CLOD: Add rudimentary list support so we can convert Gitano's group configs

3 files changed, 169 insertions, 3 deletions

diff --git a/examples/configuration-lists.lua b/examples/configuration-lists.lua
new file mode 100644
index 0000000..cfecc91
--- /dev/null
+++ b/examples/configuration-lists.lua
@@ -0,0 +1,45 @@
+-- examples/configuration-lists.lua
+--
+-- Demonstrate lists in clod configurations
+--
+-- Copyright 2012 Daniel Silverstone <dsilvers@digital-scurf.org>
+--
+
+clod = require "clod"
+
+-- Clod's list support is a side-effect of its dictionary-like syntax
+-- Essentially lists are not supported.  In practice, Clod simulates
+-- them by the ability to iterate subsets of the configuration.
+-- You cannot usefully reorder lists, they're just dictionaries with
+-- automatic keys.  When Clod saves configurations, it changes trailing
+-- i_[0-9]+ keys into a ["*"].  This is a tad 'magical' but never mind.
+
+local configuration = [[
+group.members["*"] "dsilvers"
+group.members["*"] "liw"
+
+wont.see.this "ERROR"
+
+group.members["*"] "rjek"
+group.members["*"] "robtaylor"
+]]
+
+conf, err = clod.parse(configuration)
+if not conf then
+   error(err)
+end
+
+print("Input config:")
+io.stdout:write(configuration)
+print()
+print()
+
+print("Group members in the conf (by conf:each('group.members') iterator):")
+for key, value in conf:each("group.members") do
+   print(key, value)
+end
+print()
+print()
+
+print("Serialised output:")
+io.stdout:write(conf:serialise())
\ No newline at end of file
diff --git a/lib/clod.lua b/lib/clod.lua
index b1e5ccd..7696d5e 100644
--- a/lib/clod.lua
+++ b/lib/clod.lua
@@ -84,6 +84,20 @@ local function delete_entry(entry)
    end
 end
 
+local function has_key(confmeta, key)
+   return confmeta.settings[key] ~= nil
+end
+
+local function calculate_wild_key(confmeta, prefix)
+   local keyno = 1
+   local keystr = ("%si_%s"):format(prefix, keyno)
+   while has_key(confmeta, keystr) do
+      keyno = keyno + 1
+      keystr = ("%si_%s"):format(prefix, keyno)
+   end
+   return keystr
+end
+
 function settings_mt:__newindex(subkey, value)
    local meta = metadata[self]
    local confmeta = metadata[meta.conf]
@@ -94,6 +108,11 @@ function settings_mt:__newindex(subkey, value)
    if meta.prefix then
       key = meta.prefix .. "." .. subkey
    end
+   local wild_prefix, last_key_element = key:match("^(.-)([^.]+)$")
+   if last_key_element == "*" then
+      -- Wild insert, so calculate a unique key to use
+      key = calculate_wild_key(confmeta, wild_prefix)
+   end
    if value == nil then
       -- removing an entry...
       if confmeta.settings[key] then
@@ -178,6 +197,10 @@ function methods:serialise()
    local function serialise_entry(entry)
       local key, value, line = entry.key, entry.value, ""
       if key then
+	 local wild_prefix = key:match("^(.-)%.i_[0-9]+$")
+	 if wild_prefix then
+	    key = wild_prefix .. '["*"]'
+	 end
 	 local vtype = type(value)
 	 assert((vtype == "string" or vtype == "number" or vtype == "boolean"),
 		"Unexpected " .. vtype .. " in key: " .. key)
@@ -201,6 +224,24 @@ function methods:serialise()
    return tconcat(retstr, "\n")
 end
 
+function methods:each(prefix)
+   if prefix then
+      prefix = "^" .. prefix:gsub("%.", "%%.")
+   end
+   local function iterator(confmeta, prev_key)
+      local next_key, next_value = next(confmeta.settings, prev_key)
+      if prefix then
+	 while next_key and not next_key:match(prefix) do
+	    next_key, next_value = next(confmeta.settings, next_key)
+	 end
+      end
+      if next_key and next_value then
+	 return next_key, next_value.value
+      end
+   end
+   return iterator, metadata[self], nil
+end
+
 -- Metamethods for clod instances
 function clod_mt:__index(key)
    if key == "settings" then
@@ -236,14 +277,19 @@ local function parse_config(conf, confname)
       if type(value) == "table" or type(value) == "function" then
 	 error("Clod does not support " .. type(value) .. "s as values")
       end
-      return self[key](value)
+      return self[key](value, 1)
    end
-   function parse_mt:__call(value)
+   function parse_mt:__call(value, offset)
       if type(value) == "table" or type(value) == "function" then
 	 error("Clod does not support " .. type(value) .. "s as values")
       end
       local key = assert(keys[self])
-      local curline = getinfo(2, "Snlf").currentline
+      local wild_prefix, last_key_element = key:match("^(.-)([^.]+)$")
+      if last_key_element == "*" then
+	 -- Wild insert, so calculate a unique key to use
+	 key = calculate_wild_key({settings=settings}, wild_prefix)
+      end
+      local curline = getinfo(2 + (offset or 0), "Snlf").currentline
       local entry = { key = key, value = value, lineno = curline }
       while last_entry.lineno < (curline - 1) do
 	 local empty = { 
diff --git a/test/test-clod.lua b/test/test-clod.lua
index d64587c..f8baa77 100644
--- a/test/test-clod.lua
+++ b/test/test-clod.lua
@@ -181,6 +181,81 @@ function suite.insert_into_blank_two_similar_one_dissimilar_variant()
    assert(conf:serialise() == 'person.name "Lars"\nperson.age = 42\n\npants.style "Y-Front"\n')
 end
 
+function suite.parse_wild_key()
+   local conf = assert(clod.parse('foo["*"] "bar"'))
+   assert(conf.settings.foo.i_1 == "bar")
+end
+
+function suite.insert_wild_key()
+   local conf = assert(clod.parse(""))
+   conf.settings["foo.*"] = "bar"
+   assert(conf.settings.foo.i_1 == "bar")
+end
+
+function suite.insert_two_wild_keys()
+   local conf = assert(clod.parse(""))
+   conf.settings["foo.*"] = "bar"
+   conf.settings["foo.*"] = "baz"
+   assert(conf.settings.foo.i_1 == "bar")
+   assert(conf.settings.foo.i_2 == "baz")
+end
+
+function suite.serialise_wild_keys()
+   local input_str = 'foo["*"] "bar"\n'
+   local conf = assert(clod.parse(input_str))
+   assert(conf:serialise() == input_str)
+end
+
+function suite.iterate_all()
+   local input_str = [[
+project.name "Clod"
+project.description "Badgering stoats"
+
+owner.name "Daniel"
+]]
+   local conf = assert(clod.parse(input_str))
+   local had_name, had_desc, had_owner
+   for k, v in conf:each() do
+      if k == "project.name" then
+	 had_name = true
+      elseif k == "project.description" then
+	 had_desc = true
+      elseif k == "owner.name" then
+	 had_owner = true
+      else
+	 assert(false)
+      end
+   end
+   assert(had_name)
+   assert(had_desc)
+   assert(had_owner)
+end
+
+function suite.iterate_subset()
+   local input_str = [[
+project.name "Clod"
+project.description "Badgering stoats"
+
+owner.name "Daniel"
+]]
+   local conf = assert(clod.parse(input_str))
+   local had_name, had_desc, had_owner
+   for k, v in conf:each("project") do
+      if k == "project.name" then
+	 had_name = true
+      elseif k == "project.description" then
+	 had_desc = true
+      elseif k == "owner.name" then
+	 had_owner = true
+      else
+	 assert(false)
+      end
+   end
+   assert(had_name)
+   assert(had_desc)
+   assert(not had_owner)
+end
+
 local count_ok = 0
 for _, testname in ipairs(testnames) do
 --   print("Run: " .. testname)