9 files changed, 338 insertions, 16 deletions

diff --git a/doc/docs/doc/README.md b/doc/docs/doc/README.md
index ad26be5..2a3047a 100755
--- a/doc/docs/doc/README.md
+++ b/doc/docs/doc/README.md
@@ -595,6 +595,23 @@ tab[] = "Value"
 </pre>
 </YueDisplay>
 
+You can also use the spread operator `...` to append all elements from one list to another:
+
+```moonscript
+tbA = [1, 2, 3]
+tbB = [4, 5, 6]
+tbA[] = ...tbB
+-- tbA is now [1, 2, 3, 4, 5, 6]
+```
+<YueDisplay>
+<pre>
+tbA = [1, 2, 3]
+tbB = [4, 5, 6]
+tbA[] = ...tbB
+-- tbA is now [1, 2, 3, 4, 5, 6]
+</pre>
+</YueDisplay>
+
 ### Table Spreading
 
 You can concatenate array tables or hash tables using spread operator `...` before expressions in table literals.
@@ -2465,6 +2482,27 @@ doubled = [item * 2 for item in *items]
 </pre>
 </YueDisplay>
 
+In list comprehensions, you can also use the spread operator `...` to flatten nested lists, achieving a flat map effect:
+
+```moonscript
+data =
+  a: {1,2,3}
+  b: {4,5,6}
+
+flat = [...v for k,v in pairs data]
+-- flat is now [1, 2, 3, 4, 5, 6]
+```
+<YueDisplay>
+<pre>
+data =
+  a: {1,2,3}
+  b: {4,5,6}
+
+flat = [...v for k,v in pairs data]
+-- flat is now [1, 2, 3, 4, 5, 6]
+</pre>
+</YueDisplay>
+
 The for and when clauses can be chained as much as desired. The only requirement is that a comprehension has at least one for clause.
 
 Using multiple for clauses is the same as using nested loops:
diff --git a/doc/docs/zh/doc/README.md b/doc/docs/zh/doc/README.md
index 86796e9..a799a5b 100755
--- a/doc/docs/zh/doc/README.md
+++ b/doc/docs/zh/doc/README.md
@@ -594,6 +594,23 @@ tab[] = "Value"
 </pre>
 </YueDisplay>
 
+你还可以使用展开操作符 `...` 来将一个列表中的所有元素追加到另一个列表中：
+
+```moonscript
+tbA = [1, 2, 3]
+tbB = [4, 5, 6]
+tbA[] = ...tbB
+-- tbA 现在为 [1, 2, 3, 4, 5, 6]
+```
+<YueDisplay>
+<pre>
+tbA = [1, 2, 3]
+tbB = [4, 5, 6]
+tbA[] = ...tbB
+-- tbA 现在为 [1, 2, 3, 4, 5, 6]
+</pre>
+</YueDisplay>
+
 ### 表扩展
 
 你可以使用前置 `...` 操作符在Lua表中插入数组表或哈希表。
@@ -2425,6 +2442,27 @@ doubled = [item * 2 for item in *items]
 </pre>
 </YueDisplay>
 
+在列表推导式中，你还可以使用展开操作符 `...` 来实现对列表嵌套层级进行扁平化的处理：
+
+```moonscript
+data =
+  a: {1,2,3}
+  b: {4,5,6}
+
+flat = [...v for k,v in pairs data]
+-- flat 现在为 [1, 2, 3, 4, 5, 6]
+```
+<YueDisplay>
+<pre>
+data =
+  a: {1,2,3}
+  b: {4,5,6}
+
+flat = [...v for k,v in pairs data]
+-- flat 现在为 [1, 2, 3, 4, 5, 6]
+</pre>
+</YueDisplay>
+
 for和when子句可以根据需要进行链式操作。唯一的要求是推导式中至少要有一个for子句。
 
 使用多个for子句与使用多重循环的效果相同：
diff --git a/spec/inputs/lists.yue b/spec/inputs/lists.yue
index f754cc1..dd951a5 100644
--- a/spec/inputs/lists.yue
+++ b/spec/inputs/lists.yue
@@ -267,4 +267,14 @@ do
         f = -> globalTB[#][#] = 1
         f1 = -> globalTB[#][# - 1]
 
+do
+        tbA[] = ...tbB
+        a, tb[], b[], c = 1, ...x, 3, 4
+
+        data =
+                a: {1,2,3}
+                b: {4,5,6}
+
+        flat = [...v for k,v in pairs data]
+
 nil
diff --git a/spec/outputs/codes_from_doc.lua b/spec/outputs/codes_from_doc.lua
index 3971bb7..00b3b8b 100644
--- a/spec/outputs/codes_from_doc.lua
+++ b/spec/outputs/codes_from_doc.lua
@@ -147,6 +147,21 @@ print((function()
 end)())
 local tab = { }
 tab[#tab + 1] = "Value"
+local tbA = {
+        1,
+        2,
+        3
+}
+local tbB = {
+        4,
+        5,
+        6
+}
+local _len_0 = #tbA + 1
+for _index_0 = 1, #tbB do
+        local _elm_0 = tbB[_index_0]
+        tbA[_len_0], _len_0 = _elm_0, _len_0 + 1
+end
 local parts = {
         "shoulders",
         "knees"
@@ -1080,6 +1095,33 @@ for _index_0 = 1, #_list_0 do
         _len_0 = _len_0 + 1
 end
 doubled = _accum_0
+local data = {
+        a = {
+                1,
+                2,
+                3
+        },
+        b = {
+                4,
+                5,
+                6
+        }
+}
+local flat
+local _accum_0 = { }
+local _len_0 = 1
+for k, v in pairs(data) do
+        do
+                local _obj_0 = _accum_0[_len_0]
+                local _len_1 = #_obj_0 + 1
+                for _index_0 = 1, #v do
+                        local _elm_0 = v[_index_0]
+                        _obj_0[_len_1], _len_1 = _elm_0, _len_1 + 1
+                end
+        end
+        _len_0 = _len_0 + 1
+end
+flat = _accum_0
 local x_coords = {
         4,
         5,
@@ -2588,6 +2630,21 @@ print((function()
 end)())
 local tab = { }
 tab[#tab + 1] = "Value"
+local tbA = {
+        1,
+        2,
+        3
+}
+local tbB = {
+        4,
+        5,
+        6
+}
+local _len_0 = #tbA + 1
+for _index_0 = 1, #tbB do
+        local _elm_0 = tbB[_index_0]
+        tbA[_len_0], _len_0 = _elm_0, _len_0 + 1
+end
 local parts = {
         "shoulders",
         "knees"
@@ -3551,6 +3608,33 @@ for _index_0 = 1, #_list_0 do
         _len_0 = _len_0 + 1
 end
 doubled = _accum_0
+local data = {
+        a = {
+                1,
+                2,
+                3
+        },
+        b = {
+                4,
+                5,
+                6
+        }
+}
+local flat
+local _accum_0 = { }
+local _len_0 = 1
+for k, v in pairs(data) do
+        do
+                local _obj_0 = _accum_0[_len_0]
+                local _len_1 = #_obj_0 + 1
+                for _index_0 = 1, #v do
+                        local _elm_0 = v[_index_0]
+                        _obj_0[_len_1], _len_1 = _elm_0, _len_1 + 1
+                end
+        end
+        _len_0 = _len_0 + 1
+end
+flat = _accum_0
 local x_coords = {
         4,
         5,
diff --git a/spec/outputs/codes_from_doc_zh.lua b/spec/outputs/codes_from_doc_zh.lua
index 403ad3e..c382bca 100644
--- a/spec/outputs/codes_from_doc_zh.lua
+++ b/spec/outputs/codes_from_doc_zh.lua
@@ -147,6 +147,21 @@ print((function()
 end)())
 local tab = { }
 tab[#tab + 1] = "Value"
+local tbA = {
+        1,
+        2,
+        3
+}
+local tbB = {
+        4,
+        5,
+        6
+}
+local _len_0 = #tbA + 1
+for _index_0 = 1, #tbB do
+        local _elm_0 = tbB[_index_0]
+        tbA[_len_0], _len_0 = _elm_0, _len_0 + 1
+end
 local parts = {
         "shoulders",
         "knees"
@@ -1074,6 +1089,33 @@ for _index_0 = 1, #_list_0 do
         _len_0 = _len_0 + 1
 end
 doubled = _accum_0
+local data = {
+        a = {
+                1,
+                2,
+                3
+        },
+        b = {
+                4,
+                5,
+                6
+        }
+}
+local flat
+local _accum_0 = { }
+local _len_0 = 1
+for k, v in pairs(data) do
+        do
+                local _obj_0 = _accum_0[_len_0]
+                local _len_1 = #_obj_0 + 1
+                for _index_0 = 1, #v do
+                        local _elm_0 = v[_index_0]
+                        _obj_0[_len_1], _len_1 = _elm_0, _len_1 + 1
+                end
+        end
+        _len_0 = _len_0 + 1
+end
+flat = _accum_0
 local x_coords = {
         4,
         5,
@@ -2582,6 +2624,21 @@ print((function()
 end)())
 local tab = { }
 tab[#tab + 1] = "Value"
+local tbA = {
+        1,
+        2,
+        3
+}
+local tbB = {
+        4,
+        5,
+        6
+}
+local _len_0 = #tbA + 1
+for _index_0 = 1, #tbB do
+        local _elm_0 = tbB[_index_0]
+        tbA[_len_0], _len_0 = _elm_0, _len_0 + 1
+end
 local parts = {
         "shoulders",
         "knees"
@@ -3539,6 +3596,33 @@ for _index_0 = 1, #_list_0 do
         _len_0 = _len_0 + 1
 end
 doubled = _accum_0
+local data = {
+        a = {
+                1,
+                2,
+                3
+        },
+        b = {
+                4,
+                5,
+                6
+        }
+}
+local flat
+local _accum_0 = { }
+local _len_0 = 1
+for k, v in pairs(data) do
+        do
+                local _obj_0 = _accum_0[_len_0]
+                local _len_1 = #_obj_0 + 1
+                for _index_0 = 1, #v do
+                        local _elm_0 = v[_index_0]
+                        _obj_0[_len_1], _len_1 = _elm_0, _len_1 + 1
+                end
+        end
+        _len_0 = _len_0 + 1
+end
+flat = _accum_0
 local x_coords = {
         4,
         5,
diff --git a/spec/outputs/lists.lua b/spec/outputs/lists.lua
index 2dd19e5..6115700 100644
--- a/spec/outputs/lists.lua
+++ b/spec/outputs/lists.lua
@@ -857,4 +857,53 @@ do
                 end
         end
 end
+do
+        do
+                local _obj_0 = tbA
+                local _len_0 = #_obj_0 + 1
+                local _list_0 = tbB
+                for _index_0 = 1, #_list_0 do
+                        local _elm_0 = _list_0[_index_0]
+                        _obj_0[_len_0], _len_0 = _elm_0, _len_0 + 1
+                end
+        end
+        a = 1
+        do
+                local _obj_0 = tb
+                local _len_0 = #_obj_0 + 1
+                for _index_0 = 1, #x do
+                        local _elm_0 = x[_index_0]
+                        _obj_0[_len_0], _len_0 = _elm_0, _len_0 + 1
+                end
+        end
+        b[#b + 1] = 3
+        c = 4
+        local data = {
+                a = {
+                        1,
+                        2,
+                        3
+                },
+                b = {
+                        4,
+                        5,
+                        6
+                }
+        }
+        local flat
+        local _accum_0 = { }
+        local _len_0 = 1
+        for k, v in pairs(data) do
+                do
+                        local _obj_0 = _accum_0[_len_0]
+                        local _len_1 = #_obj_0 + 1
+                        for _index_0 = 1, #v do
+                                local _elm_0 = v[_index_0]
+                                _obj_0[_len_1], _len_1 = _elm_0, _len_1 + 1
+                        end
+                end
+                _len_0 = _len_0 + 1
+        end
+        flat = _accum_0
+end
 return nil
diff --git a/src/yuescript/yue_ast.h b/src/yuescript/yue_ast.h
index b1a369b..0008fd6 100644
--- a/src/yuescript/yue_ast.h
+++ b/src/yuescript/yue_ast.h
@@ -443,7 +443,7 @@ AST_END(CompInner)
 
 AST_NODE(Assign)
         ast_ptr<true, Seperator_t> sep;
-        ast_sel_list<true, With_t, If_t, Switch_t, TableBlock_t, Exp_t> values;
+        ast_sel_list<true, With_t, If_t, Switch_t, TableBlock_t, Exp_t, SpreadListExp_t> values;
         AST_MEMBER(Assign, &sep, &values)
 AST_END(Assign)
 
diff --git a/src/yuescript/yue_compiler.cpp b/src/yuescript/yue_compiler.cpp
index ed0a587..8c28e61 100644
--- a/src/yuescript/yue_compiler.cpp
+++ b/src/yuescript/yue_compiler.cpp
@@ -78,7 +78,7 @@ static std::unordered_set<std::string> Metamethods = {
         "close"s // Lua 5.4
 };
 
-const std::string_view version = "0.29.7"sv;
+const std::string_view version = "0.29.8"sv;
 const std::string_view extension = "yue"sv;
 
 class CompileError : public std::logic_error {
@@ -2321,15 +2321,27 @@ private:
                                                 transformAssignment(newAssignment, temp);
                                                 varName = objVar;
                                         }
-                                        auto newAssignment = x->new_ptr<ExpListAssign_t>();
-                                        newAssignment->expList.set(toAst<ExpList_t>(varName + "[#"s + varName + "+1]"s, x));
-                                        auto assign = x->new_ptr<Assign_t>();
-                                        if (vit == values.end()) {
-                                                throw CompileError("right value missing"sv, values.front());
+                                        if (auto spread = ast_cast<SpreadListExp_t>(*vit)) {
+                                                auto lenVar = getUnusedName("_len_"sv);
+                                                forceAddToScope(lenVar);
+                                                temp.push_back(indent() + "local "s + lenVar + " = #"s + varName + " + 1"s + nll(spread));
+                                                auto elmVar = getUnusedName("_elm_"sv);
+                                                _buf << varName << '[' << lenVar << "],"s << lenVar << "="s << elmVar << ',' << lenVar << "+1 for "s << elmVar << " in *nil"s;
+                                                auto stmt = toAst<Statement_t>(clearBuf(), spread);
+                                                auto comp = stmt->appendix->item.to<CompInner_t>();
+                                                ast_to<CompForEach_t>(comp->items.front())->loopValue.to<StarExp_t>()->value.set(spread->exp);
+                                                transformStatement(stmt, temp);
+                                        } else {
+                                                auto newAssignment = x->new_ptr<ExpListAssign_t>();
+                                                newAssignment->expList.set(toAst<ExpList_t>(varName + "[#"s + varName + "+1]"s, x));
+                                                auto assign = x->new_ptr<Assign_t>();
+                                                if (vit == values.end()) {
+                                                        throw CompileError("right value missing"sv, values.front());
+                                                }
+                                                assign->values.push_back(*vit);
+                                                newAssignment->action.set(assign);
+                                                transformAssignment(newAssignment, temp);
                                         }
-                                        assign->values.push_back(*vit);
-                                        newAssignment->action.set(assign);
-                                        transformAssignment(newAssignment, temp);
                                         if (extraScoped) {
                                                 popScope();
                                                 temp.push_back(indent() + "end"s + nlr(x));
@@ -2848,6 +2860,7 @@ private:
                         case id<Switch_t>(): transformSwitch(static_cast<Switch_t*>(value), out, ExpUsage::Closure); break;
                         case id<TableBlock_t>(): transformTableBlock(static_cast<TableBlock_t*>(value), out); break;
                         case id<Exp_t>(): transformExp(static_cast<Exp_t*>(value), out, ExpUsage::Closure); break;
+                        case id<SpreadListExp_t>(): throw CompileError("can only be used for ranged table append assignments"sv, value); break;
                         default: YUEE("AST node mismatch", value); break;
                 }
         }
@@ -8268,9 +8281,16 @@ private:
                         }
                         return;
                 }
-                auto def = ast_cast<NormalDef_t>(comp->items.front());
-                if (!def || def->defVal) {
-                        throw CompileError("invalid comprehension expression", comp->items.front());
+                ast_node* value = nullptr;
+                bool isSpread = ast_is<SpreadListExp_t>(comp->items.front());
+                if (isSpread) {
+                        value = comp->items.front();
+                } else {
+                        auto def = ast_cast<NormalDef_t>(comp->items.front());
+                        if (!def || def->defVal) {
+                                throw CompileError("invalid comprehension expression", comp->items.front());
+                        }
+                        value = def->item.get();
                 }
                 bool extraScope = false;
                 switch (usage) {
@@ -8294,7 +8314,6 @@ private:
                         default:
                                 break;
                 }
-                auto value = def->item.get();
                 auto compInner = static_cast<CompInner_t*>(comp->items.back());
                 str_list temp;
                 std::string accumVar = getUnusedName("_accum_"sv);
@@ -8318,7 +8337,7 @@ private:
                         }
                 }
                 {
-                        auto assignLeft = toAst<ExpList_t>(accumVar + '[' + lenVar + ']', x);
+                        auto assignLeft = toAst<ExpList_t>(accumVar + '[' + lenVar + (isSpread ? "][]"s : "]"s), x);
                         auto assign = x->new_ptr<Assign_t>();
                         assign->values.push_back(value);
                         auto assignment = x->new_ptr<ExpListAssign_t>();
diff --git a/src/yuescript/yue_parser.cpp b/src/yuescript/yue_parser.cpp
index 44baced..fccb6fb 100644
--- a/src/yuescript/yue_parser.cpp
+++ b/src/yuescript/yue_parser.cpp
@@ -547,7 +547,7 @@ YueParser::YueParser() {
 
         Assign = '=' >> space >> Seperator >> (
                 With | If | Switch | TableBlock |
-                Exp >> *(space >> set(",;") >> space >> Exp)
+                (SpreadListExp | Exp) >> *(space >> set(",;") >> space >> (SpreadListExp | Exp))
         );
 
         UpdateOp =