Dynamic databinding variable expressions

Source/Core/DataExpression.cpp

@@ -103,6 +103,11 @@ struct InstructionData {
 	Variant data;
 };
 
+struct ProgramState {
+	size_t program_length;
+	int stack_size;
+};
+
 namespace Parse {
 	static void Assignment(DataParser& parser);
 	static void Expression(DataParser& parser);
@@ -196,12 +201,6 @@ class DataParser {
 			parse_error = true;
 			Error(CreateString(120, "Internal parser error, inconsistent stack operations. Stack size is %d at parse end.", program_stack_size));
 		}
-		if (!parse_error && !program_states.empty())
-		{
-			parse_error = true;
-			Error(CreateString(140, "Internal parser error, inconsistent state stack operations. State stack size is %d at parse end.",
-				(int)program_states.size()));
-		}
 
 		return !parse_error;
 	}
@@ -255,28 +254,19 @@ class DataParser {
 		program.push_back(InstructionData{Instruction::NumArguments, Variant(int(num_arguments))});
 		program.push_back(InstructionData{instruction, Variant(std::move(name))});
 	}
-	void Variable(const String& expression) { VariableGetSet(expression, false); }
-	void Assign(const String& expression) { VariableGetSet(expression, true); }
+	void StaticVariable(const String& expression) { VariableGetSet(expression, false); }
+	void StaticAssign(const String& expression) { VariableGetSet(expression, true); }
 
-	void PushState() { program_states.push_back(ProgramState{program.size(), program_stack_size, index}); }
+	ProgramState GetProgramState() { return ProgramState{program.size(), program_stack_size}; }
 
-	void PopState()
+	void SetProgramState(const ProgramState& state)
 	{
-		RMLUI_ASSERT(!program_states.empty());
-		auto const& state = program_states.back();
 		RMLUI_ASSERT(state.program_length <= program.size());
 		program.resize(state.program_length);
 		program_stack_size = state.stack_size;
-		program_states.pop_back();
-	}
-
-	void DiscardState()
-	{
-		RMLUI_ASSERT(!program_states.empty());
-		program_states.pop_back();
 	}
 
-	bool Address(const String& name)
+	bool AddVariableAddress(const String& name)
 	{
 		DataAddress address = expression_interface.ParseAddress(name);
 		if (address.empty())
@@ -313,14 +303,6 @@ class DataParser {
 	Program program;
 
 	AddressList variable_addresses;
-
-	struct ProgramState {
-		size_t program_length;
-		int stack_size;
-		size_t index;
-	};
-
-	Vector<ProgramState> program_states;
 };
 
 namespace Parse {
@@ -335,8 +317,9 @@ namespace Parse {
 	static void Term(DataParser& parser);
 	static void Factor(DataParser& parser);
 
-	static String NumberLiteral(DataParser& parser, bool silent = false);
+	static void NumberLiteral(DataParser& parser);
 	static void StringLiteral(DataParser& parser);
+	static String VariableExpression(DataParser& parser, const String& address_prefix);
 	static void VariableOrFunction(DataParser& parser);
 
 	static void Add(DataParser& parser);
@@ -366,7 +349,7 @@ namespace Parse {
 		if (is_alpha || (c >= '0' && c <= '9'))
 			return true;
 
-		for (char valid_char : "_. ")
+		for (char valid_char : "_.")
 		{
 			if (c == valid_char && valid_char != '\0')
 				return true;
@@ -387,24 +370,42 @@ namespace Parse {
 			is_first_character = false;
 		}
 
-		// Right trim spaces in name
-		size_t new_size = String::npos;
-		for (int i = int(name.size()) - 1; i >= 1; i--)
-		{
-			if (name[i] == ' ')
-				new_size = size_t(i);
-			else
-				break;
-		}
-		if (new_size != String::npos)
-			name.resize(new_size);
-
 		if (out_valid_function_name)
 			*out_valid_function_name = (name.find_first_of(". ") == String::npos);
 
 		return name;
 	}
 
+	static String FindNumberLiteral(DataParser& parser)
+	{
+		String str;
+
+		bool first_match = false;
+		bool has_dot = false;
+		char c = parser.Look();
+		if (c == '-')
+		{
+			str += c;
+			c = parser.Next();
+		}
+
+		while ((c >= '0' && c <= '9') || (c == '.' && !has_dot))
+		{
+			first_match = true;
+			str += c;
+			if (c == '.')
+				has_dot = true;
+			c = parser.Next();
+		}
+
+		if (!first_match)
+		{
+			return String();
+		}
+
+		return str;
+	}
+
 	// Parser functions
 	static void Assignment(DataParser& parser)
 	{
@@ -420,12 +421,14 @@ namespace Parse {
 					return;
 				}
 
+				parser.SkipWhitespace();
+
 				const char c = parser.Look();
 				if (c == '=')
 				{
 					parser.Match('=');
 					Expression(parser);
-					parser.Assign(variable_name);
+					parser.StaticAssign(variable_name);
 				}
 				else if (c == '(' || c == ';' || c == '\0')
 				{
@@ -564,9 +567,7 @@ namespace Parse {
 		}
 		else if (c == '-' || (c >= '0' && c <= '9'))
 		{
-			const double number = FromString(NumberLiteral(parser), 0.0);
-
-			parser.Emit(Instruction::Literal, Variant(number));
+			NumberLiteral(parser);
 			parser.SkipWhitespace();
 		}
 		else if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'))
@@ -578,7 +579,7 @@ namespace Parse {
 			parser.Expected("literal, variable name, function name, parenthesis, or '!'");
 	}
 
-	static String NumberLiteral(DataParser& parser, bool silent)
+	static void NumberLiteral(DataParser& parser)
 	{
 		String str;
 
@@ -602,12 +603,13 @@ namespace Parse {
 
 		if (!first_match)
 		{
-			if (!silent)
-				parser.Error(CreateString(100, "Invalid number literal. Expected '0-9' or '.' but found '%c'.", c));
-			return String();
+			parser.Error(CreateString(100, "Invalid number literal. Expected '0-9' or '.' but found '%c'.", c));
+			return;
 		}
 
-		return str;
+		const double number = FromString(str, 0.0);
+
+		parser.Emit(Instruction::Literal, Variant(number));
 	}
 
 	static void StringLiteral(DataParser& parser)
@@ -636,7 +638,7 @@ namespace Parse {
 		parser.Emit(Instruction::Literal, Variant(str));
 	}
 
-	static String VariableExpression(DataParser& parser, String const& address_prefix)
+	static String VariableExpression(DataParser& parser, const String& address_prefix)
 	{
 		if (parser.Look() == '[')
 		{
@@ -645,19 +647,21 @@ namespace Parse {
 
 			prefix.push_back('[');
 
-			parser.PushState();
-			String index = NumberLiteral(parser, true);
+			// Backup program state before trying to parse number inside brackets.
+			// Could turn out to be expression and needs reparsing
+			auto backup_state = parser.GetProgramState();
+
+			String index = FindNumberLiteral(parser);
 			if (!index.empty() && parser.Look() == ']')
 			{
-				parser.DiscardState();
 				parser.Next();
 				prefix.append(index);
 				prefix.push_back(']');
 				return VariableExpression(parser, prefix);
 			}
 			else
 			{
-				parser.PopState();
+				parser.SetProgramState(backup_state);
 
 				parser.Emit(Instruction::Literal, Variant(prefix));
 				parser.Push();
@@ -693,8 +697,6 @@ namespace Parse {
 			}
 			return VariableExpression(parser, address_prefix + next);
 		}
-
-		return address_prefix;
 	}
 
 	static void VariableOrFunction(DataParser& parser)
@@ -723,26 +725,27 @@ namespace Parse {
 		}
 		else if (parser.Look() == '[')
 		{
-			parser.PushState();
+			// Backup program state before trying to parse part inside brackets.
+			// Could turn out to be expression and needs reparsing
+			auto backup_state = parser.GetProgramState();
 
 			String full_address = VariableExpression(parser, name);
 
 			if (!full_address.empty())
 			{
-				parser.PopState();
-				parser.Variable(full_address);
+				parser.SetProgramState(backup_state);
+				parser.StaticVariable(full_address);
 			}
 			else
 			{
 				// add the root of a variable expression as dependency into the address list
-				parser.Address(name);
+				parser.AddVariableAddress(name);
 
-				parser.DiscardState();
 				parser.Emit(Instruction::DynamicVariable, Variant());
 			}
 		}
 		else
-			parser.Variable(name);
+			parser.StaticVariable(name);
 	}
 
 	static void Add(DataParser& parser)
@@ -1115,7 +1118,11 @@ class DataInterpreter {
 		break;
 		case Instruction::CastToInt:
 		{
-			R = R.Get<int>();
+			int tmp;
+			if (!R.GetInto(tmp))
+				return Error("Could not cast value to int.");
+			else
+				R = tmp;
 		}
 		break;
 		default: RMLUI_ERRORMSG("Instruction not implemented."); break;

Tests/Source/UnitTests/DataBinding.cpp

@@ -34,7 +34,6 @@
 #include <cmath>
 #include <doctest.h>
 
-
 using namespace Rml;
 
 namespace {
@@ -559,6 +558,7 @@ TEST_CASE("databinding.dynamic_variables")
 	CHECK(document->QuerySelector("p:nth-child(4)")->GetInnerRML() == "c2");
 
 	document->Close();
+	*globals.i1 = 1;
 
 	TestsShell::ShutdownShell();
 }