More work on variables and parameters

4 files changed, 44 insertions, 1 deletions

diff --git a/src/GCodes/GCodeBuffer/ExpressionParser.cpp b/src/GCodes/GCodeBuffer/ExpressionParser.cpp
index 344810e3..48f5c027 100644
--- a/src/GCodes/GCodeBuffer/ExpressionParser.cpp
+++ b/src/GCodes/GCodeBuffer/ExpressionParser.cpp
@@ -1031,6 +1031,23 @@ ExpressionValue ExpressionParser::ParseIdentifierExpression(bool evaluate, bool
 	// If we are not evaluating then the object expression doesn't have to exist, so don't retrieve it because that might throw an error
 	if (evaluate)
 	{
+		// Check for a parameter, local or global variable
+		if (StringStartsWith(id.c_str(), "param."))
+		{
+			return GetVariableValue(gb.GetVariables(), id.c_str() + strlen("param."), true);
+		}
+
+		if (StringStartsWith(id.c_str(), "global."))
+		{
+			return GetVariableValue(gb.GetVariables(), id.c_str() + strlen("global."), false);
+		}
+
+		if (StringStartsWith(id.c_str(), "user."))
+		{
+			return GetVariableValue(reprap.globalVariables, id.c_str() + strlen("user."), false);
+		}
+
+		// Else assume an object model value
 		ExpressionValue value = reprap.GetObjectValue(context, nullptr, id.c_str());
 		if (context.ObsoleteFieldQueried() && obsoleteField.IsEmpty())
 		{
@@ -1041,6 +1058,18 @@ ExpressionValue ExpressionParser::ParseIdentifierExpression(bool evaluate, bool
 	return ExpressionValue(nullptr);
 }
 
+// Get the value of a variable
+ExpressionValue ExpressionParser::GetVariableValue(VariableSet& vars, const char *name, bool parameter) THROWS(GCodeException)
+{
+	const Variable* var = vars.Lookup(name);
+	if (var != nullptr && (!parameter || var->GetScope() < 0))
+	{
+		return var->GetValue();
+	}
+
+	throw ConstructParseException("Unknown variable");
+}
+
 // Parse a quoted string, given that the current character is double-quote
 // This is almost a copy of InternalGetQuotedString in class StringParser
 ExpressionValue ExpressionParser::ParseQuotedString() THROWS(GCodeException)
diff --git a/src/GCodes/GCodeBuffer/ExpressionParser.h b/src/GCodes/GCodeBuffer/ExpressionParser.h
index f48679fc..3dd5f236 100644
--- a/src/GCodes/GCodeBuffer/ExpressionParser.h
+++ b/src/GCodes/GCodeBuffer/ExpressionParser.h
@@ -13,6 +13,8 @@
 #include <ObjectModel/ObjectModel.h>
 #include <GCodes/GCodeException.h>
 
+class VariableSet;
+
 class ExpressionParser
 {
 public:
@@ -41,6 +43,7 @@ private:
 	ExpressionValue ParseIdentifierExpression(bool evaluate, bool applyLengthOperator) THROWS(GCodeException)
 		pre(readPointer >= 0; isalpha(gb.buffer[readPointer]));
 	ExpressionValue ParseQuotedString() THROWS(GCodeException);
+	ExpressionValue GetVariableValue(VariableSet& vars, const char *name, bool parameter) THROWS(GCodeException);
 
 	void ConvertToFloat(ExpressionValue& val, bool evaluate) const THROWS(GCodeException);
 	void ConvertToBool(ExpressionValue& val, bool evaluate) const THROWS(GCodeException);
diff --git a/src/GCodes/GCodeBuffer/GCodeBuffer.cpp b/src/GCodes/GCodeBuffer/GCodeBuffer.cpp
index 21e6c1f2..1feac192 100644
--- a/src/GCodes/GCodeBuffer/GCodeBuffer.cpp
+++ b/src/GCodes/GCodeBuffer/GCodeBuffer.cpp
@@ -1016,4 +1016,14 @@ void GCodeBuffer::SetParameters(int codeRunning) noexcept
 	PARSER_OPERATION(SetParameters(machineState, codeRunning));
 }
 
+VariableSet& GCodeBuffer::GetVariables() const noexcept
+{
+	GCodeMachineState *mc = machineState;
+	while (mc->localPush && mc->GetPrevious() != nullptr)
+	{
+		mc = mc->GetPrevious();
+	}
+	return mc->variables;
+}
+
 // End
diff --git a/src/GCodes/GCodeBuffer/GCodeBuffer.h b/src/GCodes/GCodeBuffer/GCodeBuffer.h
index 25931cc4..65acf25f 100644
--- a/src/GCodes/GCodeBuffer/GCodeBuffer.h
+++ b/src/GCodes/GCodeBuffer/GCodeBuffer.h
@@ -49,7 +49,7 @@ public:
 	void Init() noexcept;														// Set it up to parse another G-code
 	void Diagnostics(MessageType mtype) noexcept;								// Write some debug info
 
-	bool Put(char c) noexcept SPEED_CRITICAL;								// Add a character to the end
+	bool Put(char c) noexcept SPEED_CRITICAL;									// Add a character to the end
 #if HAS_LINUX_INTERFACE
 	void PutBinary(const uint32_t *data, size_t len) noexcept;					// Add an entire binary G-Code, overwriting any existing content
 #endif
@@ -224,6 +224,7 @@ public:
 	bool WasMotionCommanded() const noexcept { return motionCommanded; }
 
 	void SetParameters(int codeRunning) noexcept;
+	VariableSet& GetVariables() const noexcept;
 
 	Mutex mutex;