loadmaps.lua auto-loads .des files in dat.

4 files changed, 45 insertions, 36 deletions

diff --git a/crawl-ref/source/dat/clua/loadmaps.lua b/crawl-ref/source/dat/clua/loadmaps.lua
index 663005d333..35580cd56f 100644
--- a/crawl-ref/source/dat/clua/loadmaps.lua
+++ b/crawl-ref/source/dat/clua/loadmaps.lua
@@ -1,31 +1,10 @@
 ------------------------------------------------------------------------------
 -- loadmaps.lua:
 --
--- Compiles and loads .des files that Crawl needs. This only includes the
--- base .des files. Optional .des files that the user requests in .crawlrc
--- are handled separately.
+-- Compiles and loads .des files that Crawl needs.
 ------------------------------------------------------------------------------
 
-local des_files = {
-  -- The dummy vaults that define global vault generation odds.
-  "dummy.des",
-
-  -- Example vaults, included here so that Crawl will syntax-check them.
-  "didact.des",
-
-  "arena.des",
-
-  "layout.des", "rooms.des",
-
-  -- Portal vaults.
-  "bazaar.des", "bailey.des", "icecave.des", "lab.des", "ossuary.des",
-  "sewer.des", "trove.des", "shrine.des", "volcano.des", "ziggurat.des",
-
-  -- Normal vaults.
-  "altar.des", "entry.des", "elf.des", "float.des", "hells.des", "hive.des",
-  "lair.des", "large.des", "mini.des", "orc.des", "pan.des", "shoals.des",
-  "temple.des", "vaults.des", "crypt.des", "zot.des"
-}
+local des_files = file.datadir_files("dat", ".des")
 
 for _, file in ipairs(des_files) do
    dgn.load_des_file(file)
diff --git a/crawl-ref/source/files.cc b/crawl-ref/source/files.cc
index cb92d19843..30c4fa6e8f 100644
--- a/crawl-ref/source/files.cc
+++ b/crawl-ref/source/files.cc
@@ -503,11 +503,12 @@ std::string canonicalise_file_separator(const std::string &path)
 
 std::string datafile_path(std::string basename,
                           bool croak_on_fail,
-                          bool test_base_path)
+                          bool test_base_path,
+                          bool (*thing_exists)(const std::string&))
 {
     basename = canonicalise_file_separator(basename);
 
-    if (test_base_path && file_exists(basename))
+    if (test_base_path && thing_exists(basename))
         return (basename);
 
     const std::string rawbases[] = {
@@ -562,7 +563,7 @@ std::string datafile_path(std::string basename,
         for (unsigned p = 0; p < sizeof(prefixes) / sizeof(*prefixes); ++p)
         {
             std::string name = bases[b] + prefixes[p] + basename;
-            if (file_exists(name))
+            if (thing_exists(name))
                 return (name);
         }
 
diff --git a/crawl-ref/source/files.h b/crawl-ref/source/files.h
index 80dcf2c3ec..5c639eeb14 100644
--- a/crawl-ref/source/files.h
+++ b/crawl-ref/source/files.h
@@ -41,9 +41,12 @@ std::vector<std::string> get_dir_files(const std::string &dir);
 std::vector<std::string> get_dir_files_ext(const std::string &dir,
                                            const std::string &ext);
 
-std::string datafile_path(std::string basename,
-                          bool croak_on_fail = true,
-                          bool test_base_path = false);
+std::string datafile_path(
+    std::string basename,
+    bool croak_on_fail = true,
+    bool test_base_path = false,
+    bool (*thing_exists)(const std::string&) = file_exists);
+
 
 bool get_dos_compatible_file_name(std::string *fname);
 std::string get_parent_directory(const std::string &filename);
diff --git a/crawl-ref/source/l_file.cc b/crawl-ref/source/l_file.cc
index e619327cbe..bde31cb558 100644
--- a/crawl-ref/source/l_file.cc
+++ b/crawl-ref/source/l_file.cc
@@ -1,8 +1,10 @@
 #include "AppHdr.h"
 
 #include "clua.h"
+#include "cluautil.h"
 #include "dlua.h"
 #include "l_libs.h"
+#include "files.h"
 
 #include "tags.h"
 
@@ -144,15 +146,39 @@ static int file_unmarshall_meta(lua_State *ls)
     return (0);
 }
 
+// Returns a Lua table of filenames in the named directory. The file names
+// returned are unqualified. The directory must be a relative path, and will
+// be resolved to an absolute path if necessary using datafile_path.
+LUAFN(_file_datadir_files)
+{
+    const std::string rawdir(luaL_checkstring(ls, 1));
+    // A filename suffix to match (such as ".des"). If empty, files
+    // will be unfiltered.
+    const std::string ext_filter(lua_isnoneornil(ls, 2) ? "" :
+                                 luaL_checkstring(ls, 2));
+    const std::string datadir(
+        datafile_path(rawdir, false, false, dir_exists));
+
+    if (datadir.empty())
+        luaL_error(ls, "Cannot find data directory: '%s'", rawdir.c_str());
+
+    const std::vector<std::string> files =
+        ext_filter.empty() ? get_dir_files(datadir) :
+        get_dir_files_ext(datadir, ext_filter);
+    return clua_stringtable(ls, files);
+}
+
 static const struct luaL_reg file_dlib[] =
 {
-{ "marshall",   file_marshall },
-{ "marshall_meta", file_marshall_meta },
-{ "unmarshall_meta", file_unmarshall_meta },
-{ "unmarshall_number", file_unmarshall_number },
-{ "unmarshall_string", file_unmarshall_string },
-{ "unmarshall_fn", file_unmarshall_fn },
-{ NULL, NULL }
+    { "marshall",   file_marshall },
+    { "marshall_meta", file_marshall_meta },
+    { "unmarshall_meta", file_unmarshall_meta },
+    { "unmarshall_number", file_unmarshall_number },
+    { "unmarshall_string", file_unmarshall_string },
+    { "unmarshall_fn", file_unmarshall_fn },
+
+    { "datadir_files", _file_datadir_files },
+    { NULL, NULL }
 };
 
 void dluaopen_file(lua_State *ls)