We can now follow tags

.luacheckrc

@@ -14,7 +14,6 @@ ignore = {
 
 globals = {
   "_",
-  "vim",
   "TelescopeGlobalState",
   "_TelescopeConfigurationValues",
   "_TelescopeConfigurationPickers",

data/plenary/filetypes/telekasten.lua

@@ -1,5 +1,5 @@
 return {
     extension = {
-        ['md'] = 'telekasten'
+        ["md"] = "telekasten",
-    }
+    },
 }

lua/taglinks/taglinks.lua

@@ -0,0 +1,196 @@
+local M = {}
+
+M.is_tag_or_link_at = function(line, col, opts)
+    opts = opts or {}
+    local initial_col = col
+
+    local char
+    local is_tagline = opts.tag_notation == "yaml-bare"
+        and line:sub(1, 4) == "tags"
+
+    local seen_bracket = false
+    while col >= 1 do
+        char = line:sub(col, col)
+
+        if seen_bracket then
+            if char == "[" then
+                return "link", col + 2
+            end
+        end
+
+        if char == "[" then
+            seen_bracket = true
+        end
+
+        if is_tagline == true then
+            if char == " " or char == "\t" or char == "," or char == ":" then
+                if col ~= initial_col then
+                    return "tag", col + 1
+                end
+            end
+        else
+            if char == "#" and opts.tag_notation == "#tag" then
+                return "tag", col
+            end
+
+            if char == ":" and opts.tag_notation == ":tag:" then
+                return "tag", col
+            end
+        end
+
+        if char == " " or char == "\t" then
+            return nil, nil
+        end
+        col = col - 1
+    end
+    return nil, nil
+end
+
+M.get_tag_at = function(line, col, opts)
+    -- we ignore the rule: no tags begin with a numeric digit
+    local endcol = col + 1
+    local pattern = "[%w-_/]"
+    local char
+    while endcol <= #line do
+        char = line:sub(endcol, endcol)
+        if char:match(pattern) == nil then
+            if opts.tag_notation == ":tag:" then
+                if char == ":" then
+                    local tag = line:sub(col, endcol)
+                    return tag
+                end
+            else
+                return line:sub(col, endcol - 1)
+            end
+        end
+        endcol = endcol + 1
+    end
+    -- we exhausted the line
+    return line:sub(col, endcol)
+end
+
+-------------
+-- testing --
+-------------
+
+local function _eval(line, col, opts)
+    local kind, newcol = M.is_tag_or_link_at(line, col, opts)
+    return { kind = kind, col = newcol, line = line }
+end
+
+local function _print_debug(x, prefix)
+    prefix = prefix or ""
+    for k, v in pairs(x) do
+        print(prefix .. k .. ": " .. tostring(v))
+    end
+end
+
+local function _expect(x, y)
+    for k, v in pairs(y) do
+        if x[k] ~= v then
+            print("expected:")
+            _print_debug(y, "  ")
+            print("got:")
+            _print_debug(x, "  ")
+            assert(false)
+        end
+    end
+end
+
+M._testme = function()
+    local line = ""
+    local col = 10
+    local opts = {}
+    local tag
+    local ret
+    assert(_eval(line, col, opts).kind == nil)
+
+    -- #tags
+    opts.tag_notation = "#tag"
+
+    line = "this is a #tag in a line"
+
+    -- lets find it
+    col = 13
+    _expect(_eval(line, col, opts), { col = 11, kind = "tag" })
+    ret = _eval(line, col, opts)
+    tag = M.get_tag_at(line, ret.col, opts)
+    -- print('tag .. `' .. tag .. '`')
+    assert(tag == "#tag")
+
+    -- lets be in the space after
+    col = 15
+    _expect(_eval(line, col, opts), { col = nil, kind = nil })
+
+    -- lets be in the next word
+    col = 16
+    _expect(_eval(line, col, opts), { col = nil, kind = nil })
+
+    -- lets be in the prev word
+    col = 9
+    _expect(_eval(line, col, opts), { col = nil, kind = nil })
+
+    -- lets change the tag notation but hit the tag col
+    col = 13
+    opts.tag_notation = ":tag:"
+    _expect(_eval(line, col, opts), { col = nil, kind = nil })
+
+    -- :tags:
+    opts.tag_notation = ":tag:"
+
+    line = "this is a :tag: in a line"
+
+    -- lets find it
+    col = 13
+    _expect(_eval(line, col, opts), { col = 11, kind = "tag" })
+    ret = _eval(line, col, opts)
+    tag = M.get_tag_at(line, ret.col, opts)
+    assert(tag == ":tag:")
+
+    -- lets be in the space after
+    col = 16
+    _expect(_eval(line, col, opts), { col = nil, kind = nil })
+
+    -- lets be in the next word
+    col = 17
+    _expect(_eval(line, col, opts), { col = nil, kind = nil })
+
+    -- lets be in the prev word
+    col = 9
+    _expect(_eval(line, col, opts), { col = nil, kind = nil })
+
+    -- lets change the tag notation but hit the tag col
+    col = 13
+    opts.tag_notation = "#tag"
+    _expect(_eval(line, col, opts), { col = nil, kind = nil })
+
+    -- tagline
+    line = "tags: [ first, second, third]"
+    opts.tag_notation = "yaml-bare"
+
+    col = 13
+    _expect(_eval(line, col, opts), { col = 9, kind = "tag" })
+    ret = _eval(line, col, opts)
+    tag = M.get_tag_at(line, ret.col, opts)
+    assert(tag == "first")
+
+    col = 9
+    _expect(_eval(line, col, opts), { col = 9, kind = "tag" })
+
+    col = 14
+    _expect(_eval(line, col, opts), { col = nil, kind = nil })
+
+    col = 18
+    _expect(_eval(line, col, opts), { col = 16, kind = "tag" })
+
+    --
+    line = "this is a [[link]] line"
+    col = 13
+    _expect(_eval(line, col, opts), { col = 13, kind = "link" })
+
+    line = "this is a [[link]] line"
+    col = 15
+    _expect(_eval(line, col, opts), { col = 13, kind = "link" })
+end
+
+return M

lua/telekasten.lua

@@ -10,6 +10,7 @@ local previewers = require("telescope.previewers")
 local make_entry = require("telescope.make_entry")
 local debug_utils = require("plenary.debug_utils")
 local filetype = require("plenary.filetype")
+local taglinks = require("taglinks/taglinks")
 
 -- declare locals for the nvim api stuff to avoid more lsp warnings
 local vim = vim
@@ -61,7 +62,11 @@ M.Cfg = {
     },
     close_after_yanking = false,
     insert_after_inserting = true,
+
     install_syntax = true,
+
+    -- tag notation: '#tag', ':tag:', 'yaml-bare'
+    tag_notation = "#tag",
 }
 
 local function file_exists(fname)
@@ -659,6 +664,13 @@ local function resolve_link(title)
     return fexists, filename
 end
 
+-- local function check_for_link_or_tag()
+local function check_for_link_or_tag()
+    local line = vim.api.nvim_get_current_line()
+    local col = vim.fn.col(".")
+    return taglinks.is_tag_or_link_at(line, col, M.Cfg)
+end
+
 --
 -- FollowLink:
 -- -----------
@@ -672,13 +684,29 @@ local function FollowLink(opts)
     opts.close_after_yanking = opts.close_after_yanking
         or M.Cfg.close_after_yanking
 
-    vim.cmd("normal yi]")
-    local title = vim.fn.getreg('"0')
-    title = title:gsub("^(%[)(.+)(%])$", "%2")
     local search_mode = "files"
+    local title
+    local filename = ""
+    local fexists
+
+    -- first: check if we're in a tag or a link
+    local kind, atcol = check_for_link_or_tag()
+
+    if kind == "tag" then
+        local tag = taglinks.get_tag_at(
+            vim.api.nvim_get_current_line(),
+            atcol,
+            M.Cfg
+        )
+        search_mode = "tag"
+        title = tag
+    else
+        -- we are in a link
+        vim.cmd("normal yi]")
+        title = vim.fn.getreg('"0')
+        title = title:gsub("^(%[)(.+)(%])$", "%2")
 
         local parts = vim.split(title, "#")
-    local filename = ""
 
         -- if there is a #
         if #parts ~= 1 then
@@ -691,9 +719,6 @@ local function FollowLink(opts)
                 title = parts[2]
             end
         end
-
-    local fexists
-
         if #filename > 0 then
             fexists, filename = resolve_link(filename)
             if fexists == false then
@@ -701,6 +726,7 @@ local function FollowLink(opts)
                 filename = ""
             end
         end
+    end
 
     if search_mode == "files" then
         -- check if fname exists anywhere
@@ -766,6 +792,16 @@ local function FollowLink(opts)
                 }
             end
 
+            if search_mode == "tag" then
+                search_command = {
+                    "rg",
+                    "--vimgrep",
+                    "-e",
+                    prompt,
+                    "--",
+                }
+            end
+
             if #filename > 0 then
                 table.insert(search_command, filename)
             else
@@ -1521,5 +1557,6 @@ M.find_friends = FindFriends
 M.insert_img_link = InsertImgLink
 M.preview_img = PreviewImg
 M.browse_media = BrowseImg
+M.taglinks = taglinks
 
 return M