add chain assignment. fix issue #115.

6 files changed, 87 insertions, 5 deletions

diff --git a/spec/inputs/assign.yue b/spec/inputs/assign.yue
index da44dff..8c7848d 100644
--- a/spec/inputs/assign.yue
+++ b/spec/inputs/assign.yue
@@ -75,3 +75,14 @@ do
                 do
                         print 123
                         1, f2!
+
+do
+        a = b = c = d = 0
+
+do
+        a = b = c = d = f!
+
+do
+        {a} = :b = c.d = e = tab
+
+nil
diff --git a/spec/outputs/assign.lua b/spec/outputs/assign.lua
index c7f2e20..e638c47 100644
--- a/spec/outputs/assign.lua
+++ b/spec/outputs/assign.lua
@@ -128,4 +128,30 @@ return _(function()
                         end
                 end
         end
+        do
+                local a = 0
+                local b = 0
+                local c = 0
+                local d = 0
+        end
+        do
+                local a
+                local b
+                local c
+                local d
+                do
+                        local _tmp_0 = f()
+                        a = _tmp_0
+                        b = _tmp_0
+                        c = _tmp_0
+                        d = _tmp_0
+                end
+        end
+        do
+                local a = tab[1]
+                local b = tab.b
+                c.d = tab
+                local e = tab
+        end
+        return nil
 end)
diff --git a/src/yuescript/yue_ast.h b/src/yuescript/yue_ast.h
index 0925f5a..21266c9 100755
--- a/src/yuescript/yue_ast.h
+++ b/src/yuescript/yue_ast.h
@@ -827,6 +827,13 @@ AST_END(YueLineComment, "comment"sv)
 AST_LEAF(YueMultilineComment)
 AST_END(YueMultilineComment, "comment"sv)
 
+AST_NODE(ChainAssign)
+        ast_ptr<true, Seperator_t> sep;
+        ast_list<true, Exp_t> exprs;
+        ast_ptr<true, Assign_t> assign;
+        AST_MEMBER(ChainAssign, &sep, &exprs, &assign)
+AST_END(ChainAssign, "chain_assign")
+
 AST_NODE(Statement)
         ast_ptr<true, Seperator_t> sep;
         ast_sel_list<false, YueLineComment_t, YueMultilineComment_t> comments;
@@ -834,7 +841,7 @@ AST_NODE(Statement)
                 Import_t, While_t, Repeat_t, For_t, ForEach_t,
                 Return_t, Local_t, Global_t, Export_t, Macro_t, MacroInPlace_t,
                 BreakLoop_t, Label_t, Goto_t, ShortTabAppending_t,
-                Backcall_t, LocalAttrib_t, PipeBody_t, ExpListAssign_t
+                Backcall_t, LocalAttrib_t, PipeBody_t, ExpListAssign_t, ChainAssign_t
         > content;
         ast_ptr<false, statement_appendix_t> appendix;
         ast_ptr<false, statement_sep_t> needSep;
diff --git a/src/yuescript/yue_compiler.cpp b/src/yuescript/yue_compiler.cpp
index 45a9bf6..4072974 100644
--- a/src/yuescript/yue_compiler.cpp
+++ b/src/yuescript/yue_compiler.cpp
@@ -59,7 +59,7 @@ namespace yue {
 
 typedef std::list<std::string> str_list;
 
-const std::string_view version = "0.15.10"sv;
+const std::string_view version = "0.15.11"sv;
 const std::string_view extension = "yue"sv;
 
 class YueCompilerImpl {
@@ -1276,6 +1276,7 @@ private:
                                 }
                                 break;
                         }
+                        case id<ChainAssign_t>(): transformChainAssign(static_cast<ChainAssign_t*>(content), out); break;
                         default: YUEE("AST node mismatch", content); break;
                 }
                 if (statement->needSep && !out.empty() && !out.back().empty()) {
@@ -8004,6 +8005,40 @@ private:
                 assignment->action.set(tab->assign);
                 transformAssignment(assignment, out);
         }
+
+        void transformChainAssign(ChainAssign_t* chainAssign, str_list& out) {
+                auto x = chainAssign;
+                str_list temp;
+                auto value = chainAssign->assign->values.front();
+                bool constVal = false;
+                if (auto simpleVal = simpleSingleValueFrom(value)) {
+                        constVal = ast_is<const_value_t, Num_t>(simpleVal->value);
+                }
+                if (constVal || !singleVariableFrom(value, false).empty()) {
+                        for (auto exp : chainAssign->exprs.objects()) {
+                                transformAssignment(assignmentFrom(static_cast<Exp_t*>(exp), value, exp), temp);
+                        }
+                        out.push_back(join(temp));
+                        return;
+                }
+                auto valName = getUnusedName("_tmp_");
+                auto newValue = toAst<Exp_t>(valName, value);
+                ast_list<false, ExpListAssign_t> assignments;
+                for (auto exp : chainAssign->exprs.objects()) {
+                        auto assignment = assignmentFrom(static_cast<Exp_t*>(exp), newValue, exp);
+                        assignments.push_back(assignment.get());
+                        temp.push_back(getPreDefineLine(assignment));
+                }
+                assignments.push_front(assignmentFrom(newValue, value, value));
+                temp.push_back(indent() + "do"s + nll(x));
+                pushScope();
+                for (auto item : assignments.objects()) {
+                        transformAssignment(static_cast<ExpListAssign_t*>(item), temp);
+                }
+                popScope();
+                temp.push_back(indent() + "end"s + nll(x));
+                out.push_back(join(temp));
+        }
 };
 
 const std::string YueCompilerImpl::Empty;
diff --git a/src/yuescript/yue_parser.cpp b/src/yuescript/yue_parser.cpp
index e755fb2..b1f29a9 100644
--- a/src/yuescript/yue_parser.cpp
+++ b/src/yuescript/yue_parser.cpp
@@ -650,7 +650,7 @@ YueParser::YueParser() {
                 unary_value | TblComprehension | TableLit | Comprehension |
                 FunLit | Num);
 
-        ExpListAssign = ExpList >> -(Update | Assign);
+        ExpListAssign = ExpList >> -(Update | Assign) >> not_(Space >> expr('='));
 
         if_line = Space >> IfType >> IfCond;
         while_line = Space >> WhileType >> Exp;
@@ -661,13 +661,15 @@ YueParser::YueParser() {
         yue_multiline_comment = multi_line_open >> YueMultilineComment >> multi_line_close;
         yue_comment = check_indent >> (yue_multiline_comment >> *(set(" \t") | yue_multiline_comment) >> -yue_line_comment | yue_line_comment) >> and_(Break);
 
+        ChainAssign = Seperator >> Exp >> +(sym('=') >> Exp >> Space >> and_('=')) >> Assign;
+
         statement_appendix = (if_line | while_line | CompInner) >> Space;
         statement_sep = and_(*SpaceBreak >> CheckIndent >> Space >> (set("($'\"") | expr("[[") | expr("[=")));
         Statement = Seperator >> -(yue_comment >> *(Break >> yue_comment) >> Break >> CheckIndent) >> Space >> (
                 Import | While | Repeat | For | ForEach |
                 Return | Local | Global | Export | Macro |
                 MacroInPlace | BreakLoop | Label | Goto | ShortTabAppending |
-                LocalAttrib | Backcall | PipeBody | ExpListAssign |
+                LocalAttrib | Backcall | PipeBody | ExpListAssign | ChainAssign |
                 statement_appendix >> empty_block_error
         ) >> Space >>
         -statement_appendix >> -statement_sep;
@@ -679,7 +681,7 @@ YueParser::YueParser() {
                 advance >> ensure(MultiLineComment >> Space | Comment, PopIndent) |
                 plain_space) >> and_(Break);
 
-        indentation_error = pl::user(not_(PipeOperator), [](const item_t& item) {
+        indentation_error = pl::user(not_(PipeOperator | eof()), [](const item_t& item) {
                 throw ParserError("unexpected indent", *item.begin, *item.end);
                 return false;
         });
diff --git a/src/yuescript/yue_parser.h b/src/yuescript/yue_parser.h
index 74281fb..88d688c 100644
--- a/src/yuescript/yue_parser.h
+++ b/src/yuescript/yue_parser.h
@@ -361,6 +361,7 @@ private:
         AST_RULE(Statement)
         AST_RULE(YueLineComment)
         AST_RULE(YueMultilineComment)
+        AST_RULE(ChainAssign)
         AST_RULE(Body)
         AST_RULE(Block)
         AST_RULE(BlockEnd)