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agentzhagentzh
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feature: implemented the new table.nkeys Lua API.
This Lua builtin returns the number of elements in a Lua table, i.e., the number of non-nil array elements plus the number of non-nil key-value pairs in a single Lua table. It can be used like this: local nkeys = require "table.nkeys" print(nkeys({})) -- 0 print(nkeys({ "a", nil, "b" })) -- 2 print(nkeys({ dog = 3, cat = 4, bird = nil })) -- 2 print(nkeys({ "a", dog = 3, cat = 4 })) -- 3 This Lua API can be JIT compiled. Signed-off-by: Yichun Zhang (agentzh) <agentzh@gmail.com>
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‎README

+17
Original file line numberDiff line numberDiff line change
@@ -60,6 +60,23 @@ the upstream LuaJIT (https://github.com/LuaJIT/LuaJIT), which are
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print(isarr{"dog" = 3}) -- false
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print(isarr{}) -- true
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* feature: implemented the new table.nkeys Lua API.
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This Lua builtin returns the number of elements in a Lua table, i.e.,
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the number of non-nil array elements plus the number of non-nil key-value
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pairs in a single Lua table.
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It can be used like this:
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local nkeys = require "table.nkeys"
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print(nkeys({})) -- 0
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print(nkeys({ "a", nil, "b" })) -- 2
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print(nkeys({ dog = 3, cat = 4, bird = nil })) -- 2
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print(nkeys({ "a", dog = 3, cat = 4 })) -- 3
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This Lua API can be JIT compiled.
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* feature: implemented the new Lua and C API functions for thread exdata.
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The Lua API can be used like below:

‎src/lib_table.c

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Original file line numberDiff line numberDiff line change
@@ -190,6 +190,16 @@ LJLIB_NOREG LJLIB_CF(table_isarray) LJLIB_REC(.)
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return 1;
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}
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LJLIB_NOREG LJLIB_CF(table_nkeys) LJLIB_REC(.)
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{
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GCtab *src = lj_lib_checktab(L, 1);
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setintV(L->base, lj_tab_nkeys(src));
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L->top = L->base+1;
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return 1;
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}
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LJLIB_NOREG LJLIB_CF(table_isempty) LJLIB_REC(.)
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{
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GCtab *src = lj_lib_checktab(L, 1);
@@ -340,6 +350,11 @@ static int luaopen_table_clone(lua_State *L)
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return lj_lib_postreg(L, lj_cf_table_clone, FF_table_clone, "clone");
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}
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static int luaopen_table_nkeys(lua_State *L)
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{
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return lj_lib_postreg(L, lj_cf_table_nkeys, FF_table_nkeys, "nkeys");
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}
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static int luaopen_table_isarray(lua_State *L)
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{
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return lj_lib_postreg(L, lj_cf_table_isarray, FF_table_isarray, "isarray");
@@ -369,6 +384,7 @@ LUALIB_API int luaopen_table(lua_State *L)
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lj_lib_prereg(L, LUA_TABLIBNAME ".new", luaopen_table_new, tabV(L->top-1));
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lj_lib_prereg(L, LUA_TABLIBNAME ".clone", luaopen_table_clone, tabV(L->top-1));
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lj_lib_prereg(L, LUA_TABLIBNAME ".isarray", luaopen_table_isarray, tabV(L->top-1));
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lj_lib_prereg(L, LUA_TABLIBNAME ".nkeys", luaopen_table_nkeys, tabV(L->top-1));
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lj_lib_prereg(L, LUA_TABLIBNAME ".isempty", luaopen_table_isempty, tabV(L->top-1));
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lj_lib_prereg(L, LUA_TABLIBNAME ".clear", luaopen_table_clear, tabV(L->top-1));
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return 1;

‎src/lj_ffrecord.c

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Original file line numberDiff line numberDiff line change
@@ -1126,6 +1126,14 @@ static void LJ_FASTCALL recff_table_isarray(jit_State *J, RecordFFData *rd)
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} /* else: Interpreter will throw. */
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}
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static void LJ_FASTCALL recff_table_nkeys(jit_State *J, RecordFFData *rd)
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{
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TRef src = J->base[0];
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if (LJ_LIKELY(tref_istab(src))) {
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J->base[0] = lj_ir_call(J, IRCALL_lj_tab_nkeys, src);
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} /* else: Interpreter will throw. */
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}
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static void LJ_FASTCALL recff_table_isempty(jit_State *J, RecordFFData *rd)
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{
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TRef src = J->base[0];

‎src/lj_ircall.h

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Original file line numberDiff line numberDiff line change
@@ -169,6 +169,7 @@ typedef struct CCallInfo {
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_(ANY, lj_tab_len, 1, FL, INT, 0) \
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_(ANY, lj_tab_clone, 2, FS, TAB, CCI_L) \
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_(ANY, lj_tab_isarray, 1, FL, INT, 0) \
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_(ANY, lj_tab_nkeys, 1, FL, INT, 0) \
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_(ANY, lj_tab_isempty, 1, FL, INT, 0) \
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_(ANY, lj_gc_step_jit, 2, FS, NIL, CCI_L) \
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_(ANY, lj_gc_barrieruv, 2, FS, NIL, 0) \

‎src/lj_tab.c

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Original file line numberDiff line numberDiff line change
@@ -719,6 +719,32 @@ int LJ_FASTCALL lj_tab_isarray(const GCtab *src)
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return 1;
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}
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MSize LJ_FASTCALL lj_tab_nkeys(const GCtab *t)
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{
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MSize narr = (MSize)t->asize;
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cTValue *e;
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Node *node;
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MSize i, cnt = 0;
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e = tvref(t->array);
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for (i = 0; i < narr; i++)
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if (LJ_LIKELY(!tvisnil(&e[i])))
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cnt++;
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if (t->hmask <= 0)
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return cnt;
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node = noderef(t->node);
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for (i = 0; i <= (MSize)t->hmask; i++) {
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Node *n = &node[i];
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if (LJ_LIKELY(!tvisnil(&n->val))) {
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cnt++;
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}
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}
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return cnt;
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}
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int LJ_FASTCALL lj_tab_isempty(const GCtab *t)
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{
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MSize narr = (MSize)t->asize;

‎src/lj_tab.h

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@@ -72,6 +72,7 @@ LJ_FUNCA MSize LJ_FASTCALL lj_tab_len(GCtab *t);
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LJ_FUNCA GCtab * LJ_FASTCALL lj_tab_clone(lua_State *L, const GCtab *src);
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LJ_FUNCA int LJ_FASTCALL lj_tab_isarray(const GCtab *src);
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LJ_FUNCA MSize LJ_FASTCALL lj_tab_nkeys(const GCtab *src);
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LJ_FUNCA int LJ_FASTCALL lj_tab_isempty(const GCtab *t);
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#endif

‎t/nkeys.t

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@@ -0,0 +1,175 @@
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# vim: set ss=4 ft= sw=4 et sts=4 ts=4:
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use lib '.';
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use t::TestLJ;
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plan tests => 3 * blocks();
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run_tests();
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__DATA__
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=== TEST 1: hash table, interpreted
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--- lua
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jit.off()
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local new_tab = require "table.new"
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local assert = assert
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local nkeys = require "table.nkeys"
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print(nkeys(new_tab(0, 4)))
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print(nkeys({}))
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print(nkeys({ cats = 4 }))
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print(nkeys({ dogs = 3, cats = 4 }))
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print(nkeys({ dogs = nil, cats = 4 }))
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--- jv
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--- out
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0
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0
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1
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2
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1
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--- err
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=== TEST 2: hash table, JIT
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--- lua
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jit.on()
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jit.opt.start("minstitch=100000", "hotloop=2")
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local new_tab = require "table.new"
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local assert = assert
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local nkeys = require "table.nkeys"
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local list = {
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new_tab(0, 4),
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{},
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{ cats = 4 },
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{ dogs = 3, cats = 4 },
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{ dogs = nil, cats = 4 },
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}
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for i, t in ipairs(list) do
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local total = 0
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for i = 1, 10 do
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total = total + nkeys(t)
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end
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print(total)
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end
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--- jv
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--- out
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0
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0
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10
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20
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10
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--- err
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[TRACE 1 test.lua:18 loop]
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[TRACE 2 test.lua:16 -> 1]
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=== TEST 3: pure arrays, interpreted
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--- lua
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jit.off()
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local new_tab = require "table.new"
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local assert = assert
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local nkeys = require "table.nkeys"
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print(nkeys(new_tab(5, 0)))
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print(nkeys({}))
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print(nkeys({ "cats" }))
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print(nkeys({ "dogs", 3, "cats", 4 }))
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print(nkeys({ "dogs", nil, "cats", 4 }))
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--- jv
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--- out
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0
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0
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1
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4
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3
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--- err
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=== TEST 4: pure array, JIT
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--- lua
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jit.on()
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jit.opt.start("minstitch=100000", "hotloop=2")
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local new_tab = require "table.new"
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local assert = assert
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local nkeys = require "table.nkeys"
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local list = {
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new_tab(0, 4),
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{},
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{ 3 },
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{ "cats", 4 },
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{ "dogs", 3, "cats", 4 },
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{ "dogs", nil, "cats", 4 },
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}
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for i, t in ipairs(list) do
112+
local total = 0
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for i = 1, 10 do
114+
total = total + nkeys(t)
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end
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print(total)
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end
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--- jv
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--- out
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0
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0
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10
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20
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40
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30
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--- err
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[TRACE 1 test.lua:19 loop]
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[TRACE 2 test.lua:17 -> 1]
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=== TEST 5: mixing array and hash table, interpreted
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--- lua
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jit.off()
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local new_tab = require "table.new"
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local assert = assert
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local nkeys = require "table.nkeys"
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print(nkeys({ cats = 4, 5, 6 }))
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print(nkeys({ nil, "foo", dogs = 3, cats = 4 }))
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--- jv
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--- out
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3
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3
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--- err
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=== TEST 6: mixing array & hash, JIT
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--- lua
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jit.on()
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jit.opt.start("minstitch=100000", "hotloop=2")
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local new_tab = require "table.new"
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local assert = assert
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local nkeys = require "table.nkeys"
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local list = {
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{ cats = 4, 5, 6 },
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{ nil, "foo", dogs = 3, cats = 4 },
160+
}
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for i, t in ipairs(list) do
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local total = 0
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for i = 1, 10 do
165+
total = total + nkeys(t)
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end
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print(total)
168+
end
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--- jv
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--- out
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30
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30
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--- err
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[TRACE 1 test.lua:15 loop]
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[TRACE 2 test.lua:13 -> 1]

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