1 files changed, 30 insertions, 20 deletions

diff --git a/src/yuescript/yue_parser.cpp b/src/yuescript/yue_parser.cpp
index 07fcd27..b134ee2 100755..100644
--- a/src/yuescript/yue_parser.cpp
+++ b/src/yuescript/yue_parser.cpp
@@ -71,6 +71,11 @@ YueParser::YueParser() {
         Cut = false_();
         Seperator = true_();
 
+        invalid_empty_block = pl::user(true_(), [](const item_t& item) {
+                throw ParserError("must be followed by a statement or an indented block", *item.begin, *item.end);
+                return false;
+        });
+
         #define sym(str) (Space >> str)
         #define symx(str) expr(str)
         #define ensure(patt, finally) ((patt) >> (finally) | (finally) >> Cut)
@@ -79,12 +84,13 @@ YueParser::YueParser() {
         #define disable_chain(patt) (DisableChain >> ((patt) >> EnableChain | EnableChain >> Cut))
         #define disable_do_chain_arg_table_block(patt) (DisableDoChainArgTableBlock >> ((patt) >> EnableDoChainArgTableBlock | EnableDoChainArgTableBlock >> Cut))
         #define disable_arg_table_block(patt) (DisableArgTableBlock >> ((patt) >> EnableArgTableBlock | EnableArgTableBlock >> Cut))
-        #define plain_body_with(str) (-(Space >> key(str)) >> InBlock | Space >> key(str) >> Space >> Statement)
-        #define plain_body (InBlock | Space >> Statement)
+        #define body_with(str) (Space >> (key(str) >> Space >> (InBlock | Statement) | InBlock | invalid_empty_block))
+        #define opt_body_with(str) (Space >> (key(str) >> Space >> (InBlock | Statement) | InBlock))
+        #define body (Space >> (InBlock | Statement | invalid_empty_block))
 
         Variable = pl::user(Name, [](const item_t& item) {
                 State* st = reinterpret_cast<State*>(item.user_data);
-                for (auto it = item.begin; it != item.end; ++it) st->buffer += static_cast<char>(*it);
+                for (auto it = item.begin->m_it; it != item.end->m_it; ++it) st->buffer += static_cast<char>(*it);
                 auto isValid = Keywords.find(st->buffer) == Keywords.end();
                 if (isValid) {
                         if (st->buffer == st->moduleName) {
@@ -98,7 +104,7 @@ YueParser::YueParser() {
 
         LabelName = pl::user(Name, [](const item_t& item) {
                 State* st = reinterpret_cast<State*>(item.user_data);
-                for (auto it = item.begin; it != item.end; ++it) st->buffer += static_cast<char>(*it);
+                for (auto it = item.begin->m_it; it != item.end->m_it; ++it) st->buffer += static_cast<char>(*it);
                 auto isValid = LuaKeywords.find(st->buffer) == LuaKeywords.end();
                 st->buffer.clear();
                 return isValid;
@@ -106,7 +112,7 @@ YueParser::YueParser() {
 
         LuaKeyword = pl::user(Name, [](const item_t& item) {
                 State* st = reinterpret_cast<State*>(item.user_data);
-                for (auto it = item.begin; it != item.end; ++it) st->buffer += static_cast<char>(*it);
+                for (auto it = item.begin->m_it; it != item.end->m_it; ++it) st->buffer += static_cast<char>(*it);
                 auto it = LuaKeywords.find(st->buffer);
                 st->buffer.clear();
                 return it != LuaKeywords.end();
@@ -123,7 +129,7 @@ YueParser::YueParser() {
 
         check_indent = pl::user(Indent, [](const item_t& item) {
                 int indent = 0;
-                for (input_it i = item.begin; i != item.end; ++i) {
+                for (input_it i = item.begin->m_it; i != item.end->m_it; ++i) {
                         switch (*i) {
                                 case ' ': indent++; break;
                                 case '\t': indent += 4; break;
@@ -136,7 +142,7 @@ YueParser::YueParser() {
 
         advance = pl::user(Indent, [](const item_t& item) {
                 int indent = 0;
-                for (input_it i = item.begin; i != item.end; ++i) {
+                for (input_it i = item.begin->m_it; i != item.end->m_it; ++i) {
                         switch (*i) {
                                 case ' ': indent++; break;
                                 case '\t': indent += 4; break;
@@ -154,7 +160,7 @@ YueParser::YueParser() {
 
         push_indent = pl::user(Indent, [](const item_t& item) {
                 int indent = 0;
-                for (input_it i = item.begin; i != item.end; ++i) {
+                for (input_it i = item.begin->m_it; i != item.end->m_it; ++i) {
                         switch (*i) {
                                 case ' ': indent++; break;
                                 case '\t': indent += 4; break;
@@ -232,9 +238,9 @@ YueParser::YueParser() {
 
         WithExp = ExpList >> -Assign;
 
-        With = Space >> key("with") >> -existential_op >> disable_do_chain_arg_table_block(WithExp) >> plain_body_with("do");
-        SwitchCase = Space >> key("when") >> disable_chain(disable_arg_table_block(SwitchList)) >> plain_body_with("then");
-        SwitchElse = Space >> key("else") >> plain_body;
+        With = Space >> key("with") >> -existential_op >> disable_do_chain_arg_table_block(WithExp) >> body_with("do");
+        SwitchCase = Space >> key("when") >> disable_chain(disable_arg_table_block(SwitchList)) >> body_with("then");
+        SwitchElse = Space >> key("else") >> body;
 
         SwitchBlock = *EmptyLine >>
                 Advance >> Seperator >>
@@ -251,24 +257,24 @@ YueParser::YueParser() {
 
         assignment = ExpList >> Assign;
         IfCond = disable_chain(disable_arg_table_block(assignment | Exp));
-        IfElseIf = -(Break >> *EmptyLine >> CheckIndent) >> Space >> key("elseif") >> IfCond >> plain_body_with("then");
-        IfElse = -(Break >> *EmptyLine >> CheckIndent) >> Space >> key("else") >> plain_body;
+        IfElseIf = -(Break >> *EmptyLine >> CheckIndent) >> Space >> key("elseif") >> IfCond >> body_with("then");
+        IfElse = -(Break >> *EmptyLine >> CheckIndent) >> Space >> key("else") >> body;
         IfType = (expr("if") | expr("unless")) >> not_(AlphaNum);
-        If = Space >> IfType >> IfCond >> plain_body_with("then") >> *IfElseIf >> -IfElse;
+        If = Space >> IfType >> IfCond >> opt_body_with("then") >> *IfElseIf >> -IfElse;
 
         WhileType = (expr("while") | expr("until")) >> not_(AlphaNum);
-        While = WhileType >> disable_do_chain_arg_table_block(Exp) >> plain_body_with("do");
+        While = WhileType >> disable_do_chain_arg_table_block(Exp) >> opt_body_with("do");
         Repeat = key("repeat") >> Body >> Break >> *EmptyLine >> CheckIndent >> Space >> key("until") >> Exp;
 
         for_step_value = sym(',') >> Exp;
         for_args = Space >> Variable >> sym('=') >> Exp >> sym(',') >> Exp >> -for_step_value;
 
-        For = key("for") >> disable_do_chain_arg_table_block(for_args) >> plain_body_with("do");
+        For = key("for") >> disable_do_chain_arg_table_block(for_args) >> opt_body_with("do");
 
         for_in = star_exp | ExpList;
 
         ForEach = key("for") >> AssignableNameList >> Space >> key("in") >>
-                disable_do_chain_arg_table_block(for_in) >> plain_body_with("do");
+                disable_do_chain_arg_table_block(for_in) >> opt_body_with("do");
 
         Do = pl::user(Space >> key("do"), [](const item_t& item) {
                 State* st = reinterpret_cast<State*>(item.user_data);
@@ -413,14 +419,14 @@ YueParser::YueParser() {
         lua_string_close = ']' >> *expr('=') >> ']';
 
         LuaStringOpen = pl::user(lua_string_open, [](const item_t& item) {
-                size_t count = std::distance(item.begin, item.end);
+                size_t count = std::distance(item.begin->m_it, item.end->m_it);
                 State* st = reinterpret_cast<State*>(item.user_data);
                 st->stringOpen = count;
                 return true;
         });
 
         LuaStringClose = pl::user(lua_string_close, [](const item_t& item) {
-                size_t count = std::distance(item.begin, item.end);
+                size_t count = std::distance(item.begin->m_it, item.end->m_it);
                 State* st = reinterpret_cast<State*>(item.user_data);
                 return st->stringOpen == count;
         });
@@ -655,7 +661,8 @@ YueParser::YueParser() {
                 Import | While | Repeat | For | ForEach |
                 Return | Local | Global | Export | Macro |
                 MacroInPlace | BreakLoop | Label | Goto | ShortTabAppending |
-                LocalAttrib | Backcall | PipeBody | ExpListAssign
+                LocalAttrib | Backcall | PipeBody | ExpListAssign |
+                statement_appendix >> invalid_empty_block
         ) >> Space >>
         -statement_appendix >> -statement_sep;
 
@@ -699,6 +706,9 @@ ParseInfo YueParser::parse(std::string_view codes, rule& r) {
                         res.exportDefault = state.exportDefault;
                         res.exportMacro = state.exportMacro;
                 }
+        } catch (const ParserError& err) {
+                res.error = res.errorMessage(err.what(), &err.loc);
+                return res;
         } catch (const std::logic_error& err) {
                 res.error = err.what();
                 return res;