feat: Add folding

lua/symbols-outline/parser.lua

@@ -2,6 +2,7 @@ local symbols = require 'symbols-outline.symbols'
 local ui = require 'symbols-outline.ui'
 local config = require 'symbols-outline.config'
 local t_utils = require 'symbols-outline.utils.table'
+local folding = require 'symbols-outline.folding'
 
 local M = {}
 
@@ -9,8 +10,9 @@ local M = {}
 ---@param result table The result from a language server.
 ---@param depth number? The current depth of the symbol in the hierarchy.
 ---@param hierarchy table? A table of booleans which tells if a symbols parent was the last in its group.
+---@param parent table? A reference to the current symbol's parent in the function's recursion
 ---@return table
-local function parse_result(result, depth, hierarchy)
+local function parse_result(result, depth, hierarchy, parent)
   local ret = {}
 
   for index, value in pairs(result) do
@@ -24,14 +26,6 @@ local function parse_result(result, depth, hierarchy)
       -- whether this node is the last in its group
       local isLast = index == #result
 
-      local children = nil
-      if value.children ~= nil then
-        -- copy by value because we dont want it messing with the hir table
-        local child_hir = t_utils.array_copy(hir)
-        table.insert(child_hir, isLast)
-        children = parse_result(value.children, level + 1, child_hir)
-      end
-
       -- support SymbolInformation[]
       -- https://microsoft.github.io/language-server-protocol/specification#textDocument_documentSymbol
       local selectionRange = value.selectionRange
@@ -44,7 +38,7 @@ local function parse_result(result, depth, hierarchy)
         range = value.location.range
       end
 
-      table.insert(ret, {
+      local node = {
         deprecated = value.deprecated,
         kind = value.kind,
         icon = symbols.icon_from_kind(value.kind),
@@ -54,11 +48,24 @@ local function parse_result(result, depth, hierarchy)
         character = selectionRange.start.character,
         range_start = range.start.line,
         range_end = range['end'].line,
-        children = children,
         depth = level,
         isLast = isLast,
         hierarchy = hir,
-      })
+        parent = parent,
+      }
+
+      table.insert(ret, node)
+
+      local children = nil
+      if value.children ~= nil then
+        -- copy by value because we dont want it messing with the hir table
+        local child_hir = t_utils.array_copy(hir)
+        table.insert(child_hir, isLast)
+        children = parse_result(value.children, level + 1, child_hir, node)
+      end
+
+      node.children = children
+
     end
   end
   return ret
@@ -139,14 +146,23 @@ function M.parse(response)
   return parse_result(sorted, nil, nil)
 end
 
-function M.flatten(outline_items, ret)
+function M.flatten(outline_items, ret, depth)
+  depth = depth or 1
   ret = ret or {}
   for _, value in ipairs(outline_items) do
     table.insert(ret, value)
-    if value.children ~= nil then
-      M.flatten(value.children, ret)
+    value.line_in_outline = #ret
+    if value.children ~= nil and not folding.is_folded(value) then
+      M.flatten(value.children, ret, depth + 1)
     end
   end
+
+  -- if depth == 1 then
+  --   for index, value in ipairs(ret) do
+  --     value.line_in_outline = index
+  --   end
+  -- end
+
   return ret
 end
 
@@ -155,7 +171,10 @@ function M.get_lines(flattened_outline_items)
   local hl_info = {}
 
   for node_line, node in ipairs(flattened_outline_items) do
-    local line = t_utils.str_to_table(string.rep(' ', node.depth))
+    local depth = node.depth
+    local marker_space = (config.options.fold_markers and 1) or 0
+
+    local line = t_utils.str_to_table(string.rep(' ', depth + marker_space))
     local running_length = 1
 
     local function add_guide_hl(from, to)
@@ -176,27 +195,43 @@ function M.get_lines(flattened_outline_items)
           -- i f index is last, add a bottom marker if current item is last,
           -- else add a middle marker
         elseif index == #line then
-          if node.isLast then
-            line[index] = ui.markers.bottom
+          -- add fold markers
+          if config.options.fold_markers and folding.is_foldable(node) then
+            if folding.is_folded(node) then
+              line[index] = config.options.fold_markers[1]
+            else
+              line[index] = config.options.fold_markers[2]
+            end
+
             add_guide_hl(
               running_length,
-              running_length + vim.fn.strlen(ui.markers.bottom) - 1
-            )
-          else
-            line[index] = ui.markers.middle
-            add_guide_hl(
-              running_length,
-              running_length + vim.fn.strlen(ui.markers.middle) - 1
+              running_length + vim.fn.strlen(line[index]) - 1
             )
+
+            -- the root level has no vertical markers
+          elseif depth > 1 then
+            if node.isLast then
+              line[index] = ui.markers.bottom
+              add_guide_hl(
+                running_length,
+                running_length + vim.fn.strlen(ui.markers.bottom) - 1
+              )
+            else
+              line[index] = ui.markers.middle
+              add_guide_hl(
+                running_length,
+                running_length + vim.fn.strlen(ui.markers.middle) - 1
+              )
+            end
           end
           -- else if the parent was not the last in its group, add a
           -- vertical marker because there are items under us and we need
           -- to point to those
-        elseif not node.hierarchy[index] then
-          line[index] = ui.markers.vertical
+        elseif not node.hierarchy[index] and depth > 1 then
+          line[index + marker_space] = ui.markers.vertical
           add_guide_hl(
-            running_length,
-            running_length + vim.fn.strlen(ui.markers.vertical) - 1
+            running_length - 1 + 2*marker_space,
+            running_length + vim.fn.strlen(ui.markers.vertical) - 1 + 2 * marker_space
           )
         end
       end