Allow Lua scripts to be used as modules.

Lua API.rst

@@ -3399,6 +3399,19 @@ from other scripts) in any context, via the same function the core uses:
 
 Note that this function lets errors propagate to the caller.
 
+* ``dfhack.script_environment(name)``
+
+  Run an Lua script and return its environment.
+  This command allows you to use scripts like modules for increased portability.
+  It is highly recommended that if you are a modder you put your custom modules in ``raw/scripts`` and use ``script_environment`` instead of ``require`` so that saves with your mod installed will be self-contained and can be transferred to people who do have DFHack but do not have your mod installed.
+  You can say ``dfhack.script_environment('add-thought').addEmotionToUnit([arguments go here])`` and it will have the desired effect.
+  It will call the script in question with the global ``moduleMode`` set to ``true`` so that the script can return early.
+  This is useful because if the script is called from the console it should deal with its console arguments and if it is called by ``script_environment`` it should only create its global functions and return.
+  You can also access global variables with, for example ``print(dfhack.script_environment('add-thought').validArgs)``
+  The function ``script_environment`` is fast enough that it is recommended that you not store its result in a nonlocal variable, because your script might need to load a different version of that script if the save is unloaded and a save with a different mod that overrides the same script with a slightly different functionality is loaded.
+  This will not be an issue in most cases.
+  This function also permits circular dependencies of scripts.
+
 Save init script
 ================
 

NEWS

@@ -1,6 +1,7 @@
 DFHack Future
     Internals
         Lua scripts can set environment variables of each other with dfhack.run_script_with_env.
+        Lua scripts can now call each others internal nonlocal functions with dfhack.script_environment(scriptName).functionName(arg1,arg2).
         eventful Lua reactions no longer require LUA_HOOK as a prefix: you can register a callback for the completion of any reaction with a name
         Filesystem module now provides file access/modification times and can list directories (normally and recursively)
         Units Module: New functions:

library/lua/dfhack.lua

@@ -385,7 +385,7 @@ internal.scripts = internal.scripts or {}
 local scripts = internal.scripts
 local hack_path = dfhack.getHackPath()
 
-local function findScript(name)
+function dfhack.findScript(name)
     local file
     file = dfhack.getSavePath()
     if file then
@@ -410,8 +410,13 @@ function dfhack.run_script(name,...)
     return dfhack.run_script_with_env(nil,name,...)
 end
 
+function dfhack.script_environment(name)
+    _, env = dfhack.run_script_with_env({moduleMode=true}, name)
+    return env
+end
+
 function dfhack.run_script_with_env(envVars,name,...)
-    local file = findScript(name)
+    local file = dfhack.findScript(name)
     if not file then
         error('Could not find script ' .. name)
     end

scripts/add-thought.lua

@@ -2,7 +2,7 @@
 
 local utils=require('utils')
 
-local function addEmotionToUnit(unit,thought,emotion,severity,strength,subthought)
+function addEmotionToUnit(unit,thought,emotion,severity,strength,subthought)
     local emotions=unit.status.current_soul.personality.emotions
     if not (type(emotion)=='number') then emotion=df.emotion_type[emotion] end
     if not (type(thought)=='number') then thought=df.unit_thought_type[thought] end
@@ -41,6 +41,10 @@ function tablify(iterableObject)
     return t
 end
 
+if moduleMode then
+ return
+end
+
 local args = utils.processArgs({...}, validArgs)
 
 local unit = args.unit and df.unit.find(args.unit) or dfhack.gui.getSelectedUnit(true)