Mercurial > repos > lgen / file diff

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ltp/util.lua	Sun Sep 13 22:22:47 2009 +0300
@@ -0,0 +1,100 @@
+--
+-- Copyright 2007-2008 Savarese Software Research Corporation.
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--     http://www.savarese.com/software/ApacheLicense-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+--
+
+local function slice(t, start, size)
+  local sz = (size or (#t - start + 1))
+  local result = { }
+
+  for i = 1, sz, 1 do
+    result[i] = t[start + i - 1]
+  end
+
+  return result
+end
+
+local function dual_index(index1, index2)
+  local index1_type = type(index1)
+
+  if index1_type == "table" then
+    return function(t,k)
+             if index1[k] ~= nil then
+               return index1[k]
+             else
+               return index2[k]
+             end
+           end
+  elseif index1_type == "function" then
+    return function(t,k)
+             local v = index1(t,k)
+             if v ~= nil then
+               return v
+             else
+               return index2[k]
+             end
+           end
+  end
+end
+
+local function merge_index(t1, t2)
+  local mt = getmetatable(t1)
+
+  if mt ~= nil then
+    if mt.__index ~= nil then
+      mt.__index = dual_index(mt.__index, t2)
+    else
+      mt.__index = t2
+    end
+    return t1
+  else
+    return setmetatable(t1, {__index = t2})
+  end
+end
+
+local function merge_table(t1, t2)
+  local typet1
+
+  for k, v in pairs(t2) do
+    typet1 = type(t1[k])
+    if t1[k] ~= v and type(v) == "table" then
+      if typet1 == "table" then
+        merge_table(t1[k], v)
+      elseif typet1 == "nil" then
+        t1[k] = v
+      end
+    end
+  end
+
+  return merge_index(t1, t2)
+end
+
+local function import(module_name, environment)
+  return setfenv(package.loaders[2](module_name), environment)()
+end
+
+local function read_all(filename)
+  local file = io.open(filename, "r")
+  local data = ((file and file:read("*a")) or nil)
+  if file then
+    file:close()
+  end
+  return data
+end
+
+return { slice = slice,
+         merge_index = merge_index,
+         merge_table = merge_table,
+         import = import,
+         read_all = read_all }