Added more reversed index support for slice. [skip CI]

1 files changed, 86 insertions, 5 deletions

diff --git a/src/yuescript/yue_compiler.cpp b/src/yuescript/yue_compiler.cpp
index cbf976f..9f5a41e 100644
--- a/src/yuescript/yue_compiler.cpp
+++ b/src/yuescript/yue_compiler.cpp
@@ -8180,6 +8180,11 @@ private:
         }
 
         bool transformForEachHead(AssignableNameList_t* nameList, ast_node* loopTarget, str_list& out, bool inClosure) {
+                enum class NumState {
+                        Unknown,
+                        Positive,
+                        Negtive
+                };
                 auto x = nameList;
                 str_list temp;
                 str_list vars;
@@ -8246,15 +8251,35 @@ private:
                                 for (auto item : chainList) {
                                         chain->items.push_back(item);
                                 }
-                                std::string startValue("1"sv);
+                                std::string startValue;
+                                NumState startStatus = NumState::Unknown;
                                 if (auto exp = slice->startValue.as<Exp_t>()) {
                                         transformExp(exp, temp, ExpUsage::Closure);
+                                        if (temp.back().at(0) == '-') {
+                                                if (_parser.match<Num_t>(temp.back().substr(1))) {
+                                                        startStatus = NumState::Negtive;
+                                                }
+                                        } else {
+                                                if (_parser.match<Num_t>(temp.back())) {
+                                                        startStatus = NumState::Positive;
+                                                }
+                                        }
                                         startValue = std::move(temp.back());
                                         temp.pop_back();
                                 }
                                 std::string stopValue;
+                                NumState stopStatus = NumState::Unknown;
                                 if (auto exp = slice->stopValue.as<Exp_t>()) {
                                         transformExp(exp, temp, ExpUsage::Closure);
+                                        if (temp.back().at(0) == '-') {
+                                                if (_parser.match<Num_t>(temp.back().substr(1))) {
+                                                        stopStatus = NumState::Negtive;
+                                                }
+                                        } else {
+                                                if (_parser.match<Num_t>(temp.back())) {
+                                                        stopStatus = NumState::Positive;
+                                                }
+                                        }
                                         stopValue = std::move(temp.back());
                                         temp.pop_back();
                                 }
@@ -8276,8 +8301,33 @@ private:
                                         transformChainValue(chain, temp, ExpUsage::Closure);
                                         _buf << prefix << indent() << "local "sv << listVar << " = "sv << temp.back() << nll(nameList);
                                 }
+                                if (startValue.empty()) {
+                                        startValue = "1"s;
+                                        startStatus = NumState::Positive;
+                                }
+                                std::string minVar;
+                                if (startStatus != NumState::Positive) {
+                                        std::string prefix;
+                                        if (!extraScope && !inClosure && needScope) {
+                                                extraScope = true;
+                                                prefix = indent() + "do"s + nll(x);
+                                                pushScope();
+                                        }
+                                        minVar = getUnusedName("_min_"sv);
+                                        varBefore.push_back(minVar);
+                                        if (startStatus == NumState::Negtive) {
+                                                _buf << prefix << indent() << "local "sv << minVar << " = "sv << "#"sv << listVar << " + "sv << startValue << " + 1"sv << nll(nameList);
+                                        } else {
+                                                _buf << prefix << indent() << "local "sv << minVar << " = "sv << startValue << nll(nameList);
+                                        }
+                                }
+                                bool defaultStop = false;
+                                if (stopValue.empty()) {
+                                        stopValue = "#"s + listVar;
+                                        defaultStop = true;
+                                }
                                 std::string maxVar;
-                                if (!stopValue.empty()) {
+                                if (stopStatus != NumState::Positive) {
                                         std::string prefix;
                                         if (!extraScope && !inClosure && needScope) {
                                                 extraScope = true;
@@ -8286,14 +8336,45 @@ private:
                                         }
                                         maxVar = getUnusedName("_max_"sv);
                                         varBefore.push_back(maxVar);
-                                        _buf << prefix << indent() << "local "sv << maxVar << " = "sv << stopValue << nll(nameList);
+                                        if (stopStatus == NumState::Negtive) {
+                                                _buf << indent() << "local "sv << maxVar << " = "sv << "#"sv << listVar << " + "sv << stopValue << " + 1"sv << nll(nameList);
+                                        } else {
+                                                _buf << prefix << indent() << "local "sv << maxVar << " = "sv << stopValue << nll(nameList);
+                                        }
+                                }
+                                if (startStatus == NumState::Unknown) {
+                                        _buf << indent() << minVar << " = "sv << minVar << " < 0 and #"sv << listVar << " + "sv << minVar << " + 1 or "sv << minVar << nll(nameList);
+                                }
+                                if (!defaultStop && stopStatus == NumState::Unknown) {
+                                        _buf << indent() << maxVar << " = "sv << maxVar << " < 0 and #"sv << listVar << " + "sv << maxVar << " + 1 or "sv << maxVar << nll(nameList);
                                 }
                                 _buf << indent() << "for "sv << indexVar << " = "sv;
-                                _buf << startValue << ", "sv;
+                                if (startValue.empty()) {
+                                        _buf << "1"sv;
+                                } else {
+                                        switch (startStatus) {
+                                                case NumState::Unknown:
+                                                case NumState::Negtive:
+                                                        _buf << minVar;
+                                                        break;
+                                                case NumState::Positive:
+                                                        _buf << startValue;
+                                                        break;
+                                        }
+                                }
+                                _buf << ", "sv;
                                 if (stopValue.empty()) {
                                         _buf << "#"sv << listVar;
                                 } else {
-                                        _buf << maxVar << " < 0 and #"sv << listVar << " + "sv << maxVar << " + 1 or "sv << maxVar;
+                                        switch (stopStatus) {
+                                                case NumState::Unknown:
+                                                case NumState::Negtive:
+                                                        _buf << maxVar;
+                                                        break;
+                                                case NumState::Positive:
+                                                        _buf << stopValue;
+                                                        break;
+                                        }
                                 }
                                 if (!stepValue.empty()) {
                                         _buf << ", "sv << stepValue;