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** $Id: lobject.h,v 2.71 2012/09/11 18:21:44 roberto Exp $
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** Type definitions for Lua objects
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** See Copyright Notice in lua.h
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** Extra tags for non-values
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#define LUA_TPROTO LUA_NUMTAGS
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#define LUA_TUPVAL (LUA_NUMTAGS+1)
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#define LUA_TDEADKEY (LUA_NUMTAGS+2)
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** number of all possible tags (including LUA_TNONE but excluding DEADKEY)
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#define LUA_TOTALTAGS (LUA_TUPVAL+2)
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** tags for Tagged Values have the following use of bits:
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** bits 0-3: actual tag (a LUA_T* value)
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** bits 4-5: variant bits
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** bit 6: whether value is collectable
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#define VARBITS (3 << 4)
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** LUA_TFUNCTION variants:
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** 1 - light C function
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** 2 - regular C function (closure)
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/* Variant tags for functions */
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#define LUA_TLCL (LUA_TFUNCTION | (0 << 4)) /* Lua closure */
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#define LUA_TLCF (LUA_TFUNCTION | (1 << 4)) /* light C function */
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#define LUA_TCCL (LUA_TFUNCTION | (2 << 4)) /* C closure */
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/* Variant tags for strings */
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#define LUA_TSHRSTR (LUA_TSTRING | (0 << 4)) /* short strings */
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#define LUA_TLNGSTR (LUA_TSTRING | (1 << 4)) /* long strings */
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/* Bit mark for collectable types */
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#define BIT_ISCOLLECTABLE (1 << 6)
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/* mark a tag as collectable */
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#define ctb(t) ((t) | BIT_ISCOLLECTABLE)
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** Union of all collectable objects
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typedef union GCObject GCObject;
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** Common Header for all collectable objects (in macro form, to be
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** included in other objects)
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#define CommonHeader GCObject *next; lu_byte tt; lu_byte marked
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** Common header in struct form
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typedef struct GCheader {
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** Union of all Lua values
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typedef union Value Value;
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#define numfield lua_Number n; /* numbers */
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** Tagged Values. This is the basic representation of values in Lua,
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** an actual value plus a tag with its type.
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#define TValuefields Value value_; int tt_
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typedef struct lua_TValue TValue;
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/* macro defining a nil value */
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#define NILCONSTANT {NULL}, LUA_TNIL
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#define val_(o) ((o)->value_)
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#define num_(o) (val_(o).n)
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/* raw type tag of a TValue */
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#define rttype(o) ((o)->tt_)
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/* tag with no variants (bits 0-3) */
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#define novariant(x) ((x) & 0x0F)
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/* type tag of a TValue (bits 0-3 for tags + variant bits 4-5) */
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#define ttype(o) (rttype(o) & 0x3F)
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/* type tag of a TValue with no variants (bits 0-3) */
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#define ttypenv(o) (novariant(rttype(o)))
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/* Macros to test type */
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#define checktag(o,t) (rttype(o) == (t))
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#define checktype(o,t) (ttypenv(o) == (t))
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#define ttisnumber(o) checktag((o), LUA_TNUMBER)
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#define ttisnil(o) checktag((o), LUA_TNIL)
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#define ttisboolean(o) checktag((o), LUA_TBOOLEAN)
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#define ttislightuserdata(o) checktag((o), LUA_TLIGHTUSERDATA)
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#define ttisstring(o) checktype((o), LUA_TSTRING)
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#define ttisshrstring(o) checktag((o), ctb(LUA_TSHRSTR))
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#define ttislngstring(o) checktag((o), ctb(LUA_TLNGSTR))
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#define ttistable(o) checktag((o), ctb(LUA_TTABLE))
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#define ttisfunction(o) checktype(o, LUA_TFUNCTION)
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#define ttisclosure(o) ((rttype(o) & 0x1F) == LUA_TFUNCTION)
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#define ttisCclosure(o) checktag((o), ctb(LUA_TCCL))
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#define ttisLclosure(o) checktag((o), ctb(LUA_TLCL))
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#define ttislcf(o) checktag((o), LUA_TLCF)
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#define ttisuserdata(o) checktag((o), ctb(LUA_TUSERDATA))
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#define ttisthread(o) checktag((o), ctb(LUA_TTHREAD))
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#define ttisdeadkey(o) checktag((o), LUA_TDEADKEY)
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#define ttisequal(o1,o2) (rttype(o1) == rttype(o2))
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/* Macros to access values */
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#define nvalue(o) check_exp(ttisnumber(o), num_(o))
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#define gcvalue(o) check_exp(iscollectable(o), val_(o).gc)
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#define pvalue(o) check_exp(ttislightuserdata(o), val_(o).p)
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#define rawtsvalue(o) check_exp(ttisstring(o), &val_(o).gc->ts)
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#define tsvalue(o) (&rawtsvalue(o)->tsv)
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#define rawuvalue(o) check_exp(ttisuserdata(o), &val_(o).gc->u)
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#define uvalue(o) (&rawuvalue(o)->uv)
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#define clvalue(o) check_exp(ttisclosure(o), &val_(o).gc->cl)
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#define clLvalue(o) check_exp(ttisLclosure(o), &val_(o).gc->cl.l)
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#define clCvalue(o) check_exp(ttisCclosure(o), &val_(o).gc->cl.c)
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#define fvalue(o) check_exp(ttislcf(o), val_(o).f)
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#define hvalue(o) check_exp(ttistable(o), &val_(o).gc->h)
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#define bvalue(o) check_exp(ttisboolean(o), val_(o).b)
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#define thvalue(o) check_exp(ttisthread(o), &val_(o).gc->th)
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/* a dead value may get the 'gc' field, but cannot access its contents */
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#define deadvalue(o) check_exp(ttisdeadkey(o), cast(void *, val_(o).gc))
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#define l_isfalse(o) (ttisnil(o) || (ttisboolean(o) && bvalue(o) == 0))
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#define iscollectable(o) (rttype(o) & BIT_ISCOLLECTABLE)
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/* Macros for internal tests */
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#define righttt(obj) (ttype(obj) == gcvalue(obj)->gch.tt)
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#define checkliveness(g,obj) \
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lua_longassert(!iscollectable(obj) || \
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(righttt(obj) && !isdead(g,gcvalue(obj))))
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/* Macros to set values */
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#define settt_(o,t) ((o)->tt_=(t))
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#define setnvalue(obj,x) \
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{ TValue *io=(obj); num_(io)=(x); settt_(io, LUA_TNUMBER); }
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#define setnilvalue(obj) settt_(obj, LUA_TNIL)
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#define setfvalue(obj,x) \
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{ TValue *io=(obj); val_(io).f=(x); settt_(io, LUA_TLCF); }
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#define setpvalue(obj,x) \
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{ TValue *io=(obj); val_(io).p=(x); settt_(io, LUA_TLIGHTUSERDATA); }
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#define setbvalue(obj,x) \
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{ TValue *io=(obj); val_(io).b=(x); settt_(io, LUA_TBOOLEAN); }
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#define setgcovalue(L,obj,x) \
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{ TValue *io=(obj); GCObject *i_g=(x); \
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val_(io).gc=i_g; settt_(io, ctb(gch(i_g)->tt)); }
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#define setsvalue(L,obj,x) \
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{ TValue *io=(obj); \
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val_(io).gc=cast(GCObject *, x_); settt_(io, ctb(x_->tsv.tt)); \
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checkliveness(G(L),io); }
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#define setuvalue(L,obj,x) \
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{ TValue *io=(obj); \
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val_(io).gc=cast(GCObject *, (x)); settt_(io, ctb(LUA_TUSERDATA)); \
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checkliveness(G(L),io); }
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#define setthvalue(L,obj,x) \
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{ TValue *io=(obj); \
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val_(io).gc=cast(GCObject *, (x)); settt_(io, ctb(LUA_TTHREAD)); \
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checkliveness(G(L),io); }
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#define setclLvalue(L,obj,x) \
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{ TValue *io=(obj); \
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val_(io).gc=cast(GCObject *, (x)); settt_(io, ctb(LUA_TLCL)); \
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checkliveness(G(L),io); }
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#define setclCvalue(L,obj,x) \
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{ TValue *io=(obj); \
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val_(io).gc=cast(GCObject *, (x)); settt_(io, ctb(LUA_TCCL)); \
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checkliveness(G(L),io); }
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#define sethvalue(L,obj,x) \
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{ TValue *io=(obj); \
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val_(io).gc=cast(GCObject *, (x)); settt_(io, ctb(LUA_TTABLE)); \
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checkliveness(G(L),io); }
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#define setdeadvalue(obj) settt_(obj, LUA_TDEADKEY)
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#define setobj(L,obj1,obj2) \
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{ const TValue *io2=(obj2); TValue *io1=(obj1); \
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io1->value_ = io2->value_; io1->tt_ = io2->tt_; \
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checkliveness(G(L),io1); }
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** different types of assignments, according to destination
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/* from stack to (same) stack */
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#define setobjs2s setobj
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/* to stack (not from same stack) */
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#define setobj2s setobj
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#define setsvalue2s setsvalue
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#define sethvalue2s sethvalue
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#define setptvalue2s setptvalue
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/* from table to same table */
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#define setobjt2t setobj
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#define setobj2t setobj
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#define setobj2n setobj
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#define setsvalue2n setsvalue
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/* check whether a number is valid (useful only for NaN trick) */
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#define luai_checknum(L,o,c) { /* empty */ }
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** {======================================================
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** =======================================================
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#if defined(LUA_NANTRICK)
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** numbers are represented in the 'd_' field. All other values have the
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** value (NNMARK | tag) in 'tt__'. A number with such pattern would be
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** a "signaled NaN", which is never generated by regular operations by
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** the CPU (nor by 'strtod')
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/* allows for external implementation for part of the trick */
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#if !defined(NNMARK) /* { */
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#if !defined(LUA_IEEEENDIAN)
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#error option 'LUA_NANTRICK' needs 'LUA_IEEEENDIAN'
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#define NNMARK 0x7FF7A500
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#define NNMASK 0x7FFFFF00
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#if (LUA_IEEEENDIAN == 0) /* { */
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#define TValuefields \
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union { struct { Value v__; int tt__; } i; double d__; } u
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#define NILCONSTANT {{{NULL}, tag2tt(LUA_TNIL)}}
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/* field-access macros */
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#define v_(o) ((o)->u.i.v__)
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#define d_(o) ((o)->u.d__)
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#define tt_(o) ((o)->u.i.tt__)
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#define TValuefields \
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union { struct { int tt__; Value v__; } i; double d__; } u
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#define NILCONSTANT {{tag2tt(LUA_TNIL), {NULL}}}
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/* field-access macros */
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#define v_(o) ((o)->u.i.v__)
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#define d_(o) ((o)->u.d__)
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#define tt_(o) ((o)->u.i.tt__)
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/* correspondence with standard representation */
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#define val_(o) v_(o)
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#define num_(o) d_(o)
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#define numfield /* no such field; numbers are the entire struct */
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/* basic check to distinguish numbers from non-numbers */
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#define ttisnumber(o) ((tt_(o) & NNMASK) != NNMARK)
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#define tag2tt(t) (NNMARK | (t))
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#define rttype(o) (ttisnumber(o) ? LUA_TNUMBER : tt_(o) & 0xff)
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#define settt_(o,t) (tt_(o) = tag2tt(t))
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#define setnvalue(obj,x) \
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{ TValue *io_=(obj); num_(io_)=(x); lua_assert(ttisnumber(io_)); }
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#define setobj(L,obj1,obj2) \
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{ const TValue *o2_=(obj2); TValue *o1_=(obj1); \
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checkliveness(G(L),o1_); }
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** these redefinitions are not mandatory, but these forms are more efficient
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#define checktag(o,t) (tt_(o) == tag2tt(t))
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#define checktype(o,t) (ctb(tt_(o) | VARBITS) == ctb(tag2tt(t) | VARBITS))
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#define ttisequal(o1,o2) \
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(ttisnumber(o1) ? ttisnumber(o2) : (tt_(o1) == tt_(o2)))
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#define luai_checknum(L,o,c) { if (!ttisnumber(o)) c; }
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/* }====================================================== */
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** {======================================================
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** types and prototypes
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** =======================================================
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GCObject *gc; /* collectable objects */
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void *p; /* light userdata */
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int b; /* booleans */
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lua_CFunction f; /* light C functions */
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numfield /* numbers */
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typedef TValue *StkId; /* index to stack elements */
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** Header for string value; string bytes follow the end of this structure
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typedef union TString {
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L_Umaxalign dummy; /* ensures maximum alignment for strings */
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lu_byte extra; /* reserved words for short strings; "has hash" for longs */
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size_t len; /* number of characters in string */
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/* get the actual string (array of bytes) from a TString */
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#define getstr(ts) cast(const char *, (ts) + 1)
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/* get the actual string (array of bytes) from a Lua value */
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#define svalue(o) getstr(rawtsvalue(o))
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** Header for userdata; memory area follows the end of this structure
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typedef union Udata {
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L_Umaxalign dummy; /* ensures maximum alignment for `local' udata */
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struct Table *metatable;
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size_t len; /* number of bytes */
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** Description of an upvalue for function prototypes
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typedef struct Upvaldesc {
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TString *name; /* upvalue name (for debug information) */
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lu_byte instack; /* whether it is in stack */
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lu_byte idx; /* index of upvalue (in stack or in outer function's list) */
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** Description of a local variable for function prototypes
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** (used for debug information)
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typedef struct LocVar {
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int startpc; /* first point where variable is active */
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int endpc; /* first point where variable is dead */
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** Function Prototypes
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typedef struct Proto {
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TValue *k; /* constants used by the function */
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struct Proto **p; /* functions defined inside the function */
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int *lineinfo; /* map from opcodes to source lines (debug information) */
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LocVar *locvars; /* information about local variables (debug information) */
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Upvaldesc *upvalues; /* upvalue information */
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union Closure *cache; /* last created closure with this prototype */
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TString *source; /* used for debug information */
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int sizeupvalues; /* size of 'upvalues' */
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int sizek; /* size of `k' */
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int sizep; /* size of `p' */
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lu_byte numparams; /* number of fixed parameters */
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lu_byte maxstacksize; /* maximum stack used by this function */
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typedef struct UpVal {
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TValue *v; /* points to stack or to its own value */
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TValue value; /* the value (when closed) */
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struct { /* double linked list (when open) */
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#define ClosureHeader \
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CommonHeader; lu_byte nupvalues; GCObject *gclist
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typedef struct CClosure {
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TValue upvalue[1]; /* list of upvalues */
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typedef struct LClosure {
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UpVal *upvals[1]; /* list of upvalues */
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typedef union Closure {
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#define isLfunction(o) ttisLclosure(o)
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#define getproto(o) (clLvalue(o)->p)
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struct Node *next; /* for chaining */
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typedef struct Node {
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typedef struct Table {
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lu_byte flags; /* 1<<p means tagmethod(p) is not present */
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lu_byte lsizenode; /* log2 of size of `node' array */
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struct Table *metatable;
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TValue *array; /* array part */
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Node *lastfree; /* any free position is before this position */
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int sizearray; /* size of `array' array */
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** `module' operation for hashing (size is always a power of 2)
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#define lmod(s,size) \
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(check_exp((size&(size-1))==0, (cast(int, (s) & ((size)-1)))))
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#define twoto(x) (1<<(x))
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#define sizenode(t) (twoto((t)->lsizenode))
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** (address of) a fixed nil value
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#define luaO_nilobject (&luaO_nilobject_)
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LUAI_DDEC const TValue luaO_nilobject_;
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LUAI_FUNC int luaO_int2fb (unsigned int x);
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LUAI_FUNC int luaO_fb2int (int x);
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LUAI_FUNC int luaO_ceillog2 (unsigned int x);
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LUAI_FUNC lua_Number luaO_arith (int op, lua_Number v1, lua_Number v2);
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LUAI_FUNC int luaO_str2d (const char *s, size_t len, lua_Number *result);
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LUAI_FUNC int luaO_hexavalue (int c);
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LUAI_FUNC const char *luaO_pushvfstring (lua_State *L, const char *fmt,
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LUAI_FUNC const char *luaO_pushfstring (lua_State *L, const char *fmt, ...);
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LUAI_FUNC void luaO_chunkid (char *out, const char *source, size_t len);