org.luaj.vm2.lib
Class MathLib

java.lang.Object
  org.luaj.vm2.Varargs
      org.luaj.vm2.LuaValue
          org.luaj.vm2.LuaFunction
              org.luaj.vm2.lib.LibFunction
                  org.luaj.vm2.lib.TwoArgFunction
                      org.luaj.vm2.lib.MathLib

Direct Known Subclasses:

JseMathLib

public class MathLib
extends TwoArgFunction

Subclass of LibFunction which implements the lua standard math library.

It contains only the math library support that is possible on JME. For a more complete implementation based on math functions specific to JSE use JseMathLib. In Particular the following math functions are not implemented by this library:

• acos
• asin
• atan
• cosh
• log
• sinh
• tanh
• atan2

The implementations of exp() and pow() are constructed by hand for JME, so will be slower and less accurate than when executed on the JSE platform.

Typically, this library is included as part of a call to either JsePlatform.standardGlobals() or JmePlatform.standardGlobals()

 Globals globals = JsePlatform.standardGlobals();
 System.out.println( globals.get("math").get("sqrt").call( LuaValue.valueOf(2) ) );
  

When using JsePlatform as in this example, the subclass JseMathLib will be included, which also includes this base functionality.

To instantiate and use it directly, link it into your globals table via LuaValue.load(LuaValue) using code such as:

 Globals globals = new Globals();
 globals.load(new JseBaseLib());
 globals.load(new PackageLib());
 globals.load(new MathLib());
 System.out.println( globals.get("math").get("sqrt").call( LuaValue.valueOf(2) ) );
  

Doing so will ensure the library is properly initialized and loaded into the globals table.

This has been implemented to match as closely as possible the behavior in the corresponding library in C.

See Also:

LibFunction, JsePlatform, JmePlatform, JseMathLib, Lua 5.2 Math Lib Reference

Nested Class Summary

protected static class	MathLib.BinaryOp
protected static class	MathLib.UnaryOp

Field Summary

static MathLib

MATHLIB Pointer to the latest MathLib instance, used only to dispatch math.exp to tha correct platform math library.

Fields inherited from class org.luaj.vm2.lib.LibFunction

name, opcode

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

MathLib()
Construct a MathLib, which can be initialized by calling it with a modname string, and a global environment table as arguments using call(LuaValue, LuaValue).

Method Summary

LuaValue	call(LuaValue modname, LuaValue env) 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.
static double	dpow_d(double a, double b)
protected static double	dpow_default(double a, double b) Default JME version computes using longhand heuristics.
double	dpow_lib(double a, double b) Hook to override default dpow behavior with faster implementation.
static LuaValue	dpow(double a, double b) compute power using installed math library, or default if there is no math library installed

Methods inherited from class org.luaj.vm2.lib.TwoArgFunction

call, call, call, invoke

Methods inherited from class org.luaj.vm2.lib.LibFunction

bind, bind, call, newupe, newupl, newupn, tojstring

Methods inherited from class org.luaj.vm2.LuaFunction

checkfunction, classnamestub, getmetatable, isfunction, name, 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, checkclosure, 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, isclosure, 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, onInvoke, optboolean, optclosure, 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

MATHLIB

public static MathLib MATHLIB

Pointer to the latest MathLib instance, used only to dispatch math.exp to tha correct platform math library.

Constructor Detail

MathLib

public MathLib()

Construct a MathLib, which can be initialized by calling it with a modname string, and a global environment table as arguments using call(LuaValue, LuaValue).

Method Detail

call

public LuaValue call(LuaValue modname,
                     LuaValue env)

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.

Specified by:

call in class TwoArgFunction

Parameters:

modname - the module name supplied if this is loaded via 'require'.

env - the environment to load into, typically a Globals instance.

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)

dpow

public static LuaValue dpow(double a,
                            double b)

compute power using installed math library, or default if there is no math library installed

dpow_d

public static double dpow_d(double a,
                            double b)

dpow_lib

public double dpow_lib(double a,
                       double b)

Hook to override default dpow behavior with faster implementation.

dpow_default

protected static double dpow_default(double a,
                                     double b)

Default JME version computes using longhand heuristics.