jvmAndroidMain.org.luaj.vm2.lib.jse.JseBaseLib.kt Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2009 Luaj.org. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package org.luaj.vm2.lib.jse
import java.io.File
import java.io.FileInputStream
import java.io.IOException
import java.io.InputStream
import org.luaj.vm2.Globals
import org.luaj.vm2.LuaValue
import org.luaj.vm2.io.*
import org.luaj.vm2.lib.BaseLib
import org.luaj.vm2.lib.LibFunction
import org.luaj.vm2.lib.ResourceFinder
/**
* Subclass of [BaseLib] and [LibFunction] which implements the lua basic library functions
* and provides a directory based [ResourceFinder] as the [Globals.finder].
*
*
* Since JME has no file system by default, [BaseLib] implements
* [ResourceFinder] using [Class.getResource].
* The [JseBaseLib] implements [Globals.finder] by scanning the current directory
* first, then falling back to [Class.getResource] if that fails.
* Otherwise, the behavior is the same as that of [BaseLib].
*
*
* Typically, this library is included as part of a call to
* [org.luaj.vm2.lib.jse.JsePlatform.standardGlobals]
* `Globals globals = JsePlatform.standardGlobals();
* globals.get("print").call(LuaValue.valueOf("hello, world"));
` *
*
*
* For special cases where the smallest possible footprint is desired,
* a minimal set of libraries could be loaded
* directly via [Globals.load] using code such as:
* `Globals globals = new Globals();
* globals.load(new JseBaseLib());
* globals.get("print").call(LuaValue.valueOf("hello, world"));
` *
*
* However, other libraries such as *PackageLib* are not loaded in this case.
*
*
* This is a direct port of the corresponding library in C.
* @see Globals
*
* @see BaseLib
*
* @see ResourceFinder
*
* @see Globals.finder
*
* @see LibFunction
*
* @see org.luaj.vm2.lib.jse.JsePlatform
*
* @see org.luaj.vm2.lib.jme.JmePlatform
*
* @see [Lua 5.2 Base Lib Reference](http://www.lua.org/manual/5.2/manual.html.6.1)
*/
class JseBaseLib : BaseLib() {
/** Perform one-time initialization on the library by creating a table
* containing the library functions, adding that table to the supplied environment,
* adding the table to package.loaded, and returning table as the return value.
* Specifically, extend the library loading to set the default value for [Globals.STDIN]
* @param modname the module name supplied if this is loaded via 'require'.
* @param env the environment to load into, which must be a Globals instance.
*/
override fun call(modname: LuaValue, env: LuaValue): LuaValue {
super.call(modname, env)
env.checkglobals()!!.STDIN = System.`in`.toLua()
return env
}
/**
* Try to open a file in the current working directory,
* or fall back to base opener if not found.
*
* This implementation attempts to open the file using new File(filename).
* It falls back to the base implementation that looks it up as a resource
* in the class path if not found as a plain file.
*
* @see BaseLib
*
* @see ResourceFinder
*
*
* @param filename
* @return InputStream, or null if not found.
*/
override fun findResource(filename: String): LuaBinInput? {
val f = File(filename)
if (!f.exists())
return super.findResource(filename)
try {
return f.readBytes().toLuaBinInput()
} catch (ioe: IOException) {
return null
}
}
}