feat: add :Noh

lua/tsql.lua

@@ -1,3 +1,7 @@
+---TODO: how does this work with changing texts?
+---TODO: add reducer as formatter
+---TODO: Add reducer as buf_select predicate
+
 ---@type mod_buf_select
 local buf_select = require('tsql.buf_select')
 ---@type mod_token_select
@@ -13,9 +17,6 @@ M.sink_by = {}
 ---@alias Format fun(nodes: QNode[]): string
 M.format = {}
 
-M.nvim_ns = vim.api.nvim_create_namespace("tsql")
-M.nvim_hl_group = "Search"
-
 ---@class Sink
 ---@field sink fun(self, nodes: QNode[])
 M.Sink = {}
@@ -29,8 +30,8 @@ function M.sink_by.highlight()
             for _, node in ipairs(nodes) do
                 vim.highlight.range(
                     node.buf.bufnr,
-                    M.nvim_ns,
+                    M.config.nvim_ns,
-                    M.nvim_hl_group,
+                    M.config.nvim_hl_group,
                     { node.start.row_0, node.start.col_0 },
                     { node.end_ex_col.row_0, node.end_ex_col.col_0 },
                     {}
@@ -128,14 +129,88 @@ function M.t(buf_match, codeql, sink)
     }, M.Tsql)
 end
 
----NOTE: This is now exiting the functional core and entering
+---NOTE: requires nvim runtime
---- imperative shell
+function M.Tsql:q_nodes()
-function M.Tsql:do_nvim()
+    return self.codeql:find_nodes(
-    self.sink:sink(
-        self.codeql:find_nodes(
         self.buf_match:filter_on(M.nvim_get_qbufs())
     )
-    )
+end
+
+---NOTE: This is now exiting the functional core and entering
+--- imperative shell
+--- @param store StaticStore
+function M.Tsql:do_nvim(store)
+    self.sink:sink(self:q_nodes())
+    store:add_highlight(self)
+end
+
+---@param config RtConfig
+---@param store StaticStore
+function M._delete_all_highlights(config, store)
+    ---@type table<integer, QBuf>
+    local bufs = {}
+    for _, highlight_q in pairs(store.highlighting) do
+        for _, qnode in ipairs(highlight_q:q_nodes()) do
+            table.insert(bufs, qnode.buf.bufnr, qnode.buf)
+        end
+    end
+
+    for _, buf in pairs(bufs) do
+        vim.api.nvim_buf_clear_namespace(buf.bufnr, config.nvim_ns, 0, -1)
+    end
+    store:clear_highlights()
+end
+
+---NOTE: Collocated with `M.setup`
+---@class Config
+---@field nvim_hl_group string
+local Config = {}
+---@type Config
+M.config_default = {
+    nvim_hl_group = "Search"
+}
+
+---@class RtConfig: Config
+---@field nvim_ns number
+M.RtConfig = {}
+---@type RtConfig
+M.config = {}
+
+---@class StaticStore
+---@field highlighting Tsql[]
+---This is needed to undo the highlighting done by this plugin and potentially
+---subscribe to the changing buffers to re-highlight if necessary
+M.Store = {}
+M.Store.__index = M.Store
+
+---@param tsql Tsql
+function M.Store:add_highlight(tsql)
+    table.insert(self.highlighting, tsql)
+end
+
+function M.Store:clear_highlights()
+    self.highlighting = {}
+end
+
+---@return StaticStore
+function M.Store:new()
+    local o = { highlighting = {} }
+    setmetatable(o, self)
+    return o
+end
+
+function M.clear_highlights()
+    return M._delete_all_highlights(M.config, M.store)
+end
+
+---@param config Config
+function M.setup(config)
+    M.config = vim.tbl_deep_extend("force", M.config, config or M.config_default)
+    M.config.nvim_ns = vim.api.nvim_create_namespace("tsql")
+
+    vim.api.nvim_create_user_command("Noh", M.clear_highlights)
+
+    M.store = M.Store:new()
 end
 
 return M

lua/tsql/sink.lua

@@ -1,14 +0,0 @@
-local M = {}
-
-M.Sink = {}
-
-function M.print()
-end
-
-function M.highlight()
-end
-
-function M.mutate()
-end
-
-return M