From 514b9f97febe8920a78d6078b092fe84b859a963 Mon Sep 17 00:00:00 2001
From: Li Jin <dragon-fly@qq.com>
Date: Thu, 7 Dec 2023 23:49:48 +0800
Subject: changed the if-assignment syntax to prevent some errors.

---
 src/yuescript/yue_ast.h        |  7 ++++---
 src/yuescript/yue_compiler.cpp | 23 +++++++++++++----------
 src/yuescript/yue_parser.cpp   |  9 +++++++--
 src/yuescript/yue_parser.h     |  1 +
 4 files changed, 25 insertions(+), 15 deletions(-)

(limited to 'src')

diff --git a/src/yuescript/yue_ast.h b/src/yuescript/yue_ast.h
index fa47559..6b2b7f8 100644
--- a/src/yuescript/yue_ast.h
+++ b/src/yuescript/yue_ast.h
@@ -302,14 +302,15 @@ AST_NODE(Switch)
 AST_END(Switch, "switch"sv)
 
 AST_NODE(Assignment)
-	ast_ptr<true, ExpList_t> expList;
+	ast_ptr<false, ExpList_t> expList;
 	ast_ptr<true, Assign_t> assign;
 	AST_MEMBER(Assignment, &expList, &assign)
 AST_END(Assignment, "assignment"sv)
 
 AST_NODE(IfCond)
-	ast_sel<true, Exp_t, Assignment_t> condition;
-	AST_MEMBER(IfCond, &condition)
+	ast_ptr<true, Exp_t> condition;
+	ast_ptr<false, Assignment_t> assignment;
+	AST_MEMBER(IfCond, &condition, &assignment)
 AST_END(IfCond, "if_cond"sv)
 
 AST_LEAF(IfType)
diff --git a/src/yuescript/yue_compiler.cpp b/src/yuescript/yue_compiler.cpp
index 69a028f..d37f911 100644
--- a/src/yuescript/yue_compiler.cpp
+++ b/src/yuescript/yue_compiler.cpp
@@ -75,7 +75,7 @@ static std::unordered_set<std::string> Metamethods = {
 	"close"s // Lua 5.4
 };
 
-const std::string_view version = "0.20.7"sv;
+const std::string_view version = "0.21.0"sv;
 const std::string_view extension = "yue"sv;
 
 class CompileError : public std::logic_error {
@@ -3088,7 +3088,7 @@ private:
 		for (auto it = nodes.rbegin(); it != nodes.rend(); ++it) {
 			ns.push_back(*it);
 			if (auto cond = ast_cast<IfCond_t>(*it)) {
-				if (*it != nodes.front() && cond->condition.is<Assignment_t>()) {
+				if (*it != nodes.front() && cond->assignment) {
 					auto x = *it;
 					auto newIf = x->new_ptr<If_t>();
 					newIf->type.set(toAst<IfType_t>("if"sv, x));
@@ -3142,11 +3142,12 @@ private:
 				default: YUEE("AST node mismatch", node); break;
 			}
 		}
-		auto asmt = ifCondPairs.front().first->condition.as<Assignment_t>();
+		auto firstIfCond = ifCondPairs.front().first;
+		auto asmt = firstIfCond->assignment.get();
 		bool storingValue = false;
 		ast_ptr<false, ExpListAssign_t> extraAssignment;
 		if (asmt) {
-			ast_ptr<false, ast_node> exp = asmt->expList->exprs.front();
+			auto exp = firstIfCond->condition.get();
 			auto x = exp;
 			auto var = singleVariableFrom(exp, false);
 			if (var.empty() || isGlobal(var)) {
@@ -3164,11 +3165,12 @@ private:
 						temp.push_back(indent() + "do"s + nll(asmt));
 						pushScope();
 					}
-					asmt->expList->exprs.pop_front();
 					auto expList = toAst<ExpList_t>(desVar, x);
 					auto assignment = x->new_ptr<ExpListAssign_t>();
-					for (auto expr : asmt->expList->exprs.objects()) {
-						expList->exprs.push_back(expr);
+					if (asmt->expList) {
+						for (auto expr : asmt->expList->exprs.objects()) {
+							expList->exprs.push_back(expr);
+						}
 					}
 					assignment->expList.set(expList);
 					assignment->action.set(asmt->assign);
@@ -3196,9 +3198,10 @@ private:
 				}
 				auto expList = x->new_ptr<ExpList_t>();
 				expList->exprs.push_back(exp);
-				asmt->expList->exprs.pop_front();
-				for (auto expr : asmt->expList->exprs.objects()) {
-					expList->exprs.push_back(expr);
+				if (asmt->expList) {
+					for (auto expr : asmt->expList->exprs.objects()) {
+						expList->exprs.push_back(expr);
+					}
 				}
 				auto assignment = x->new_ptr<ExpListAssign_t>();
 				assignment->expList.set(expList);
diff --git a/src/yuescript/yue_parser.cpp b/src/yuescript/yue_parser.cpp
index 2206686..5b97a25 100644
--- a/src/yuescript/yue_parser.cpp
+++ b/src/yuescript/yue_parser.cpp
@@ -114,6 +114,11 @@ YueParser::YueParser() {
 		return false;
 	});
 
+	if_assignment_syntax_error = pl::user(true_(), [](const item_t& item) {
+		throw ParserError("use := for if-assignment expression"sv, item.begin);
+		return false;
+	});
+
 	#define ensure(patt, finally) ((patt) >> (finally) | (finally) >> cut)
 
 	#define key(str) (expr(str) >> not_alpha_num)
@@ -369,8 +374,8 @@ YueParser::YueParser() {
 			+space_break >> advance_match >> space >> SwitchCase >> switch_block >> pop_indent
 		) >> switch_block;
 
-	Assignment = ExpList >> space >> Assign;
-	IfCond = disable_chain_rule(disable_arg_table_block_rule(Assignment | Exp));
+	Assignment = -(',' >> space >> ExpList >> space) >> (':' >> Assign | and_('=') >> if_assignment_syntax_error);
+	IfCond = disable_chain_rule(disable_arg_table_block_rule(Exp >> -(space >> Assignment)));
 	if_else_if = -(line_break >> *space_break >> check_indent_match) >> space >> key("elseif") >> space >> IfCond >> space >> body_with("then");
 	if_else = -(line_break >> *space_break >> check_indent_match) >> space >> key("else") >> space >> body;
 	IfType = (expr("if") | "unless") >> not_alpha_num;
diff --git a/src/yuescript/yue_parser.h b/src/yuescript/yue_parser.h
index 16b57b2..c3d5d7d 100644
--- a/src/yuescript/yue_parser.h
+++ b/src/yuescript/yue_parser.h
@@ -141,6 +141,7 @@ private:
 	NONE_AST_RULE(invalid_interpolation_error);
 	NONE_AST_RULE(confusing_unary_not_error);
 	NONE_AST_RULE(table_key_pair_error);
+	NONE_AST_RULE(if_assignment_syntax_error);
 
 	NONE_AST_RULE(inc_exp_level);
 	NONE_AST_RULE(dec_exp_level);
-- 
cgit v1.2.3-55-g6feb