org.luaj.vm2
Class LuaClosure

java.lang.Object
  org.luaj.vm2.Varargs
      org.luaj.vm2.LuaValue
          org.luaj.vm2.LuaFunction
              org.luaj.vm2.LuaClosure

public class LuaClosure
extends LuaFunction

Extension of LuaFunction which executes lua bytecode.

A LuaClosure is a combination of a Prototype and a LuaValue to use as an environment for execution. Normally the LuaValue is a Globals in which case the environment will contain standard lua libraries.

There are three main ways LuaClosure instances are created:

• Construct an instance using LuaClosure(Prototype, LuaValue)
• Construct it indirectly by loading a chunk via Globals.load(java.io.Reader, String)
• Execute the lua bytecode Lua.OP_CLOSURE as part of bytecode processing

To construct it directly, the Prototype is typically created via a compiler such as LuaC:

 String script = "print( 'hello, world' )";
 InputStream is = new ByteArrayInputStream(script.getBytes());
 Prototype p = LuaC.instance.compile(is, "script");
 LuaValue globals = JsePlatform.standardGlobals();
 LuaClosure f = new LuaClosure(p, globals);
 f.call();
 

To construct it indirectly, the Globals.load(java.io.Reader, String) method may be used:

 Globals globals = JsePlatform.standardGlobals();
 LuaFunction f = globals.load(new StringReader(script), "script");
 LuaClosure c = f.checkclosure();  // This may fail if LuaJC is installed.
 c.call();
 

In this example, the "checkclosure()" may fail if direct lua-to-java-bytecode compiling using LuaJC is installed, because no LuaClosure is created in that case and the value returned is a LuaFunction but not a LuaClosure.

Since a LuaClosure is a LuaFunction which is a LuaValue, all the value operations can be used directly such as:

• LuaValue.call()
• LuaValue.call(LuaValue)
• LuaValue.invoke()
• LuaValue.invoke(Varargs)
• LuaValue.method(String)
• LuaValue.method(String,LuaValue)
• LuaValue.invokemethod(String)
• LuaValue.invokemethod(String,Varargs)
• ...

See Also:

LuaValue, LuaFunction, LuaValue.isclosure(), LuaValue.checkclosure(), LuaValue.optclosure(LuaClosure), LoadState, Globals.compiler

Field Summary

Prototype	p
UpValue[]	upValues

Fields inherited from class org.luaj.vm2.LuaFunction

s_metatable

Fields inherited from class org.luaj.vm2.LuaValue

ADD, CALL, CONCAT, DIV, EMPTYSTRING, ENV, EQ, FALSE, INDEX, LE, LEN, LT, METATABLE, MINUSONE, MOD, MODE, MUL, NEWINDEX, NIL, NILS, NONE, NOVALS, ONE, POW, SUB, TBOOLEAN, TFUNCTION, TINT, TLIGHTUSERDATA, TNIL, TNONE, TNUMBER, TOSTRING, TRUE, TSTRING, TTABLE, TTHREAD, TUSERDATA, TVALUE, TYPE_NAMES, UNM, ZERO

Constructor Summary

LuaClosure(Prototype p, LuaValue env)
Create a closure around a Prototype with a specific environment.

Method Summary

LuaValue	call() Call this with 0 arguments, including metatag processing, and return only the first return value.
LuaValue	call(LuaValue arg) Call this with 1 argument, including metatag processing, and return only the first return value.
LuaValue	call(LuaValue arg1, LuaValue arg2) Call this with 2 arguments, including metatag processing, and return only the first return value.
LuaValue	call(LuaValue arg1, LuaValue arg2, LuaValue arg3) Call this with 3 arguments, including metatag processing, and return only the first return value.
LuaClosure	checkclosure() Check that the value is a LuaClosure , or throw LuaError if not
protected Varargs	execute(LuaValue[] stack, Varargs varargs)
LuaValue	getmetatable() Get the metatable for this LuaValue
protected LuaValue	getUpvalue(int i)
Varargs	invoke(Varargs varargs) Call this with variable arguments, including metatag processing, and retain all return values in a Varargs.
boolean	isclosure() Check if this is a function that is a closure, meaning interprets lua bytecode for its execution
java.lang.String	name() Return a human-readable name for this function.
Varargs	onInvoke(Varargs varargs) Callback used during tail call processing to invoke the function once.
LuaClosure	optclosure(LuaClosure defval) Check that optional argument is a closure and return as LuaClosure
protected void	setUpvalue(int i, LuaValue v)
java.lang.String	tojstring() Convert to human readable String for any type.

Methods inherited from class org.luaj.vm2.LuaFunction

checkfunction, classnamestub, isfunction, optfunction, strvalue, type, typename

Methods inherited from class org.luaj.vm2.LuaValue

add, add, add, and, arg, arg1, argerror, argerror, aritherror, aritherror, arithmt, arithmtwith, assert_, buffer, call, callmt, checkboolean, checkdouble, checkglobals, checkint, checkinteger, checkjstring, checklong, checkmetatag, checknotnil, checknumber, checknumber, checkstring, checktable, checkthread, checkuserdata, checkuserdata, compareerror, compareerror, comparemt, concat, concat, concatmt, concatTo, concatTo, concatTo, div, div, div, divInto, eq_b, eq, eqmtcall, equals, error, get, get, get, gettable, gt_b, gt_b, gt_b, gt, gt, gt, gteq_b, gteq_b, gteq_b, gteq, gteq, gteq, illegal, inext, initupvalue1, invoke, invoke, invoke, invoke, invoke, invokemethod, invokemethod, invokemethod, invokemethod, invokemethod, invokemethod, isboolean, isint, isinttype, islong, isnil, isnumber, isstring, istable, isthread, isuserdata, isuserdata, isvalidkey, len, lenerror, length, listOf, listOf, load, lt_b, lt_b, lt_b, lt, lt, lt, lteq_b, lteq_b, lteq_b, lteq, lteq, lteq, metatableOf, metatag, method, method, method, method, method, method, mod, mod, mod, modFrom, mul, mul, mul, narg, neg, neq_b, neq, next, not, optboolean, optdouble, optint, optinteger, optjstring, optlong, optnumber, optstring, opttable, optthread, optuserdata, optuserdata, optvalue, or, pow, pow, pow, powWith, powWith, presize, raweq, raweq, raweq, raweq, raweq, rawget, rawget, rawget, rawlen, rawset, rawset, rawset, rawset, rawset, rawset, rawset, rawsetlist, set, set, set, set, set, set, set, setmetatable, settable, strcmp, strcmp, strongvalue, sub, sub, sub, subargs, subFrom, subFrom, tableOf, tableOf, tableOf, tableOf, tableOf, tableOf, tailcallOf, testfor_b, toboolean, tobyte, tochar, todouble, tofloat, toint, tolong, tonumber, toshort, tostring, toString, touserdata, touserdata, typerror, unimplemented, userdataOf, userdataOf, valueOf, valueOf, valueOf, valueOf, valueOf, valueOf, varargsOf, varargsOf, varargsOf, varargsOf, varargsOf, varargsOf

Methods inherited from class org.luaj.vm2.Varargs

argcheck, checkboolean, checkclosure, checkdouble, checkfunction, checkint, checkinteger, checkjstring, checklong, checknotnil, checknumber, checkstring, checktable, checkthread, checkuserdata, checkuserdata, checkvalue, eval, isfunction, isnil, isnoneornil, isnumber, isstring, istable, isTailcall, isthread, isuserdata, isvalue, optboolean, optclosure, optdouble, optfunction, optint, optinteger, optjstring, optlong, optnumber, optstring, opttable, optthread, optuserdata, optuserdata, optvalue, toboolean, tobyte, tochar, todouble, tofloat, toint, tojstring, tolong, toshort, touserdata, touserdata, type

Methods inherited from class java.lang.Object

clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

p

public final Prototype p

upValues

public UpValue[] upValues

Constructor Detail

LuaClosure

public LuaClosure(Prototype p,
                  LuaValue env)

Create a closure around a Prototype with a specific environment. If the prototype has upvalues, the environment will be written into the first upvalue.

Parameters:

p - the Prototype to construct this Closure for.

env - the environment to associate with the closure.

Method Detail

isclosure

public boolean isclosure()

Description copied from class: LuaValue

Check if this is a function that is a closure, meaning interprets lua bytecode for its execution

Overrides:

isclosure in class LuaValue

Returns:

true if this is a closure, otherwise false

See Also:

LuaValue.isfunction(), LuaValue.checkclosure(), LuaValue.optclosure(LuaClosure), LuaValue.TFUNCTION

optclosure

public LuaClosure optclosure(LuaClosure defval)

Description copied from class: LuaValue

Check that optional argument is a closure and return as LuaClosure

A LuaClosure is a LuaFunction that executes lua byteccode.

Overrides:

optclosure in class LuaValue

Parameters:

defval - LuaClosure to return if this is nil or none

Returns:

this cast to LuaClosure if a function, defval if nil or none, throws LuaError otherwise

See Also:

LuaValue.checkclosure(), LuaValue.isclosure(), LuaValue.TFUNCTION

checkclosure

public LuaClosure checkclosure()

Description copied from class: LuaValue

Check that the value is a LuaClosure , or throw LuaError if not

LuaClosure is a subclass of LuaFunction that interprets lua bytecode.

Overrides:

checkclosure in class LuaValue

Returns:

this cast as LuaClosure

See Also:

LuaValue.checkfunction(), LuaValue.optclosure(LuaClosure), LuaValue.isclosure(), LuaValue.TFUNCTION

getmetatable

public LuaValue getmetatable()

Description copied from class: LuaValue

Get the metatable for this LuaValue

For LuaTable and LuaUserdata instances, the metatable returned is this instance metatable. For all other types, the class metatable value will be returned.

Overrides:

getmetatable in class LuaFunction

Returns:

metatable, or null if it there is none

See Also:

LuaBoolean.s_metatable, LuaNumber.s_metatable, LuaNil.s_metatable, LuaFunction.s_metatable, LuaThread.s_metatable

tojstring

public java.lang.String tojstring()

Description copied from class: LuaValue

Convert to human readable String for any type.

Overrides:

tojstring in class LuaFunction

Returns:

String for use by human readers based on type.

See Also:

LuaValue.tostring(), LuaValue.optjstring(String), LuaValue.checkjstring(), LuaValue.isstring(), LuaValue.TSTRING

call

public final LuaValue call()

Description copied from class: LuaValue

Call this with 0 arguments, including metatag processing, and return only the first return value.

If this is a LuaFunction, call it, and return only its first return value, dropping any others. Otherwise, look for the LuaValue.CALL metatag and call that.

If the return value is a Varargs, only the 1st value will be returned. To get multiple values, use LuaValue.invoke() instead.

To call this as a method call, use LuaValue.method(LuaValue) instead.

Overrides:

call in class LuaValue

Returns:

First return value (this()), or LuaValue.NIL if there were none.

See Also:

LuaValue.call(LuaValue), LuaValue.call(LuaValue,LuaValue), LuaValue.call(LuaValue, LuaValue, LuaValue), LuaValue.invoke(), LuaValue.method(String), LuaValue.method(LuaValue)

call

public final LuaValue call(LuaValue arg)

Description copied from class: LuaValue

Call this with 1 argument, including metatag processing, and return only the first return value.

If this is a LuaFunction, call it, and return only its first return value, dropping any others. Otherwise, look for the LuaValue.CALL metatag and call that.

If the return value is a Varargs, only the 1st value will be returned. To get multiple values, use LuaValue.invoke() instead.

To call this as a method call, use LuaValue.method(LuaValue) instead.

Overrides:

call in class LuaValue

Parameters:

arg - First argument to supply to the called function

Returns:

First return value (this(arg)), or LuaValue.NIL if there were none.

See Also:

LuaValue.call(), LuaValue.call(LuaValue,LuaValue), LuaValue.call(LuaValue, LuaValue, LuaValue), LuaValue.invoke(Varargs), LuaValue.method(String,LuaValue), LuaValue.method(LuaValue,LuaValue)

call

public final LuaValue call(LuaValue arg1,
                           LuaValue arg2)

Description copied from class: LuaValue

Call this with 2 arguments, including metatag processing, and return only the first return value.

If this is a LuaFunction, call it, and return only its first return value, dropping any others. Otherwise, look for the LuaValue.CALL metatag and call that.

If the return value is a Varargs, only the 1st value will be returned. To get multiple values, use LuaValue.invoke() instead.

To call this as a method call, use LuaValue.method(LuaValue) instead.

Overrides:

call in class LuaValue

Parameters:

arg1 - First argument to supply to the called function

arg2 - Second argument to supply to the called function

Returns:

First return value (this(arg1,arg2)), or LuaValue.NIL if there were none.

See Also:

LuaValue.call(), LuaValue.call(LuaValue), LuaValue.call(LuaValue, LuaValue, LuaValue), LuaValue.invoke(LuaValue, Varargs), LuaValue.method(String,LuaValue,LuaValue), LuaValue.method(LuaValue,LuaValue,LuaValue)

call

public final LuaValue call(LuaValue arg1,
                           LuaValue arg2,
                           LuaValue arg3)

Description copied from class: LuaValue

Call this with 3 arguments, including metatag processing, and return only the first return value.

If this is a LuaFunction, call it, and return only its first return value, dropping any others. Otherwise, look for the LuaValue.CALL metatag and call that.

If the return value is a Varargs, only the 1st value will be returned. To get multiple values, use LuaValue.invoke() instead.

To call this as a method call, use LuaValue.method(LuaValue) instead.

Overrides:

call in class LuaValue

Parameters:

arg1 - First argument to supply to the called function

arg2 - Second argument to supply to the called function

arg3 - Second argument to supply to the called function

Returns:

First return value (this(arg1,arg2,arg3)), or LuaValue.NIL if there were none.

See Also:

LuaValue.call(), LuaValue.call(LuaValue), LuaValue.call(LuaValue, LuaValue), LuaValue.invoke(LuaValue, LuaValue, Varargs), LuaValue.invokemethod(String,Varargs), LuaValue.invokemethod(LuaValue,Varargs)

invoke

public final Varargs invoke(Varargs varargs)

Description copied from class: LuaValue

Call this with variable arguments, including metatag processing, and retain all return values in a Varargs.

If this is a LuaFunction, call it, and return all values. Otherwise, look for the LuaValue.CALL metatag and call that.

To get a particular return value, us Varargs.arg(int)

To call this as a method call, use LuaValue.invokemethod(LuaValue) instead.

Overrides:

invoke in class LuaValue

Parameters:

varargs - Varargs containing the arguments to supply to the called function

Returns:

All return values as a Varargs instance.

See Also:

LuaValue.varargsOf(LuaValue[]), LuaValue.call(LuaValue), LuaValue.invoke(), LuaValue.invoke(LuaValue,Varargs), LuaValue.invokemethod(String,Varargs), LuaValue.invokemethod(LuaValue,Varargs)

onInvoke

public final Varargs onInvoke(Varargs varargs)

Description copied from class: LuaValue

Callback used during tail call processing to invoke the function once.

This may return a TailcallVarargs to be evaluated by the client.

This should not be called directly, instead use one of the call invocation functions.

Overrides:

onInvoke in class LuaValue

Parameters:

varargs - the arguments to the call invocation.

Returns:

Varargs the return values, possible a TailcallVarargs.

See Also:

LuaValue.call(), LuaValue.invoke(), LuaValue.method(LuaValue), LuaValue.invokemethod(LuaValue)

execute

protected Varargs execute(LuaValue[] stack,
                          Varargs varargs)

getUpvalue

protected LuaValue getUpvalue(int i)

setUpvalue

protected void setUpvalue(int i,
                          LuaValue v)

name

public java.lang.String name()

Description copied from class: LuaFunction

Return a human-readable name for this function. Returns the last part of the class name by default. Is overridden by LuaClosure to return the source file and line, and by LibFunctions to return the name.

Overrides:

name in class LuaFunction

Returns:

common name for this function.