diff options
| -rw-r--r-- | README.md | 2 | ||||
| -rw-r--r-- | src/ltablib.js | 16 | ||||
| -rw-r--r-- | tests/ltablib.js | 41 |
3 files changed, 57 insertions, 2 deletions
@@ -206,11 +206,11 @@ - [ ] Table - [x] table.concat - [x] table.pack + - [x] table.unpack - [ ] table.insert - [ ] table.move - [ ] table.remove - [ ] table.sort - - [ ] table.unpack - [ ] Debug (errors) - [ ] DOM API binding - [ ] Parse Lua diff --git a/src/ltablib.js b/src/ltablib.js index ec7c578..86b57d7 100644 --- a/src/ltablib.js +++ b/src/ltablib.js @@ -91,9 +91,23 @@ const pack = function(L) { return 1; /* return table */ }; +const unpack = function(L) { + let i = lauxlib.luaL_optinteger(L, 2, 1); + let e = lauxlib.luaL_opt(L, lauxlib.luaL_checkinteger, 3, lapi.lua_len(L, 1)); + if (i > e) return 0; /* empty range */ + let n = e - i; /* number of elements minus 1 (avoid overflows) */ + if (n >= Number.MAX_SAFE_INTEGER || !lapi.lua_checkstack(L, ++n)) + return lauxlib.luaL_error(L, "too many results to unpack"); + for (; i < e; i++) /* push arg[i..e - 1] (to avoid overflows) */ + lapi.lua_geti(L, 1, i); + lapi.lua_geti(L, 1, e); /* push last element */ + return n; +}; + const tab_funcs = { "concat": tconcat, - "pack": pack + "pack": pack, + "unpack": unpack, }; const luaopen_table = function(L) { diff --git a/tests/ltablib.js b/tests/ltablib.js index 28b9ce0..8221fe0 100644 --- a/tests/ltablib.js +++ b/tests/ltablib.js @@ -75,4 +75,45 @@ test('table.pack', function (t) { [1, 2, 3], "Correct element(s) on the stack" ); +}); + + +test('table.unpack', function (t) { + let luaCode = ` + return table.unpack({1, 2, 3, 4, 5}, 2, 4) + `, L; + + t.plan(4); + + t.doesNotThrow(function () { + + let bc = toByteCode(luaCode).dataView; + + L = lauxlib.luaL_newstate(); + + linit.luaL_openlibs(L); + + lapi.lua_load(L, bc, "test-table.unpack"); + + lapi.lua_call(L, 0, -1); + + }, "JS Lua program ran without error"); + + t.strictEqual( + lapi.lua_tointeger(L, -3), + 2, + "Correct element(s) on the stack" + ); + + t.strictEqual( + lapi.lua_tointeger(L, -2), + 3, + "Correct element(s) on the stack" + ); + + t.strictEqual( + lapi.lua_tointeger(L, -1), + 4, + "Correct element(s) on the stack" + ); });
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