fix issue #126 by reserving comments before statements

8 files changed, 37 insertions, 7 deletions

diff --git a/README.md b/README.md
index 69baa6e..78489c6 100644
--- a/README.md
+++ b/README.md
@@ -95,6 +95,7 @@ Usage: yue [options|files|directories] ...
    -b       Dump compile time (doesn't write output)
    -g       Dump global variables used in NAME LINE COLUMN
    -l       Write line numbers from source codes
+   -c       Reserve comments before statement from source codes
    -w path  Watch changes and compile every file under directory
    -v       Print version
    --       Read from standard in, print to standard out
diff --git a/src/yue.cpp b/src/yue.cpp
index 7adde70..0b13688 100644
--- a/src/yue.cpp
+++ b/src/yue.cpp
@@ -254,6 +254,7 @@ int main(int narg, const char** args) {
                 "   -b       Dump compile time (doesn't write output)\n"
                 "   -g       Dump global variables used in NAME LINE COLUMN\n"
                 "   -l       Write line numbers from source codes\n"
+                "   -c       Reserve comments before statement from source codes\n"
 #ifndef YUE_NO_WATCHER
                 "   -w path  Watch changes and compile every file under directory\n"
 #endif // YUE_NO_WATCHER
@@ -526,6 +527,8 @@ int main(int narg, const char** args) {
                         config.useSpaceOverTab = true;
                 } else if (arg == "-l"sv) {
                         config.reserveLineNumber = true;
+                } else if (arg == "-c"sv) {
+                        config.reserveComment = true;
                 } else if (arg == "-p"sv) {
                         writeToFile = false;
                 } else if (arg == "-g"sv) {
diff --git a/src/yuescript/yue_ast.h b/src/yuescript/yue_ast.h
index b265ebc..47ddb0b 100644
--- a/src/yuescript/yue_ast.h
+++ b/src/yuescript/yue_ast.h
@@ -840,7 +840,12 @@ AST_END(StatementSep, "statement_sep"sv)
 AST_LEAF(YueLineComment)
 AST_END(YueLineComment, "comment"sv)
 
-AST_LEAF(YueMultilineComment)
+AST_LEAF(MultilineCommentInner)
+AST_END(MultilineCommentInner, "comment"sv)
+
+AST_NODE(YueMultilineComment)
+        ast_ptr<true, MultilineCommentInner_t> inner;
+        AST_MEMBER(YueMultilineComment, &inner)
 AST_END(YueMultilineComment, "comment"sv)
 
 AST_NODE(ChainAssign)
diff --git a/src/yuescript/yue_compiler.cpp b/src/yuescript/yue_compiler.cpp
index 0cf643f..52ed005 100644
--- a/src/yuescript/yue_compiler.cpp
+++ b/src/yuescript/yue_compiler.cpp
@@ -73,7 +73,7 @@ static std::unordered_set<std::string> Metamethods = {
         "close"s // Lua 5.4
 };
 
-const std::string_view version = "0.15.26"sv;
+const std::string_view version = "0.15.27"sv;
 const std::string_view extension = "yue"sv;
 
 class YueCompilerImpl {
@@ -1160,6 +1160,22 @@ private:
 
         void transformStatement(Statement_t* statement, str_list& out) {
                 auto x = statement;
+                if (_config.reserveComment && !x->comments.empty()) {
+                        for (ast_node* node : x->comments.objects()) {
+                                switch (node->getId()) {
+                                        case id<YueLineComment_t>(): {
+                                                auto comment = ast_cast<YueLineComment_t>(node);
+                                                out.push_back(indent() + "--"s + _parser.toString(comment) + '\n');
+                                                break;
+                                        }
+                                        case id<YueMultilineComment_t>(): {
+                                                auto comment = ast_cast<YueMultilineComment_t>(node);
+                                                out.push_back(indent() + _parser.toString(comment) + '\n');
+                                                break;
+                                        }
+                                }
+                        }
+                }
                 if (statement->appendix) {
                         if (auto assignment = assignmentFrom(statement)) {
                                 auto preDefine = getPreDefineLine(assignment);
diff --git a/src/yuescript/yue_compiler.h b/src/yuescript/yue_compiler.h
index c7a0e1b..a5d33cc 100644
--- a/src/yuescript/yue_compiler.h
+++ b/src/yuescript/yue_compiler.h
@@ -29,6 +29,8 @@ struct YueConfig {
         bool implicitReturnRoot = true;
         bool reserveLineNumber = true;
         bool useSpaceOverTab = false;
+        bool reserveComment = false;
+
         bool exporting = false;
         bool profiling = false;
         int lineOffset = 0;
diff --git a/src/yuescript/yue_parser.cpp b/src/yuescript/yue_parser.cpp
index e70c4a0..78e6e52 100644
--- a/src/yuescript/yue_parser.cpp
+++ b/src/yuescript/yue_parser.cpp
@@ -798,12 +798,12 @@ YueParser::YueParser() {
 
         YueLineComment = *(not_(set("\r\n")) >> any_char);
         yue_line_comment = "--" >> YueLineComment >> and_(stop);
-        YueMultilineComment = multi_line_content;
-        yue_multiline_comment = multi_line_open >> YueMultilineComment >> multi_line_close;
+        MultilineCommentInner = multi_line_content;
+        YueMultilineComment = multi_line_open >> MultilineCommentInner >> multi_line_close;
         yue_comment = check_indent >> (
                 (
-                        yue_multiline_comment >>
-                        *(set(" \t") | yue_multiline_comment) >>
+                        YueMultilineComment >>
+                        *(set(" \t") | YueMultilineComment) >>
                         -yue_line_comment
                 ) | yue_line_comment
         ) >> and_(line_break);
diff --git a/src/yuescript/yue_parser.h b/src/yuescript/yue_parser.h
index 8e7f555..cce6741 100644
--- a/src/yuescript/yue_parser.h
+++ b/src/yuescript/yue_parser.h
@@ -245,7 +245,6 @@ private:
         NONE_AST_RULE(empty_line_break);
         NONE_AST_RULE(yue_comment);
         NONE_AST_RULE(yue_line_comment);
-        NONE_AST_RULE(yue_multiline_comment);
         NONE_AST_RULE(line);
         NONE_AST_RULE(shebang);
 
@@ -389,6 +388,7 @@ private:
         AST_RULE(StatementSep)
         AST_RULE(Statement)
         AST_RULE(YueLineComment)
+        AST_RULE(MultilineCommentInner)
         AST_RULE(YueMultilineComment)
         AST_RULE(ChainAssign)
         AST_RULE(Body)
diff --git a/src/yuescript/yuescript.cpp b/src/yuescript/yuescript.cpp
index ed09aaa..3a17fa8 100644
--- a/src/yuescript/yuescript.cpp
+++ b/src/yuescript/yuescript.cpp
@@ -196,6 +196,9 @@ static int yuetoast(lua_State* L) {
                         auto& current = stack.top();
                         int continuation = current.continuation;
                         auto node = current.node;
+                        if (auto comment = yue::ast_cast<yue::YueMultilineComment_t>(node)) {
+                                node = comment->inner.get();
+                        }
                         switch (continuation) {
                                 case 0: {
                                         if (!current.children) {