// IsConstOrVar - Checkes whether a specified word is a constant or a variable
// Input: Atom - the name of the atom
// Output: Returns true if the specified word is a constant or a variable
private bool IsConstOrVar(string Atom)
{
bool bConstOrVar = false;
// Search constant name space
for (int i = 0; i < GlobalConstants.Count; i++)
{
ForthConstant fc = (ForthConstant)GlobalConstants[i];
if (fc.Name.ToUpper() == Atom.ToUpper())
{
bConstOrVar = true;
}
}
// Search variable name space
for (int i = 0; i < GlobalVariables.Count; i++)
{
ForthVariable fv = (ForthVariable)GlobalVariables[i];
if (fv.Name.ToUpper() == Atom.ToUpper())
{
bConstOrVar = true;
}
}
return(bConstOrVar);
}
// DoAnalysis - Builds up the word, constant and variable lists
// Input: None
// Output: None (Globally changes GlobalVariables, GlobalConstants, LocalVariables, Words)
private void DoAnalysis()
{
ForthAtom Atom, NextAtom;
ForthWord WordDef = null; // Holds the definition of a word
string temp;
int noIFs = 0; // Number of IF statements
int noDOs = 0; // Number of DO statements
int noBEGINs = 0; // Number of BEGIN statements
int noWHILEs = 0; // Number of WHILE statements
int noCASEs = 0; // Number of CASE statements
int noOFs = 0; // Number of OF statements
// Define enumerator for the source atoms list
IEnumerator saEnum = SourceAtoms.GetEnumerator();
while (saEnum.MoveNext())
{
Atom = (ForthAtom)saEnum.Current;
// If the atom does not start with " or ." make the atom upper case
if (!Atom.Name.StartsWith(".\"") && !Atom.Name.StartsWith("\""))
{
Atom.Name = Atom.Name.ToUpper();
}
// Process atoms
switch (Atom.Name)
{
case "EXTERN": // Store information after EXTERN for calling methods at runtime
if (InWordDefinition)
{
RaiseException(SyntacticExceptionType._EDeclareOutsideWords, Atom);
}
saEnum.MoveNext(); // Advance to next atom
NextAtom = ((ForthAtom)saEnum.Current);
string ForthWord = NextAtom.Name; // Forth word name
if (IsReserved(ForthWord))
{
RaiseException(SyntacticExceptionType._EReservedWord, NextAtom);
}
if (!IsIdentifier(ForthWord))
{
RaiseException(SyntacticExceptionType._EInvalidIdentifier, NextAtom);
}
saEnum.MoveNext(); // Advance to next atom
NextAtom = ((ForthAtom)saEnum.Current);
string FileName = NextAtom.Name; // Library name
saEnum.MoveNext(); // Advance to next atom
NextAtom = ((ForthAtom)saEnum.Current);
string Callee = NextAtom.Name;
int DotPos = Callee.LastIndexOf('.');
string ClassName = Callee.Substring(0, DotPos);
string MethodName = Callee.Substring(DotPos + 1);
ExternalWords.Add(new ExternalWord {
Name = ForthWord, Library = FileName, Class = ClassName, Method = MethodName
});
break;
case "LIBRARY": // Store next atom as the name of the library
if (InWordDefinition)
{
RaiseException(SyntacticExceptionType._EDeclareOutsideWords, Atom);
}
saEnum.MoveNext(); // Advance to next atom
NextAtom = ((ForthAtom)saEnum.Current);
string libname = NextAtom.Name;
if (IsReserved(libname))
{
RaiseException(SyntacticExceptionType._EReservedWord, NextAtom);
}
if (!IsIdentifier(libname))
{
RaiseException(SyntacticExceptionType._EInvalidIdentifier, NextAtom);
}
LibraryName = libname;
break;
case "CONSTANT": // Associate the value on the global stack to the next atom
if (InWordDefinition)
{
RaiseException(SyntacticExceptionType._EDeclareOutsideWords, Atom);
}
saEnum.MoveNext(); // Advance to next atom
NextAtom = ((ForthAtom)saEnum.Current);
if (IsReserved(NextAtom.Name))
{
RaiseException(SyntacticExceptionType._EReservedWord, NextAtom);
}
if (!IsIdentifier(NextAtom.Name))
{
RaiseException(SyntacticExceptionType._EInvalidIdentifier, NextAtom);
}
if (IsConstOrVar(NextAtom.Name))
{
RaiseException(SyntacticExceptionType._EDuplicateConst, NextAtom);
}
if (SourceStack.Count == 0)
{
RaiseException(SyntacticExceptionType._EUnableToDefineConst, NextAtom);
}
GlobalConstants.Add(new ForthConstant {
Name = NextAtom.Name, Value = SourceStack.Pop()
}); // Add constant definiton to the list
break;
case "VARIABLE": // The next atom is the variable name with the initial size of 1
saEnum.MoveNext(); // Advance to next atom
NextAtom = ((ForthAtom)saEnum.Current);
if (IsReserved(NextAtom.Name))
{
RaiseException(SyntacticExceptionType._EReservedWord, NextAtom);
}
if (!IsIdentifier(NextAtom.Name))
{
RaiseException(SyntacticExceptionType._EInvalidIdentifier, NextAtom);
}
if (IsConstOrVar(NextAtom.Name))
{
RaiseException(SyntacticExceptionType._EDuplicateVar, NextAtom);
}
if (!InWordDefinition)
{
GlobalVariables.Add(new ForthVariable {
Name = NextAtom.Name, Size = 1
});
}
else
{
LocalVariables.Add(new ForthLocalVariable {
Name = NextAtom.Name, WordName = WordDef.Name
});
}
break;
case "ALLOT": // The last number on the stack is the additional size for the last defined variable
if (InWordDefinition)
{
RaiseException(SyntacticExceptionType._EDeclareOutsideWords, Atom);
}
if (SourceStack.Count == 0)
{
RaiseException(SyntacticExceptionType._EUnableToAllocVar, Atom);
}
if (SourceStack.Peek().GetType() != typeof(int))
{
RaiseException(SyntacticExceptionType._EWrongAllotConstType, Atom);
}
int AllotSize = (int)SourceStack.Pop(); // Get the ALLOT size
// Change the size of the last defined variable
int LastVarPos = GlobalVariables.Count - 1; // Get the position of the last variable we defined
ForthVariable fv = (ForthVariable)(GlobalVariables[LastVarPos]);
fv.Size += AllotSize;
GlobalVariables[LastVarPos] = fv; // Update changes in list
break;
case ":": // Begin word definition
if (InWordDefinition)
{
RaiseException(SyntacticExceptionType._ENestedWordsNotAllowed, Atom);
}
saEnum.MoveNext(); // Advance to next atom
NextAtom = ((ForthAtom)saEnum.Current);
NextAtom.Name = NextAtom.Name.ToUpper();
if (IsReserved(NextAtom.Name))
{
RaiseException(SyntacticExceptionType._EReservedWord, NextAtom);
}
if (!IsIdentifier(NextAtom.Name))
{
RaiseException(SyntacticExceptionType._EInvalidIdentifier, NextAtom);
}
InWordDefinition = true; // Signal beginning of word definition
WordDef = new ForthWord {
Name = NextAtom.Name
}; // Alloc here the structure, we fill it later
if (NextAtom.Name == "MAIN")
{
MainDefined = true;
}
break;
case ";": // End word definition
if (!InWordDefinition)
{
RaiseException(SyntacticExceptionType._EDeclareInsideWords, Atom);
}
// All control structures should be terminated by now
if ((noIFs > 0) || (noDOs > 0) || (noBEGINs > 0) || (noWHILEs > 0) || (noCASEs > 0))
{
RaiseException(SyntacticExceptionType._EUnfinishedControlStruct, Atom);
}
Words.Add(WordDef); // Add word to the list
InWordDefinition = false; // Signal end of word definition
break;
case "IF": // IF statement
if (!InWordDefinition)
{
RaiseException(SyntacticExceptionType._EDeclareInsideWords, Atom);
}
noIFs++;
goto default;
case "ELSE": // ELSE statement
if (!InWordDefinition)
{
RaiseException(SyntacticExceptionType._EDeclareInsideWords, Atom);
}
if (noIFs == 0)
{
RaiseException(SyntacticExceptionType._EMalformedIETStruct, Atom);
}
goto default;
case "THEN": // THEN statement
if (!InWordDefinition)
{
RaiseException(SyntacticExceptionType._EDeclareInsideWords, Atom);
}
if (noIFs == 0)
{
RaiseException(SyntacticExceptionType._EMalformedIETStruct, Atom);
}
noIFs--;
goto default;
case "DO": // DO statement
if (!InWordDefinition)
{
RaiseException(SyntacticExceptionType._EDeclareInsideWords, Atom);
}
noDOs++;
goto default;
case "LOOP": // LOOP statement
if (!InWordDefinition)
{
RaiseException(SyntacticExceptionType._EDeclareInsideWords, Atom);
}
if (noDOs == 0)
{
RaiseException(SyntacticExceptionType._EMalformedDLStruct, Atom);
}
noDOs--;
goto default;
case "+LOOP": // +LOOP statement
goto case "LOOP";
case "LEAVE": // LEAVE statement
if (!InWordDefinition)
{
RaiseException(SyntacticExceptionType._EDeclareInsideWords, Atom);
}
if (noDOs == 0)
{
RaiseException(SyntacticExceptionType._EMalformedDLStruct, Atom);
}
goto default;
case "BEGIN": // BEGIN statement
if (!InWordDefinition)
{
RaiseException(SyntacticExceptionType._EDeclareInsideWords, Atom);
}
noBEGINs++;
goto default;
case "WHILE": // WHILE statement
if (!InWordDefinition)
{
RaiseException(SyntacticExceptionType._EDeclareInsideWords, Atom);
}
if (noBEGINs == 0)
{
RaiseException(SyntacticExceptionType._EMalformedBWRStruct, Atom);
}
noWHILEs++;
goto default;
case "REPEAT": // REPEAT statement
if (!InWordDefinition)
{
RaiseException(SyntacticExceptionType._EDeclareInsideWords, Atom);
}
if ((noBEGINs == 0) || (noWHILEs == 0))
{
RaiseException(SyntacticExceptionType._EMalformedBWRStruct, Atom);
}
noBEGINs--;
noWHILEs--;
goto default;
case "AGAIN": // AGAIN statement
if (!InWordDefinition)
{
RaiseException(SyntacticExceptionType._EDeclareInsideWords, Atom);
}
if (noBEGINs == 0)
{
RaiseException(SyntacticExceptionType._EMalformedBAStruct, Atom);
}
noBEGINs--;
goto default;
case "UNTIL": // UNTIL statement
if (!InWordDefinition)
{
RaiseException(SyntacticExceptionType._EDeclareInsideWords, Atom);
}
if (noBEGINs == 0)
{
RaiseException(SyntacticExceptionType._EMalformedBUStruct, Atom);
}
noBEGINs--;
goto default;
case "CASE": // CASE statement
if (!InWordDefinition)
{
RaiseException(SyntacticExceptionType._EDeclareInsideWords, Atom);
}
noCASEs++;
goto default;
case "OF": // OF statement
if (!InWordDefinition)
{
RaiseException(SyntacticExceptionType._EDeclareInsideWords, Atom);
}
if (noCASEs == 0)
{
RaiseException(SyntacticExceptionType._EMalformedCOEStruct, Atom);
}
noOFs++;
goto default;
case "ENDOF": // ENDOF statement
if (!InWordDefinition)
{
RaiseException(SyntacticExceptionType._EDeclareInsideWords, Atom);
}
if (noOFs == 0)
{
RaiseException(SyntacticExceptionType._EMalformedCOEStruct, Atom);
}
noOFs--;
goto default;
case "ENDCASE": // ENDCASE statement
if (!InWordDefinition)
{
RaiseException(SyntacticExceptionType._EDeclareInsideWords, Atom);
}
if (noOFs > 0)
{
RaiseException(SyntacticExceptionType._EMalformedCOEStruct, Atom);
}
noCASEs--;
goto default;
default:
temp = Atom.Name; // Get the atom name
if (InWordDefinition)
{
WordDef.Definition.Add(temp); // Add atom to word definition
}
else
{
// The atom should now be a constant previously defined, a number or a string
int ConstValue; // Here we hold the value of the constant, in case we find it
if (GetConstIntValue(temp, out ConstValue))
{
SourceStack.Push(ConstValue);
}
else if (IsNumber(temp))
{
SourceStack.Push(Convert.ToInt32(temp));
}
else if (IsString(temp))
{
SourceStack.Push(temp.Trim(new char[] { '"' }));
}
else
{
RaiseException(SyntacticExceptionType._EInvalidIdentifier, Atom);
}
}
break;
}
}
// Check whether word MAIN is defined
if (MainDefined == false)
{
RaiseException(SyntacticExceptionType._EMainNotDefined);
}
}