTabPageElements()`

Add a function that will filter out "Tab page 10" elements that don't
have any files under them.

Incomplete for now but I'm committing what I have here because it looks
like I'm going to have to change things around just a bit.

At the moment, the function will take the list of matched `:tabs` lines,
make a list of the indexes of the "Tab page X" elements, and finally
remove the empty "Tab page X" elements from that list, leaving only the
indexes of those with files under them.

Instead what I think I need is a list of the "Tab page X" indexes that
don't have files so I can remove these from the list.

1 files changed, 45 insertions, 0 deletions

diff --git a/plugin/tabs_grep.vim b/plugin/tabs_grep.vim
index 8b98f1b..70e7bce 100644
--- a/plugin/tabs_grep.vim
+++ b/plugin/tabs_grep.vim
@@ -10,6 +10,8 @@ function! TabsGrep(search)
 	call filter(tabs, function('s:MatchString', [a:search]))
 	echo tabs
 
+	call s:FilterTabPageElements(tabs)
+
 	" let filtered_tabs = system(
 	" 	\ 'echo '
 	" 	\ . shellescape(tabs_output)
@@ -25,4 +27,47 @@ function! s:MatchString(search, index, value)
 		\ match(a:value, '\vTab page \d+') != -1
 endfunction
 
+function! s:IsTabPageLine(line)
+	return match(a:line, '\vTab page \d+') != -1
+endfunction
+
+function! s:FilterTabPageElements(list)
+	" Has matches:
+	" [0, 1, 1, 0, 0]
+	"
+	" Tab page line indexes:
+	" [1, 2, 4, 6, 7, 8]
+	"
+	" Tab page line indexes with matches:
+	" [2, 4]
+
+	let tab_page_indexes = []
+
+	for i in range(len(a:list))
+		if s:IsTabPageLine(a:list[i])
+			call add(tab_page_indexes, i)
+		endif
+	endfor
+
+	echo tab_page_indexes
+
+	" loop 1..-1
+	" if l[i-1] == l[i] - 1
+	" delete l[i-1]
+	" if last l == len l - 1
+	" delete last l
+
+	let filtered_tab_page_indexes = copy(tab_page_indexes)
+
+	for i in range(1, len(tab_page_indexes) - 1)
+		if tab_page_indexes[i - 1] == tab_page_indexes[i] - 1
+			call remove(filtered_tab_page_indexes, i - 1)
+		endif
+	endfor
+
+	if filtered_tab_page_indexes[-1] == len(a:list) - 1
+		call remove(filtered_tab_page_indexes, -1)
+	endif
+endfunction
+
 command! -nargs=1 TabsGrep :call TabsGrep(<f-args>)