cmArgumentParser: Move parser state into dedicated struct

Source/cmArgumentParser.cxx

@@ -56,8 +56,8 @@ auto PositionActionMap::Find(std::size_t pos) const -> const_iterator
 void Instance::Bind(std::function<Continue(cm::string_view)> f,
                     ExpectAtLeast expect)
 {
-  this->KeywordValueFunc = std::move(f);
-  this->KeywordValuesExpected = expect.Count;
+  this->GetState().KeywordValueFunc = std::move(f);
+  this->GetState().KeywordValuesExpected = expect.Count;
 }
 
 void Instance::Bind(bool& val)
@@ -81,7 +81,7 @@ void Instance::Bind(NonEmpty<std::string>& val)
   this->Bind(
     [this, &val](cm::string_view arg) -> Continue {
       if (arg.empty() && this->ParseResults) {
-        this->ParseResults->AddKeywordError(this->Keyword,
+        this->ParseResults->AddKeywordError(this->GetState().Keyword,
                                             "  empty string not allowed\n");
       }
       val = std::string(arg);
@@ -132,48 +132,50 @@ void Instance::Bind(std::vector<std::vector<std::string>>& multiVal)
     ExpectAtLeast{ 0 });
 }
 
-void Instance::Consume(std::size_t pos, cm::string_view arg)
+void Instance::Consume(cm::string_view arg)
 {
-  auto const it = this->Bindings.Keywords.Find(arg);
-  if (it != this->Bindings.Keywords.end()) {
+  ParserState& state = this->GetState();
+
+  auto const it = state.Bindings.Keywords.Find(arg);
+  if (it != state.Bindings.Keywords.end()) {
     this->FinishKeyword();
-    this->Keyword = it->first;
-    this->KeywordValuesSeen = 0;
-    this->DoneWithPositional = true;
-    if (this->Bindings.ParsedKeyword) {
-      this->Bindings.ParsedKeyword(*this, it->first);
+    state.Keyword = it->first;
+    state.KeywordValuesSeen = 0;
+    state.DoneWithPositional = true;
+    if (state.Bindings.ParsedKeyword) {
+      state.Bindings.ParsedKeyword(*this, it->first);
     }
     it->second(*this);
     return;
   }
 
-  if (!this->DoneWithPositional) {
-    auto const pit = this->Bindings.Positions.Find(pos);
-    if (pit != this->Bindings.Positions.end()) {
-      pit->second(*this, pos, arg);
+  if (!state.DoneWithPositional) {
+    auto const pit = state.Bindings.Positions.Find(state.Pos);
+    if (pit != state.Bindings.Positions.end()) {
+      pit->second(*this, state.Pos, arg);
       return;
     }
 
-    if (this->Bindings.TrailingArgs) {
-      this->Keyword = ""_s;
-      this->KeywordValuesSeen = 0;
-      this->DoneWithPositional = true;
-      this->Bindings.TrailingArgs(*this);
-      if (!this->KeywordValueFunc) {
+    if (state.Bindings.TrailingArgs) {
+      state.Keyword = ""_s;
+      state.KeywordValuesSeen = 0;
+      state.DoneWithPositional = true;
+      state.Bindings.TrailingArgs(*this);
+      if (!state.KeywordValueFunc) {
         return;
       }
     }
   }
 
-  if (this->KeywordValueFunc) {
-    switch (this->KeywordValueFunc(arg)) {
+  if (state.KeywordValueFunc) {
+    switch (state.KeywordValueFunc(arg)) {
       case Continue::Yes:
         break;
       case Continue::No:
-        this->KeywordValueFunc = nullptr;
+        state.KeywordValueFunc = nullptr;
         break;
     }
-    ++this->KeywordValuesSeen;
+    ++state.KeywordValuesSeen;
     return;
   }
 
@@ -184,16 +186,18 @@ void Instance::Consume(std::size_t pos, cm::string_view arg)
 
 void Instance::FinishKeyword()
 {
-  if (!this->DoneWithPositional) {
+  ParserState& state = this->GetState();
+
+  if (state.DoneWithPositional) {
     return;
   }
-  if (this->KeywordValuesSeen < this->KeywordValuesExpected) {
+  if (state.KeywordValuesSeen < state.KeywordValuesExpected) {
     if (this->ParseResults) {
-      this->ParseResults->AddKeywordError(this->Keyword,
+      this->ParseResults->AddKeywordError(state.Keyword,
                                           "  missing required value\n");
     }
-    if (this->Bindings.KeywordMissingValue) {
-      this->Bindings.KeywordMissingValue(*this, this->Keyword);
+    if (state.Bindings.KeywordMissingValue) {
+      state.Bindings.KeywordMissingValue(*this, state.Keyword);
     }
   }
 }

Source/cmArgumentParser.h

@@ -165,18 +165,40 @@ public:
   }
 };
 
+class ParserState
+{
+public:
+  cm::string_view Keyword;
+  std::size_t Pos = 0;
+  std::size_t KeywordValuesSeen = 0;
+  std::size_t KeywordValuesExpected = 0;
+  std::function<Continue(cm::string_view)> KeywordValueFunc = nullptr;
+
+  ActionMap const& Bindings;
+  void* Result = nullptr;
+  bool DoneWithPositional = false;
+
+  ParserState(ActionMap const& bindings, void* result)
+    : Bindings(bindings)
+    , Result(result)
+  {
+  }
+};
+
 class Instance
 {
 public:
   Instance(ActionMap const& bindings, ParseResult* parseResult,
            std::vector<std::string>* unparsedArguments, void* result = nullptr)
-    : Bindings(bindings)
+
+    : ParseState(bindings, result)
     , ParseResults(parseResult)
     , UnparsedArguments(unparsedArguments)
-    , Result(result)
   {
   }
 
+  ParserState& GetState() { return ParseState; }
+
   void Bind(std::function<Continue(cm::string_view)> f, ExpectAtLeast expect);
   void Bind(bool& val);
   void Bind(std::string& val);
@@ -219,25 +241,22 @@ public:
   template <typename Range>
   void Parse(Range const& args, std::size_t pos = 0)
   {
-    for (cm::string_view arg : args) {
-      this->Consume(pos++, arg);
+    GetState().Pos = pos;
+
+    for (cm::string_view const arg : args) {
+      this->Consume(arg);
+      GetState().Pos++;
     }
+
     this->FinishKeyword();
   }
 
 private:
-  ActionMap const& Bindings;
+  ParserState ParseState;
   ParseResult* ParseResults = nullptr;
   std::vector<std::string>* UnparsedArguments = nullptr;
-  void* Result = nullptr;
 
-  cm::string_view Keyword;
-  std::size_t KeywordValuesSeen = 0;
-  std::size_t KeywordValuesExpected = 0;
-  std::function<Continue(cm::string_view)> KeywordValueFunc;
-  bool DoneWithPositional = false;
-
-  void Consume(std::size_t pos, cm::string_view arg);
+  void Consume(cm::string_view arg);
   void FinishKeyword();
 
   template <typename Result>
@@ -259,7 +278,7 @@ public:
   cmArgumentParser& Bind(cm::static_string_view name, T member)
   {
     this->Base::Bind(name, [member](Instance& instance) {
-      instance.Bind(static_cast<Result*>(instance.Result)->*member);
+      instance.Bind(static_cast<Result*>(instance.GetState().Result)->*member);
     });
     return *this;
   }
@@ -269,7 +288,7 @@ public:
                                     T Result::*member, U Result::*context)
   {
     this->Base::Bind(name, [member, context](Instance& instance) {
-      auto* result = static_cast<Result*>(instance.Result);
+      auto* result = static_cast<Result*>(instance.GetState().Result);
       instance.Bind(result->*member, result->*context);
     });
     return *this;
@@ -280,7 +299,7 @@ public:
                          ExpectAtLeast expect = { 1 })
   {
     this->Base::Bind(name, [member, expect](Instance& instance) {
-      Result* result = static_cast<Result*>(instance.Result);
+      Result* result = static_cast<Result*>(instance.GetState().Result);
       instance.Bind(
         [result, member](cm::string_view arg) -> Continue {
           return (result->*member)(arg);
@@ -296,8 +315,8 @@ public:
                          ExpectAtLeast expect = { 1 })
   {
     this->Base::Bind(name, [member, expect](Instance& instance) {
-      Result* result = static_cast<Result*>(instance.Result);
-      cm::string_view keyword = instance.Keyword;
+      Result* result = static_cast<Result*>(instance.GetState().Result);
+      cm::string_view keyword = instance.GetState().Keyword;
       instance.Bind(
         [result, member, keyword](cm::string_view arg) -> Continue {
           return (result->*member)(keyword, arg);
@@ -312,7 +331,7 @@ public:
                          ExpectAtLeast expect = { 1 })
   {
     this->Base::Bind(name, [f, expect](Instance& instance) {
-      Result* result = static_cast<Result*>(instance.Result);
+      Result* result = static_cast<Result*>(instance.GetState().Result);
       instance.Bind(
         [result, &f](cm::string_view arg) -> Continue {
           return f(*result, arg);
@@ -328,8 +347,8 @@ public:
     ExpectAtLeast expect = { 1 })
   {
     this->Base::Bind(name, [f, expect](Instance& instance) {
-      Result* result = static_cast<Result*>(instance.Result);
-      cm::string_view keyword = instance.Keyword;
+      Result* result = static_cast<Result*>(instance.GetState().Result);
+      cm::string_view keyword = instance.GetState().Keyword;
       instance.Bind(
         [result, keyword, &f](cm::string_view arg) -> Continue {
           return f(*result, keyword, arg);
@@ -345,7 +364,7 @@ public:
     this->Base::Bind(
       position,
       [member](Instance& instance, std::size_t, cm::string_view arg) {
-        Result* result = static_cast<Result*>(instance.Result);
+        Result* result = static_cast<Result*>(instance.GetState().Result);
         result->*member = arg;
       });
     return *this;
@@ -356,7 +375,8 @@ public:
   {
     this->Base::BindParsedKeyword(
       [member](Instance& instance, cm::string_view arg) {
-        (static_cast<Result*>(instance.Result)->*member).emplace_back(arg);
+        (static_cast<Result*>(instance.GetState().Result)->*member)
+          .emplace_back(arg);
       });
     return *this;
   }
@@ -368,7 +388,7 @@ public:
   cmArgumentParser& BindTrailingArgs(T member)
   {
     this->Base::BindTrailingArgs([member](Instance& instance) {
-      instance.Bind(static_cast<Result*>(instance.Result)->*member);
+      instance.Bind(static_cast<Result*>(instance.GetState().Result)->*member);
     });
     return *this;
   }
@@ -429,7 +449,7 @@ public:
     ExpectAtLeast expect = { 1 })
   {
     this->Base::Bind(name, [f, expect](Instance& instance) {
-      cm::string_view keyword = instance.Keyword;
+      cm::string_view keyword = instance.GetState().Keyword;
       instance.Bind(
         [keyword, &f](cm::string_view arg) -> Continue {
           return f(keyword, arg);