1 files changed, 101 insertions, 0 deletions
diff --git a/Data/Libraries/LDoc/tests/styles/priority_queue.lua b/Data/Libraries/LDoc/tests/styles/priority_queue.lua
new file mode 100644
index 0000000..9dcc5ad
--- /dev/null
+++ b/Data/Libraries/LDoc/tests/styles/priority_queue.lua
@@ -0,0 +1,101 @@
+--------------------------------------------------------------------------------
+--- Queue of objects sorted by priority.
+-- @module lua-nucleo.priority_queue
+-- This file is a part of lua-nucleo library. Note that if you wish to spread
+-- the description after tags, then invoke with `not_luadoc=true`. 
+-- The flags here are `ldoc -X -f backtick priority_queue.lua`, which
+-- also expands backticks.
+-- @copyright lua-nucleo authors (see file `COPYRIGHT` for the license)
+--------------------------------------------------------------------------------
+
+local arguments,
+      method_arguments
+      = import 'lua-nucleo/args.lua'
+      {
+        'arguments',
+        'method_arguments'
+      }
+
+local lower_bound_gt
+      = import 'lua-nucleo/algorithm.lua'
+      {
+        'lower_bound_gt'
+      }
+
+--------------------------------------------------------------------------------
+
+local table_insert, table_remove = table.insert, table.remove
+
+--------------------------------------------------------------------------------
+
+--- Priority Queue
+-- @factory priority_queue
+local make_priority_queue
+do
+  local PRIORITY_KEY = 1
+  local VALUE_KEY = 2
+
+  local insert = function(self, priority, value)
+    method_arguments(
+        s
+        "number", priority
+      )
+    assert(value ~= nil, "value can't be nil") -- value may be of any type, except nil
+
+    local queue = self.queue_
+    local k = lower_bound_gt(queue, PRIORITY_KEY, priority)
+
+    table_insert(queue, k, { [PRIORITY_KEY] = priority, [VALUE_KEY] = value })
+  end
+
+  local front = function(self)
+    method_arguments(
+        self
+      )
+
+    local queue = self.queue_
+    local front_elem = queue[#queue]
+
+    if front_elem == nil then
+      return nil
+    end
+
+    return front_elem[PRIORITY_KEY], front_elem[VALUE_KEY]
+  end
+
+  --- pop last value.
+  -- @return priority
+  -- @return value
+  local pop = function(self)
+    method_arguments(
+        self
+      )
+
+    local front_elem = table_remove(self.queue_)
+
+    if front_elem == nil then
+      return nil
+    end
+
+    return front_elem[PRIORITY_KEY], front_elem[VALUE_KEY]
+  end
+
+  --- construct a `priority_queue`.
+  -- @constructor
+  make_priority_queue = function()
+    --- @export
+    return
+    {
+      insert = insert;
+      front = front;
+      pop = pop;
+      --
+      queue_ = { };
+    }
+  end
+end
+
+return
+{
+  make_priority_queue = make_priority_queue;
+}