new data type: set

1 files changed, 49 insertions, 0 deletions

diff --git a/acf/model/set.lua b/acf/model/set.lua
new file mode 100644
index 0000000..be6c2de
--- /dev/null
+++ b/acf/model/set.lua
@@ -0,0 +1,49 @@
+--[[
+Copyright (c) 2012-2013 Kaarle Ritvanen
+See LICENSE file for license details
+--]]
+
+module(..., package.seeall)
+
+local TreeNode = require('acf.model.field').TreeNode
+local npairs = require('acf.model.node').pairs
+local object = require('acf.object')
+
+
+local function find(set, value)
+   for i, member in npairs(set) do
+      if member == value then return i end
+   end
+end
+
+
+Set = object.class(require('acf.model.node').Collection)
+
+function Set:init(context, params)
+   assert(not object.isinstance(params.field, TreeNode))
+   object.super(self, Set):init(context, params)
+
+   local mt = getmetatable(self)
+   mt.meta.type = 'set'
+
+   function mt.__index(t, k) return find(self, k) and k end
+
+   function mt.__newindex(t, k, v)
+      assert(v == nil)
+      local i = find(self, k)
+      if not i then return end
+
+      local len = #mt.members()
+      while i < len do
+	 mt.set(i, mt.get(i + 1))
+	 i = i + 1
+      end
+      mt.set(len, nil)
+   end
+end
+
+
+function add(set, value)
+   local mt = getmetatable(set)
+   if not find(set, value) then mt.set(#mt.members() + 1, value) end
+end