1 files changed, 74 insertions, 0 deletions
diff --git a/crawl-ref/source/lua/base.lua b/crawl-ref/source/lua/base.lua
new file mode 100644
index 0000000000..db7b15afda
--- /dev/null
+++ b/crawl-ref/source/lua/base.lua
@@ -0,0 +1,74 @@
+---------------------------------------------------------------------------
+-- base.lua:
+-- Base Lua definitions that other Lua scripts rely on.
+-- NOTE: Other Lua scripts may demonstrate buggy behaviour if you do
+--       not source this file. If you're using no Lua scripts at all, you
+--       needn't source base.lua.
+--
+-- To use this, add this line to your init.txt:
+--   lua_file = lua/base.lua
+---------------------------------------------------------------------------
+
+-- Lua global data
+chk_interrupt_macro     = { }
+chk_interrupt_activity  = { }
+chk_lua_option          = { }
+
+-- Push into this table, rather than indexing into it.
+chk_lua_save            = { }
+
+function c_save(file)
+    if not chk_lua_save then
+        return
+    end
+    
+    for i, fn in ipairs(chk_lua_save) do
+        fn(file)
+    end    
+end
+
+-- This function returns true to tell Crawl not to process the option further
+function c_process_lua_option(key, val)
+    if chk_lua_option and chk_lua_option[key] then
+        return chk_lua_option[key](key, val)
+    end
+    return false
+end
+
+function c_interrupt_macro(iname, cause, extra)
+    -- If some joker undefined the table, stop all macros
+    if not chk_interrupt_macro then
+        return true
+    end
+
+    -- Maybe we don't know what macro is running? Kill it to be safe
+    -- We also kill macros that don't add an entry to chk_interrupt_macro.
+    if not c_macro_name or not chk_interrupt_macro[c_macro_name] then
+        return true
+    end
+
+    return chk_interrupt_macro[c_macro_name](iname, cause, extra)
+end
+
+-- Notice that c_interrupt_activity defaults to *false* whereas 
+-- c_interrupt_macro defaults to *true*. This is because "false" really just
+-- means "go ahead and use the default logic to kill this activity" here, 
+-- whereas false is interpreted as "no, don't stop this macro" for 
+-- c_interrupt_macro.
+--
+-- If c_interrupt_activity, or one of the individual hooks wants to ensure that
+-- the activity continues, it must return *nil* (make sure you know what you're
+-- doing when you return nil!).
+function c_interrupt_activity(aname, iname, cause, extra)
+    -- If some joker undefined the table, bail out
+    if not chk_interrupt_activity then
+        return false
+    end
+
+    -- No activity name? Bail!
+    if not aname or not chk_interrupt_activity[aname] then
+        return false
+    end
+
+    return chk_interrupt_activity[aname](iname, cause, extra)
+end