feature: Vim help-tags picker (#117)

* feature: Vim help-tags picker

* fix: filtered results were wrong because of missing `entry.value`

* fix: filtered (Vim only help) items are listed in results as empty
entries.

* fix: avoid search history pollution by replacing / in cmd returned by taglist() with search()

* fix: improve search() formatting

* fix: escape tilde in search() command

* fix: improve help-preview

* fix: improve search()

* fix: search() string fixes.

* fix: use no magic to do magic

Co-authored-by: TJ DeVries <devries.timothyj@gmail.com>

1 files changed, 19 insertions, 11 deletions

diff --git a/lua/telescope/previewers.lua b/lua/telescope/previewers.lua
index f3f6261..e28adce 100644
--- a/lua/telescope/previewers.lua
+++ b/lua/telescope/previewers.lua
@@ -58,7 +58,7 @@ end
 local previewer_ns = vim.api.nvim_create_namespace('telescope.previewers')
 
 local with_preview_window = function(status, bufnr, callable)
-  if bufnr and vim.api.nvim_buf_call then
+  if bufnr and vim.api.nvim_buf_call and false then
     vim.api.nvim_buf_call(bufnr, callable)
   else
     return context_manager.with(function()
@@ -365,17 +365,17 @@ previewers.qflist = defaulter(function(opts)
   }
 end, {})
 
--- WIP
 previewers.help = defaulter(function(_)
   return previewers.new {
     preview_fn = function(_, entry, status)
       with_preview_window(status, nil, function()
-        local old_tags = vim.o.tags
-        vim.o.tags = vim.fn.expand("$VIMRUNTIME") .. '/doc/tags'
+        local special_chars = ":~^.?/%[%]%*"
 
-        local taglist = vim.fn.taglist('^' .. entry.value .. '$')
+        local escaped = vim.fn.escape(entry.value, special_chars)
+        local tagfile = vim.fn.expand("$VIMRUNTIME") .. '/doc/tags'
+        local taglist = vim.fn.taglist('^' .. escaped .. '$', tagfile)
         if vim.tbl_isempty(taglist) then
-          taglist = vim.fn.taglist(entry.value)
+          taglist = vim.fn.taglist(escaped, tagfile)
         end
 
         if vim.tbl_isempty(taglist) then
@@ -384,15 +384,23 @@ previewers.help = defaulter(function(_)
 
         local best_entry = taglist[1]
         local new_bufnr = vim.fn.bufnr(best_entry.filename, true)
-
         vim.api.nvim_buf_set_option(new_bufnr, 'filetype', 'help')
         vim.api.nvim_win_set_buf(status.preview_win, new_bufnr)
 
-        vim.cmd [["gg"]]
-        print(best_entry.cmd)
-        vim.cmd(string.format([[execute "%s"]], best_entry.cmd))
+        local search_query = best_entry.cmd
+
+        -- remove leading '/'
+        search_query = search_query:sub(2)
+
+        -- Set the query to "very nomagic".
+        -- This should make it work quite nicely given tags.
+        search_query = [[\V]] .. search_query
+
+        log.trace([[lua vim.fn.search("]], search_query, [[")]])
 
-        vim.o.tags = old_tags
+        vim.cmd "norm! gg"
+        vim.fn.search(search_query, "W")
+        vim.cmd "norm  zt"
       end)
     end
   }