diff --git a/lua/tsql.lua b/lua/tsql.lua
index caa63ce..e9b9d27 100644
--- a/lua/tsql.lua
+++ b/lua/tsql.lua
@@ -1,5 +1,4 @@
----TODO: how does this work with changing texts?
----TODO: add reducer as formatter
+---TODO: how does this work with changing texts? TODO: add reducer as formatter
 ---TODO: Add reducer as buf_select predicate
 
 ---@type mod_buf_select
@@ -96,12 +95,11 @@ function M.sink_by.print(format)
     if format == nil then
         format = M.format.default
     end
-    return setmetatable({
-        ---@type fun(nodes: QNode[])
-        sink = function(nodes)
+    return M.sink_by.pure_fn(
+        function(nodes)
             print(format(nodes))
         end
-    }, M.Sink)
+    )
 end
 
 ---@param format Format
@@ -110,13 +108,12 @@ function M.sink_by.nvim_yank_buf(format)
     if format == nil then
         format = M.format.default
     end
-    return setmetatable({
-        ---@type fun(nodes: QNode[])
-        sink = function(nodes)
+    return M.sink.pure_fn(
+        function(nodes)
             local text = format(nodes)
             vim.fn.setreg('"', text)
         end
-    }, M.Sink)
+    )
 end
 
 ---NOTE: re-export with implementation
@@ -155,9 +152,11 @@ end
 
 ---NOTE: requires nvim runtime
 function M.Tsql:q_nodes()
-    return self.codeql:find_nodes(
-        self.buf_match.filter_on(self.buf_match, M.nvim_get_qbufs())
-    )
+    return self.codeql:find_nodes(self:qbufs())
+end
+
+function M.Tsql:qbufs()
+    return self.buf_match.filter_on(self.buf_match, M.nvim_get_qbufs())
 end
 
 ---NOTE: This is now exiting the functional core and entering
@@ -220,7 +219,7 @@ end
 function M.Store:new()
     local o = { highlighting = {} }
     setmetatable(o, self)
-    self.__index = self
+    o.__index = self
     return o
 end
 
@@ -240,7 +239,6 @@ function M.setup(config)
     end, { nargs = "?", desc = "tsql DSL invocation" })
 
     M.store = M.Store:new()
-    print("tsql v0.0.1")
 end
 
 return M
diff --git a/lua/tsql/buf_select.lua b/lua/tsql/buf_select.lua
index e3812da..6a74c2d 100644
--- a/lua/tsql/buf_select.lua
+++ b/lua/tsql/buf_select.lua
@@ -11,9 +11,9 @@ local M = {}
 ---Assume [""] if it's erroneous (like a terminal buffer)
 ---@field filetype string the associated filetypes gotten from. This uses
 ---`vim.api.nvim_buf_get_option(bufnr: number, 'filetype')`
----@field lang string The language of the treesitter parser. This is gotten
----from `vim.treesitter.get_parser(bufnr: number):lang() -> string [may fail]`
----@field is_loaded boolean whether it is loaded
+---@field lang string | nil The language of the treesitter parser. This is gotten
+---from `pcall of vim.treesitter.get_parser(bufnr: number):lang() -> string | nil`
+---@field is_loaded boolean whether it is loaded (`vim.api.nvim_buf_is_loaded`)
 M.QBuf = {}
 M.QBuf.__index = M.QBuf
 
@@ -24,6 +24,7 @@ local function get_lang(bufnr)
         return vim.treesitter.get_parser(bufnr):lang()
     end)
 
+    -- PURPOSE: enriches the message
     if not status then
         local path = vim.api.nvim_buf_get_name(bufnr)
         error(string.format("Error determining language for buffer %d: %s", bufnr, path))
@@ -35,15 +36,13 @@ end
 ---@param bufnr number
 ---@param path string
 ---@param filetype string
----@param lang string
+---@param lang string | nil
 ---@param is_loaded boolean
 ---@return QBuf
 function M.QBuf:new(bufnr, path, filetype, lang, is_loaded)
     assert(type(bufnr) == "number", "bufnr must be a number")
     assert(type(path) == "string", "path must be a string")
     assert(type(filetype) == "string", "filetype must be a string")
-    assert(type(lang) == "string", "lang must be a string")
-    assert(type(is_loaded) == "boolean", "is_loaded must be a boolean")
 
     local qbuf = {
         bufnr = bufnr,
@@ -58,14 +57,33 @@ function M.QBuf:new(bufnr, path, filetype, lang, is_loaded)
 end
 
 ---@param bufnr number
+---@return QBuf | nil
 function M.QBuf.from_nvim_bufnr(bufnr)
     local path = vim.api.nvim_buf_get_name(bufnr)
     local filetype = vim.api.nvim_buf_get_option(bufnr, 'filetype')
 
-    local status, lang = pcall(get_lang, bufnr)
-    local is_loaded = status
+    assert(type(filetype) == "string")
 
-    return M.QBuf:new(bufnr, path, filetype, lang, is_loaded)
+    if #filetype == 0 then
+        return nil
+    end
+
+    local sts, _lang = pcall(get_lang, bufnr)
+    ---@type nil | string
+    local lang = nil
+    if sts then
+        lang = _lang
+    end
+
+    local is_loaded = vim.api.nvim_buf_is_loaded(bufnr)
+
+    return M.QBuf:new(
+        bufnr,
+        path,
+        filetype,
+        lang,
+        is_loaded
+    )
 end
 
 M.buf_match = {}
@@ -75,6 +93,7 @@ M.buf_match = {}
 ---@field then_ fun(self, q: BufMatch): BufMatch
 ---@field filter_on fun(self, q: QBuf[]): QBuf[]
 M.BufMatch = {}
+M.BufMatch.__index = M.BufMatch
 
 function M.buf_match.is_loaded()
     return M.BufMatch.new(function(buf)
@@ -201,27 +220,16 @@ local function list_bufs()
     return vim.api.nvim_list_bufs()
 end
 
----@return QBuf[]
+---@return QBuf[] qbufs
 function M.nvim_get_qbufs()
     local bufnrs = list_bufs()
     local qbufs = {}
 
     for _, bufnr in ipairs(bufnrs) do
-        local path = vim.api.nvim_buf_get_name(bufnr)
-        local filetype = vim.api.nvim_buf_get_option(bufnr, 'filetype')
-
-        local status, lang = pcall(get_lang, bufnr)
-        local is_loaded = status
-
-        local qbuf = {
-            bufnr = bufnr,
-            path = path,
-            filetype = filetype,
-            lang = lang,
-            is_loaded = is_loaded
-        }
-
-        table.insert(qbufs, qbuf)
+        local qbuf = M.QBuf.from_nvim_bufnr(bufnr)
+        if qbuf ~= nil then
+            table.insert(qbufs, qbuf)
+        end
     end
 
     return qbufs
diff --git a/lua/tsql/token_select.lua b/lua/tsql/token_select.lua
index ef19eed..37ad6ba 100644
--- a/lua/tsql/token_select.lua
+++ b/lua/tsql/token_select.lua
@@ -7,6 +7,15 @@ M.ts_query = {}
 ---@class TSQuery
 ---@field query string the passthru for treesitter language parser
 M.TSQuery = {}
+M.TSQuery.__index = M.TSQuery
+
+---@type Ctor<{query: string}, TSQuery>
+function M.TSQuery.new(q)
+    local self = q
+    setmetatable(self, M.TSQuery)
+    self.__index = M.TSQuery
+    return self
+end
 
 ---@class FileLoc
 ---@field row_0 number 0-index row location
@@ -14,6 +23,15 @@ M.TSQuery = {}
 M.FileLoc = {}
 M.FileLoc.__index = M.FileLoc
 
+---@type Ctor<{row_0: number, col_0: number}, FileLoc>
+function M.FileLoc.new(file_loc)
+    assert(file_loc ~= nil)
+    local self = file_loc
+    setmetatable(self, M.FileLoc)
+    self.__index = M.FileLoc
+    return self
+end
+
 ---@class QNode
 ---@field start FileLoc
 ---@field end_ex_col FileLoc
@@ -21,11 +39,20 @@ M.FileLoc.__index = M.FileLoc
 M.QNode = {}
 M.QNode.__index = M.QNode
 
+---@type Ctor<{start: FileLoc, end_ex_col: FileLoc, buf: QBuf}, QNode>
+function M.QNode.new(qnode)
+    assert(qnode ~= nil)
+    local self = qnode
+    setmetatable(self, M.QNode)
+    self.__index = M.QNode
+    return self
+end
+
 ---@param treesitter_query string the passthru for treesitter language
 ---parser
 ---@return TSQuery
 function M.ts_query.from_scm(treesitter_query)
-    return {
+    return M.TSQuery.new {
         query = treesitter_query
     }
 end
@@ -35,23 +62,35 @@ end
 function M.TSQuery:find_nodes(files)
     local result = {}
     for _, file in ipairs(files) do
-        local parser = vim.treesitter.get_parser(file.bufnr, file.filetype)
+        if file.lang == nil then
+            goto continue
+        end
+        local sts, parser = pcall(vim.treesitter.get_parser, file.bufnr, file.filetype)
+        if not sts then
+            -- NOTE: no parser for language
+            goto continue
+        end
         local tree = parser:parse()[1]
         local root = tree:root()
         ---@type Query
-        local query = vim.treesitter.query.parse_query(file.lang, self.query)
+        local sts, query = pcall(vim.treesitter.query.parse, file.lang, self.query)
+        if not sts then
+            error("Error parsing query \"" .. self.query .. "\" on lang " .. file.lang .. " for file " .. file.path)
+        end
+
         for _, match, _ in query:iter_matches(root, file.bufnr, 0, -1) do
             for id, node in pairs(match) do
                 local start_row, start_col, end_row, end_col = node:range(false)
-                local start = { row_0 = start_row, col_0 = start_col }
+                local start = M.FileLoc.new { row_0 = start_row, col_0 = start_col }
                 -- CORRECTNESS:
                 -- :lua local parser = vim.treesitter.get_parser(0, 'lua'); local tree = parser:parse()[1]; local query = vim.treesitter.parse_query('lua', '(identifier) @name'); for id, node in query:iter_captures(tree:root(), 0) do local name = query.captures[id]; if name == 'name' and vim.treesitter.get_node_text(node, 0) == 'TSQuery' then local sr, sc, er, ec = node:range(); print(string.format("TSQuery Start: (%d, %d), End: (%d, %d)", sr, sc, er, ec)); end; end
-                local end_ex_col = { row_0 = end_row, col_0 = end_col }
-                local qnode = { buf = file, start = start, end_ex_col = end_ex_col }
-                setmetatable(qnode, M.QNode)
+                local end_ex_col = M.FileLoc.new { row_0 = end_row, col_0 = end_col }
+                local qnode = M.QNode.new { buf = file, start = start, end_ex_col = end_ex_col }
+
                 table.insert(result, qnode)
             end
         end
+        ::continue::
     end
     return result
 end
diff --git a/repl.md b/repl.md
index 5068a1c..93923d9 100644
--- a/repl.md
+++ b/repl.md
@@ -1,13 +1,30 @@
 # Simple location for me to use as a neovim repl
 
 ```lua
-:lua local ts = require('tsql'); ts.t(ts.buf_match.any(), ts.ts_query.from_scm("string"), ts.sink_by.print()):do_nvim();
-
-:lua local ts = require('tsql'); local tsql = ts.t(ts.buf_match.any(), ts.ts_query.from_scm("string"), ts.sink_by.print()); print(vim.inspect(tsql.buf_match));
-
--- print found bufs
-:lua local t = require('tsql'); print(vim.inspect(t.nvim_get_qbufs()))
-
--- check that buf filter works
-:lua local t = require('tsql'); print(vim.inspect(t.buf_match.any():filter_on(t.nvim_get_qbufs())))
+:lua local ts = require('tsql'); ts.t(ts.buf_match.filetype("lua"), ts.ts_query.from_scm("(string) @_"), ts.sink_by.print()):do_nvim(ts.store);
+:lua local ts = require('tsql'); ts.t(ts.buf_match.filetype("lua"), ts.ts_query.from_scm("(string) @_"), ts.sink_by.highlight()):do_nvim(ts.store);
+:Noh
+-- QNodes from current buffer
+:lua local ts = require('tsql'); print(vim.inspect(ts.ts_query.from_scm("(string) @_"):find_nodes({ts.QBuf.from_nvim_bufnr(0)})))
+```
+
+Non-tsql poc
+```lua
+:lua local parser = vim.treesitter.get_parser(0, 'lua'); local tree = parser:parse()[1]; local query = vim.treesitter.parse_query('lua', '(identifier) @name'); for id, node in query:iter_captures(tree:root(), 0) do local name = query.captures[id]; if name == 'name' and vim.treesitter.get_node_text(node, 0) == 'TSQuery' then local sr, sc, er, ec = node:range(); print(string.format("TSQuery Start: (%d, %d), End: (%d, %d)", sr, sc, er, ec)); end; end
+
+```
+
+
+```lua
+:lua local ts = require('tsql'); ts.t(ts.buf_match.filetype("lua"), ts.ts_query.from_scm("(string) @_"), ts.sink_by.highlight()):do_nvim(ts.store);
+:lua local ts = require('tsql'); ts.t(ts.buf_match.filetype("lua"), ts.ts_query.from_scm("(identifier) @_"), ts.sink_by.highlight()):do_nvim(ts.store);
+-- Highlight all function calls `hello.world("what the heck!")`
+:lua local ts = require('tsql'); ts.t(ts.buf_match.filetype("lua"), ts.ts_query.from_scm("(function_call) @_"), ts.sink_by.highlight()):do_nvim(ts.store);
+-- Highlight only function calls that are "pure": Not `hello.world` but `world`
+:lua local ts = require('tsql'); ts.t(ts.buf_match.filetype("lua"), ts.ts_query.from_scm("(function_call (identifier) @_)"), ts.sink_by.highlight()):do_nvim(ts.store);
+-- Highlight function calls, but only the function identifier
+:lua local ts = require('tsql'); ts.t(ts.buf_match.filetype("lua"), ts.ts_query.from_scm("[(function_call name: (dot_index_expression) @_) (function_call name: (identifier) @_) (function_call name: (method_index_expression) @_)]"), ts.sink_by.highlight()):do_nvim(ts.store);
+
+:Noh
+
 ```