CLOD: Simple list methods with simple algorithm for replacement strategy

2 files changed, 101 insertions, 0 deletions

diff --git a/lib/clod.lua b/lib/clod.lua
index 7696d5e..4114fd6 100644
--- a/lib/clod.lua
+++ b/lib/clod.lua
@@ -177,6 +177,16 @@ function settings_mt:__newindex(subkey, value)
 	 if last.key then
 	    insert_blank = true
 	 end
+      else
+	 -- Starting at longest_prefix_found_at, iterate
+	 -- until it no longer matches the prefix
+	 local entry = longest_prefix_found_at
+	 while entry.next and (entry.next.key and
+			       (entry.next.key:sub(1, longest_prefix) ==
+				longest_prefix_found_at.key:sub(1, longest_prefix))) do
+	    entry = entry.next
+	 end
+	 longest_prefix_found_at = entry
       end
       local before = longest_prefix_found_at
       if insert_blank then
@@ -242,6 +252,38 @@ function methods:each(prefix)
    return iterator, metadata[self], nil
 end
 
+function methods:get_list(prefix)
+   local ret = {}
+   local map = {}
+   for k, v in self:each(prefix) do
+      ret[#ret+1] = k
+      map[k] = v
+   end
+   table.sort(ret)
+   for i = 1, #ret do
+      ret[i] = map[ret[i]]
+   end
+   return ret
+end
+
+function methods:set_list(prefix, list)
+   -- This algorithm isn't perfect, but it'll do in the face of
+   -- lazy apps devs who don't look after keys/value pairs themselves
+   local old_list = self:get_list(prefix)
+   -- Step one is to update all extant entries
+   for i = 1, #list do
+      local key = ("%s.i_%d"):format(prefix, i)
+      self.settings[key] = list[i]
+   end
+   -- If the new list is shorter, delete trailing entries
+   if #list < #old_list then
+      for i = #list + 1, #old_list do
+      local key = ("%s.i_%d"):format(prefix, i)
+      self.settings[key] = nil
+      end
+   end
+end
+
 -- Metamethods for clod instances
 function clod_mt:__index(key)
    if key == "settings" then
diff --git a/test/test-clod.lua b/test/test-clod.lua
index f8baa77..7fc05cd 100644
--- a/test/test-clod.lua
+++ b/test/test-clod.lua
@@ -256,6 +256,65 @@ owner.name "Daniel"
    assert(not had_owner)
 end
 
+function suite.get_list()
+   local input_str = [[
+foo["*"] "Hello"
+foo["*"] "World"
+]]
+   local conf = clod.parse(input_str)
+   local list = conf:get_list('foo')
+   assert(#list == 2)
+   assert(list[1] == "Hello")
+   assert(list[2] == "World")
+end
+
+function suite.set_list_same_length()
+   local input_str = [[
+foo["*"] "Hello"
+foo["*"] "World"
+]]
+   local conf = clod.parse(input_str)
+   local list = { "Yeesh", "Gawd" }
+   conf:set_list("foo", list)
+   local output_str = [[
+foo["*"] "Yeesh"
+foo["*"] "Gawd"
+]]
+   assert(conf:serialise() == output_str)
+end
+
+function suite.set_list_longer_length()
+   local input_str = [[
+foo["*"] "Hello"
+foo["*"] "World"
+]]
+   local conf = clod.parse(input_str)
+   local list = { "Yeesh", "Gawd", "Cripes" }
+   conf:set_list("foo", list)
+   local output_str = [[
+foo["*"] "Yeesh"
+foo["*"] "Gawd"
+foo["*"] "Cripes"
+]]
+   assert(conf:serialise() == output_str)
+end
+
+function suite.set_list_shorter_length()
+   local input_str = [[
+foo["*"] "Hello"
+foo["*"] "World"
+foo["*"] "Badger"
+]]
+   local conf = clod.parse(input_str)
+   local list = { "Yeesh", "Gawd" }
+   conf:set_list("foo", list)
+   local output_str = [[
+foo["*"] "Yeesh"
+foo["*"] "Gawd"
+]]
+   assert(conf:serialise() == output_str)
+end
+
 local count_ok = 0
 for _, testname in ipairs(testnames) do
 --   print("Run: " .. testname)