Flow control (#1296)

* If else endif is working; nothing else has been tested

* Cleanups

* Loops work

* PRINT, and DEBUG,

* Complain about undefined parameters

* Lots of error messages

* Skip prints inside non-executed IF clauses

* Fixed EXISTS bug with global named parameters

* Fixed WebUI bugs with system parameters

FluidNC/src/Channel.h

@@ -193,6 +193,8 @@ class Channel : public Stream {
 
     size_t lineNumber() { return _line_number; }
 
-    virtual void save() {}
-    virtual void restore() {}
+    virtual void   save() {}
+    virtual void   restore() {}
+    virtual size_t position() { return 0; }
+    virtual void   set_position(size_t pos) {}
 };

FluidNC/src/Error.cpp

@@ -83,4 +83,9 @@ const std::map<Error, const char*> ErrorNames = {
     { Error::ExpressionUnknownOp, "Expression Unknown Operator" },
     { Error::ExpressionArgumentOutOfRange, "Expression Argument Out of Range" },
     { Error::ExpressionSyntaxError, "Expression Syntax Error" },
+    { Error::FlowControlSyntaxError, "Flow Control Syntax Error" },
+    { Error::FlowControlNotExecutingMacro, "Flow Control Not Executing Macro" },
+    { Error::FlowControlOutOfMemory, "Flow Control Out of Memory" },
+    { Error::FlowControlStackOverflow, "Flow Control Stack Overflow" },
+    { Error::ParameterAssignmentFailed, "Parameter Assignment Failed" },
 };

FluidNC/src/Error.h

@@ -88,6 +88,11 @@ enum class Error : uint8_t {
     ExpressionUnknownOp          = 173,
     ExpressionArgumentOutOfRange = 174,
     ExpressionSyntaxError        = 175,
+    FlowControlSyntaxError       = 176,
+    FlowControlNotExecutingMacro = 177,
+    FlowControlOutOfMemory       = 178,
+    FlowControlStackOverflow     = 179,
+    ParameterAssignmentFailed    = 180,
 };
 
 const char* errorString(Error errorNumber);