fix table matching issue and update doc.

1 files changed, 47 insertions, 25 deletions

diff --git a/src/yuescript/yue_compiler.cpp b/src/yuescript/yue_compiler.cpp
index c68746c..2565878 100755
--- a/src/yuescript/yue_compiler.cpp
+++ b/src/yuescript/yue_compiler.cpp
@@ -56,7 +56,7 @@ using namespace parserlib;
 
 typedef std::list<std::string> str_list;
 
-const std::string_view version = "0.13.3"sv;
+const std::string_view version = "0.13.4"sv;
 const std::string_view extension = "yue"sv;
 
 class YueCompilerImpl {
@@ -1582,12 +1582,22 @@ private:
                                                         added--;
                                                 }
                                                 if (pair.defVal) {
-                                                        auto stmt = toAst<Statement_t>(pair.targetVar + "=nil if "s + pair.targetVar + "==nil", pair.defVal);
-                                                        auto defAssign = stmt->content.as<ExpListAssign_t>();
-                                                        auto assign = defAssign->action.as<Assign_t>();
-                                                        assign->values.clear();
-                                                        assign->values.push_back(pair.defVal);
-                                                        transformStatement(stmt, temp);
+                                                        bool isNil = false;
+                                                        if (auto v1 = singleValueFrom(pair.defVal)) {
+                                                                if (auto v2 = v1->item.as<SimpleValue_t>()) {
+                                                                        if (auto v3 = v2->value.as<const_value_t>()) {
+                                                                                isNil = _parser.toString(v3) == "nil"sv;
+                                                                        }
+                                                                }
+                                                        }
+                                                        if (!isNil) {
+                                                                auto stmt = toAst<Statement_t>(pair.targetVar + "=nil if "s + pair.targetVar + "==nil", pair.defVal);
+                                                                auto defAssign = stmt->content.as<ExpListAssign_t>();
+                                                                auto assign = defAssign->action.as<Assign_t>();
+                                                                assign->values.clear();
+                                                                assign->values.push_back(pair.defVal);
+                                                                transformStatement(stmt, temp);
+                                                        }
                                                 }
                                                 continue;
                                         }
@@ -1709,12 +1719,22 @@ private:
                                 }
                                 for (const auto& item : destruct.items) {
                                         if (item.defVal) {
-                                                auto stmt = toAst<Statement_t>(item.targetVar + "=nil if "s + item.targetVar + "==nil", item.defVal);
-                                                auto defAssign = stmt->content.as<ExpListAssign_t>();
-                                                auto assign = defAssign->action.as<Assign_t>();
-                                                assign->values.clear();
-                                                assign->values.push_back(item.defVal);
-                                                transformStatement(stmt, temp);
+                                                bool isNil = false;
+                                                if (auto v1 = singleValueFrom(item.defVal)) {
+                                                        if (auto v2 = v1->item.as<SimpleValue_t>()) {
+                                                                if (auto v3 = v2->value.as<const_value_t>()) {
+                                                                        isNil = _parser.toString(v3) == "nil"sv;
+                                                                }
+                                                        }
+                                                }
+                                                if (!isNil) {
+                                                        auto stmt = toAst<Statement_t>(item.targetVar + "=nil if "s + item.targetVar + "==nil", item.defVal);
+                                                        auto defAssign = stmt->content.as<ExpListAssign_t>();
+                                                        auto assign = defAssign->action.as<Assign_t>();
+                                                        assign->values.clear();
+                                                        assign->values.push_back(item.defVal);
+                                                        transformStatement(stmt, temp);
+                                                }
                                         }
                                 }
                                 for (const auto& item : leftPairs) {
@@ -7160,32 +7180,34 @@ private:
                                 auto assignment = assignmentFrom(static_cast<Exp_t*>(branch->valueList->exprs.front()), toAst<Exp_t>(objVar, branch), branch);
                                 auto info = extractDestructureInfo(assignment, true, false);
                                 transformAssignment(assignment, temp, true);
-                                temp.push_back(indent() + "if"s);
-                                bool firstItem = true;
+                                str_list conds;
                                 for (const auto& destruct : info.first) {
                                         for (const auto& item : destruct.items) {
-                                                str_list tmp;
-                                                transformExp(item.target, tmp, ExpUsage::Closure);
-                                                temp.back().append((firstItem ? " " : " and "s) + tmp.back() + " ~= nil"s);
-                                                if (firstItem) firstItem = false;
+                                                if (!item.defVal) {
+                                                        transformExp(item.target, conds, ExpUsage::Closure);
+                                                        conds.back().append(" ~= nil"s);
+                                                }
                                         }
                                 }
-                                temp.back().append(" then"s + nll(branch));
-                                pushScope();
-                                transform_plain_body(branch->body, temp, usage, assignList);
+                                if (!conds.empty()) {
+                                        temp.push_back(indent() + "if "s + join(conds, " and "sv) + " then"s + nll(branch));
+                                        pushScope();
+                                }
                                 if (!lastBranch) {
                                         temp.push_back(indent() + matchVar + " = true"s + nll(branch));
                                 }
-                                popScope();
-                                if (!lastBranch) {
+                                transform_plain_body(branch->body, temp, usage, assignList);
+                                if (!conds.empty()) {
+                                        popScope();
                                         temp.push_back(indent() + "end"s + nll(branch));
+                                }
+                                if (!lastBranch) {
                                         popScope();
                                         temp.push_back(indent() + "end"s + nll(branch));
                                         temp.push_back(indent() + "if not "s + matchVar + " then"s + nll(branch));
                                         pushScope();
                                         addScope++;
                                 } else {
-                                        temp.push_back(indent() + "end"s + nll(branch));
                                         popScope();
                                 }
                                 firstBranch = true;