add i/o to readme

readme.md

@@ -1,9 +1,10 @@
 
 # BlockLua
 ## How to Install
-- Install RedBlocklandLoader
+- Install RedBlocklandLoader  
-- Copy `BlockLua.dll` and `lua5.1.dll` into the `modules` folder next to `Blockland.exe`
+- Copy `lua5.1.dll` into your Blockland install folder, next to `Blockland.exe`  
-- Optional: Copy the `lualib` folder into `modules`
+- Copy `BlockLua.dll` into the `modules` folder within the Blockland folder  
+- Optional: Copy the `lualib` folder into `modules`  
 
 
 ## Quick Reference
@@ -36,9 +37,9 @@
 ### Advanced
 `sched = bl.schedule(timeMs, function, args...)` - Schedule a Lua function to be called later, similar to schedule in Torque  
 `sched:cancel()` - Cancel a previously scheduled timer  
-`hitObject, hisPos, hitNormal = bl.raycast(vector{startPosX,y,z}, vector{endPosX,y,z}, 'typeMask'/{'typeMasks',...}, ignoreObject...?)` - Cast a ray in the world over objects of the specified type(s) (possibly excluding some objects), and return the object hit, the position of the hit, and the normal vector to the surface hit.
+`hitObject, hisPos, hitNormal = bl.raycast(vector{startPosX,y,z}, vector{endPosX,y,z}, 'objtype'/{'objtypes',...}, ignoreObjects...?)` - Cast a ray in the world over objects of the specified type(s) (possibly excluding some objects), and return the object hit, the position of the hit, and the normal vector to the surface hit. See the Types section for a list of valid object types.
-`for object in bl.boxSearch(vector{centerX,y,z}, vector{sizeX,y,z}, 'typeMask'/{'typeMasks',...}) do` - Find all objects in the world of the specified type(s) whose bounding box overlaps with a specific box  
+`for object in bl.boxSearch(vector{centerX,y,z}, vector{sizeX,y,z}, 'objtype'/{'objtypes',...}) do` - Find all objects in the world of the specified type(s) whose bounding box overlaps with the specified box. See the Types section for a list of valid object types.  
-`for object in bl.radiusSearch(vector{centerX,y,z}, radius, 'typeMask'/{'typeMasks',...}) do` - Find all objects of the specified type(s) whose bounding box overlaps with a specified sphere  
+`for object in bl.radiusSearch(vector{centerX,y,z}, radius, 'objtype'/{'objtypes',...}) do` - Find all objects of the specified type(s) whose bounding box overlaps with the specified sphere. See the Types section for a list of valid object types.  
 `bl.serverCmd('commandName', function(client, args...) code() end)` - Register a /-command on the server  
 `bl.clientCmd('commandName', function(args...) code() end)` - Register a client command on the client  
 
@@ -55,9 +56,31 @@
 `bl.class('className')` - Register a Torque class to be used from Lua (Already done for all built-in classes)  
 `bl.class('className', 'parentClassName')` - Same as above, with inheritance  
 
+### File I/O
+Lua's builtin file I/O is emulated, and is confined to the same directories as TorqueScript file I/O.  
+Relative paths (`./`) are allowed. `..` is not allowed.  
+`file = io.open('./file.txt', 'r'/'w'/'a'/'rb'/'wb'/'ab')` - Open a file  
+`file:read(numberOfChars/'*a')` - Read an opened file (must be opened in 'r' (read) or 'rb' (read binary) mode)  
+`file:write(string)` - Write an opened file (must be opened in 'w' (write), 'a' (append), 'wb' or 'ab' mode)  
+`file:close()` - Close an opened file  
+Reading files from ZIPs is supported, with caveats. Null characters are not allowed, and \r\n becomes \n. Generally, text formats work, and binary formats don't.  
+
+### Modules and Dependencies
+`dofile('Add-Ons/Path/file.lua')` - Execute a Lua file. Relative paths (`./file.lua`) are allowed. `..` is not allowed.  
+`require('modulePath.moduleName')` - Load a Lua file or or external library.
+Require replaces `.` with `/` in the path, and then searches for files in the following order:  
+- `./modulePath/moduleName.lua`  
+- `./modulePath/moduleName/init.lua`  
+- `modulePath/moduleName.lua` (Relative to game directory)  
+- `modulePath/moduleName/init.lua` (Relative to game directory)  
+- `modules/lualib/modulePath/moduleName.lua`  
+- `modules/lualib/modulePath/moduleName/init.lua`  
+- `modules/lualib/modulePath/moduleName.dll`  
+Like in standard Lua, modules loaded using `require` are only executed the first time `require` is called with that path. Subsequent calls simply return the result from the initial execution. To allow hot reloading, use `dofile`.
+
 ## Type Conversion
 When a TorqueScript function is called from Lua or vice-versa, the arguments and return value must be converted between the two languages' type systems.  
-TorqueScript has no type information; all values in TorqueScript are strings. So, it's necessary to make some inferences when converting values between the two languages.  
+TorqueScript stores no type information; all values in TorqueScript are strings. So it's necessary to make some inferences when converting values between the two languages.  
 ### From TorqueScript to Lua
 - Any numeric value becomes a Lua `number`, except as specified with `ts.type`, which may convert a value into a `boolean` or a Torque object container.  
 - The empty string "" becomes `nil`  
@@ -73,5 +96,21 @@ TorqueScript has no type information; all values in TorqueScript are strings. So
 - Any `string` is passed directly as a string  
 - Tables cannot be passed and will throw an error  
 
-## Unsafe Mode
+## I/O and Safety
+All Lua code is sandboxed, and file access is confied to the default directories in the same way TorqueScript is.  
+BlockLua also has access to any C libraries installed in the `modules/lualib` folder, so be careful throwing things in there.  
+### Unsafe Mode
 BlockLua-Unsafe.dll can be used in place of BlockLua.dll, to remove the sandboxing of Lua code. This allows Lua code to access any file and use any library, including ffi.  
+Please do not publish add-ons that require unsafe mode.  
+
+## Other Reference
+
+### List of Object Types
+'all' - Any object  
+'brick' - Bricks with Ray-Casting enabled  
+'brickalways' - All bricks including those with Ray-Casting disabled  
+'player' - Players or bots  
+'item' - Items  
+'vehicle' - Vehicles  
+'projectile' - Projectiles  
+Other types: 'static', 'environment', 'terrain', 'water', 'trigger', 'marker', 'gamebase', 'shapebase', 'camera', 'staticshape', 'vehicleblocker', 'explosion', 'corpse', 'debris', 'physicalzone', 'staticts', 'staticrendered', 'damagableitem'

src/util/libts.lua

@@ -166,7 +166,9 @@ local function file_exists(fn, errn)
 		return nil
 	end
 end
+local require_memo = {}
 function require(mod)
+	if require_memo[mod] then return unpack(require_memo[mod]) end
 	local fp = mod:gsub('%.', '/')
 	local fns = {
 		'./'..fp..'.lua',      -- local file
@@ -182,7 +184,9 @@ function require(mod)
 	for _,fn in ipairs(fns) do
 		local fne = file_exists(fn, 2)
 		if fne then
-			return dofile(fne, 2)
+			local res = {dofile(fne, 2)}
+			require_memo[mod] = res
+			return unpack(res)
 		end
 	end
 	return _bllua_requiresecure(mod)