feat: add option for hiding lines

README.md

@@ -373,6 +373,7 @@ require'treesitter-context'.setup{
   separator = nil,
   zindex = 20, -- The Z-index of the context window
   on_attach = nil, -- (fun(buf: integer): boolean) return false to disable attaching
+  hide_lines = nil, -- Lines matching the regex will not be displayed. Example for hiding single '{': "^%s*{%s*$"
 }
 ```
 

lua/treesitter-context/config.lua

@@ -10,6 +10,7 @@
 --- @field mode 'cursor'|'topline'
 --- @field separator? string
 --- @field on_attach? fun(buf: integer): boolean
+--- @field hide_lines? string
 
 --- @class (exact) TSContext.UserConfig : TSContext.Config
 ---
@@ -45,6 +46,10 @@
 ---
 --- Callback when attaching. Return false to disable attaching
 --- @field on_attach? fun(buf: integer): boolean
+---
+--- Regular expression for hiding undesired lines in the context window, like single '{'.
+--- Lines that match regex will be hidden.
+--- @field hide_lines? string
 
 --- @type TSContext.Config
 local default_config = {
@@ -57,6 +62,7 @@ local default_config = {
   trim_scope = 'outer',
   zindex = 20,
   mode = 'cursor',
+  hide_lines = nil,
 }
 
 local config = vim.deepcopy(default_config)

lua/treesitter-context/context.lua

@@ -224,6 +224,28 @@ local function get_text_for_range(range, bufnr)
   return { start_row, 0, end_row, end_col }, lines
 end
 
+--- In-place drop lines that match `config.hide_lines`.
+--- @param range Range4
+--- @param lines string[]
+local function line_filter(range, lines)
+  local regex = config.hide_lines
+  if regex == nil then
+    return
+  end
+  local no_dropped = 0
+  for i, line in ipairs(lines) do
+    if line:match(regex) then
+      no_dropped = no_dropped + 1
+    else
+      lines[i - no_dropped] = lines[i]
+    end
+  end
+  for i = 1, no_dropped do
+    lines[#lines] = nil
+  end
+  range[3] = range[3] - no_dropped
+end
+
 local M = {}
 
 --- @param bufnr integer
@@ -377,6 +399,7 @@ function M.get(winid)
           local range0 = context_range(parent, bufnr, query)
           if range0 and range_is_valid(range0) then
             local range, lines = get_text_for_range(range0, bufnr)
+            line_filter(range, lines)
             if range_is_valid(range) then
               local last_context = context_ranges[#context_ranges]
               if last_context and parent_start_row == last_context[1] then