--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/share/lua/5.2/luarocks/manif_core.lua	Fri Dec 14 22:24:27 2012 +0000
@@ -0,0 +1,79 @@
+
+--- Core functions for querying manifest files.
+-- This module requires no specific 'fs' functionality.
+module("luarocks.manif_core", package.seeall)
+
+local persist = require("luarocks.persist")
+local type_check = require("luarocks.type_check")
+local dir = require("luarocks.dir")
+local util = require("luarocks.util")
+local cfg = require("luarocks.cfg")
+local path = require("luarocks.path")
+
+manifest_cache = {}
+
+--- Back-end function that actually loads the manifest
+-- and stores it in the manifest cache.
+-- @param file string: The local filename of the manifest file.
+-- @param repo_url string: The repository identifier.
+-- @param quick boolean: If given, skips type checking.
+function manifest_loader(file, repo_url, quick)
+   local manifest, err = persist.load_into_table(file)
+   if not manifest then
+      return nil, "Failed loading manifest for "..repo_url..": "..err
+   end
+   if not quick then
+      local ok, err = type_check.type_check_manifest(manifest)
+      if not ok then
+         return nil, "Error checking manifest: "..err
+      end
+   end
+
+   manifest_cache[repo_url] = manifest
+   return manifest
+end
+
+--- Load a local manifest describing a repository.
+-- All functions that use manifest tables assume they were obtained
+-- through either this function or load_manifest.
+-- @param repo_url string: URL or pathname for the repository.
+-- @return table or (nil, string): A table representing the manifest,
+-- or nil followed by an error message.
+function load_local_manifest(repo_url)
+   assert(type(repo_url) == "string")
+
+   if manifest_cache[repo_url] then
+      return manifest_cache[repo_url]
+   end
+
+   local pathname = dir.path(repo_url, "manifest")
+
+   return manifest_loader(pathname, repo_url, true)
+end
+
+--- Get all versions of a package listed in a manifest file.
+-- @param name string: a package name.
+-- @param deps_mode string: "one", to use only the currently
+-- configured tree; "order" to select trees based on order
+-- (use the current tree and all trees below it on the list)
+-- or "all", to use all trees.
+-- @return table: An array of strings listing installed
+-- versions of a package.
+function get_versions(name, deps_mode)
+   assert(type(name) == "string")
+   assert(type(deps_mode) == "string")
+   
+   local manifest = {}
+   path.map_trees(deps_mode, function(tree)
+      local loaded = load_local_manifest(path.rocks_dir(tree))
+      if loaded then
+         util.deep_merge(manifest, loaded)
+      end
+   end)
+   
+   local item = next(manifest) and manifest.repository[name]
+   if item then
+      return util.keys(item)
+   end
+   return {}
+end