List.lua: add missing fixes as discussed in #4099

The changes were missing due to an error while using git.

data/List.lua

@@ -16,16 +16,11 @@ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
 THIS SOFTWARE.
 ]]
 
----
--- Lua functions for pandoc scripts.
---
+--- Pandoc's List type and helper methods
+-- @classmod pandoc.List
 -- @author Albert Krewinkel
 -- @copyright © 2017 Albert Krewinkel
 -- @license MIT
-
-------------------------------------------------------------------------
--- Metatable for lists
--- @type List
 local List = {
   _VERSION = "0.1.0"
 }
@@ -42,6 +37,8 @@ function List:__call (o)
 end
 
 --- Concatenates two lists.
+-- @param list second list concatenated to the first
+-- @return a new list containing all elements from list1 and list2
 function List:__concat (list)
   local res = List.clone(self)
   List.extend(res, list)
@@ -55,40 +52,40 @@ function List:clone ()
   return lst
 end
 
---- Appends the given list to the end of this list.
-function List:includes (needle)
-  for i = 1, #self do
-    if self[i] == needle then
-      return true
-    end
-  end
-  return false
+--- Checks if the list has an item equal to the given needle.
+-- @param needle item to search for
+-- @param init index at which the search is started
+-- @return true if a list item is equal to the needle, false otherwise
+function List:includes (needle, init)
+  return not (List.find(self, needle, init) == nil)
 end
 
 --- Returns the value and index of the first occurrence of the given item.
 -- @param needle item to search for
+-- @param init index at which the search is started
 -- @return first item equal to the needle, or nil if no such item exists.
 -- @return index of that element
 function List:find (needle, init)
   return List.find_if(self, function(x) return x == needle end, init)
 end
 
---- Returns the value and index of the first element for which test returns true.
--- @param test the test function
+--- Returns the value and index of the first element for which the predicate
+--- holds true.
+-- @param pred the predicate function
 -- @param init index at which the search is started
 -- @return first item for which `test` succeeds, or nil if no such item exists.
 -- @return index of that element
-function List:find_if (test, init)
+function List:find_if (pred, init)
   init = (init == nil and 1) or (init < 0 and #self - init) or init
   for i = init, #self do
-    if test(self[i], i) then
+    if pred(self[i], i) then
       return self[i], i
     end
   end
   return nil
 end
 
---- Add the given list to the end of this list.
+--- Adds the given list to the end of this list.
 -- @param list list to appended
 function List:extend (list)
   for i = 1, #list do
@@ -96,12 +93,26 @@ function List:extend (list)
   end
 end
 
--- Returns a copy of the current list by applying the given function to all
+--- Returns a copy of the current list by applying the given function to all
 -- elements.
+-- @param fn function which is applied to all list items.
 function List:map (fn)
   local res = setmetatable({}, getmetatable(self))
   for i = 1, #self do
-    res[i] = fn(self[i])
+    res[i] = fn(self[i], i)
+  end
+  return res
+end
+
+--- Returns a new list containing all items satisfying a given condition.
+-- @param pred condition items must satisfy.
+-- @return a new list containing all items for which `test` was true.
+function List:filter (pred)
+  local res = setmetatable({}, getmetatable(self))
+  for i = 1, #self do
+    if pred(self[i], i) then
+      res[#res + 1] = self[i]
+    end
   end
   return res
 end

data/pandoc.lua

@@ -26,7 +26,7 @@ local M = {
   _VERSION = "0.3.0"
 }
 
-local List = require 'List'
+local List = require 'pandoc.List'
 
 ------------------------------------------------------------------------
 -- The base class for pandoc's AST elements.

src/Text/Pandoc/Lua/PandocModule.hs

@@ -91,7 +91,7 @@ loadListModule :: Maybe FilePath -> Lua ()
 loadListModule datadir = do
   Lua.getglobal' "package.loaded"
   pushListModule datadir
-  Lua.setfield (-2) "List"
+  Lua.setfield (-2) "pandoc.List"
   Lua.pop 1
 
 walkElement :: (ToLuaStack a, Walkable [Inline] a, Walkable [Block] a)