private void RaiseException(ExceptionType exc, ForthAtom atom)
{
switch (exc)
{
case ExceptionType._EDeclareOutsideWords:
throw new Exception(atom.Name + " should be declared outside words. (" + atom.FileName + ":" + atom.LineNumber + ")");
case ExceptionType._EDeclareInsideWords:
throw new Exception(atom.Name + " should be declared inside words. (" + atom.FileName + ":" + atom.LineNumber + ")");
case ExceptionType._EReservedWord:
throw new Exception(atom.Name + " is a reserved identifier. (" + atom.FileName + ":" + atom.LineNumber + ")");
case ExceptionType._EInvalidIdentifier:
throw new Exception(atom.Name + " is an invalid identifier. (" + atom.FileName + ":" + atom.LineNumber + ")");
case ExceptionType._EUnableToDefineConst:
throw new Exception("Unable to define constant " + atom.Name + ". Number or string required before CONSTANT. (" + atom.FileName + ":" + atom.LineNumber + ")");
case ExceptionType._EUnableToAllocVar:
throw new Exception("Unable to alloc variable space " + atom.Name + ". Number needed before ALLOT. (" + atom.FileName + ":" + atom.LineNumber + ")");
case ExceptionType._EUnexpectedEndOfFile:
throw new Exception("Unexpected end of file " + atom.FileName + ".");
case ExceptionType._EWrongAllotConstType:
throw new Exception("Wrong constant type specified for ALLOT. Use an integer. (" + atom.FileName + ":" + atom.LineNumber + ")");
case ExceptionType._ENestedWordsNotAllowed:
throw new Exception("Nested words are not allowed. (" + atom.FileName + ":" + atom.LineNumber + ")");
case ExceptionType._EMalformedBWRStruct:
throw new Exception("Malformed BEGIN-WHILE-REPEAT control structure. (" + atom.FileName + ":" + atom.LineNumber + ")");
case ExceptionType._EMalformedBAStruct:
throw new Exception("Malformed BEGIN-AGAIN control structure. (" + atom.FileName + ":" + atom.LineNumber + ")");
case ExceptionType._EMalformedBUStruct:
throw new Exception("Malformed BEGIN-UNTIL control structure. (" + atom.FileName + ":" + atom.LineNumber + ")");
case ExceptionType._EMalformedIETStruct:
throw new Exception("Malformed IF-ELSE-THEN control structure. (" + atom.FileName + ":" + atom.LineNumber + ")");
case ExceptionType._EMalformedCOEStruct:
throw new Exception("Malformed CASE-OF-ENDCASE control structure. (" + atom.FileName + ":" + atom.LineNumber + ")");
case ExceptionType._EUnfinishedControlStruct:
throw new Exception("Control structures must be terminated before ';'. (" + atom.FileName + ":" + atom.LineNumber + ")");
case ExceptionType._EMainNotDefined:
throw new Exception("Program starting point is missing. Please define the word MAIN.");
case ExceptionType._EDuplicateConst:
throw new Exception("Constant redefines an already defined constant or variable. (" + atom.FileName + ":" + atom.LineNumber + ")");
case ExceptionType._EDuplicateVar:
throw new Exception("Variable redefines an already defined constant or variable. (" + atom.FileName + ":" + atom.LineNumber + ")");
}
}
// ProcessLoadDirectives - Parses the atom list and recursively processes the LOAD directives
// Input: None
// Output: Modifies the 'SourceAtoms' global variable
private void ProcessLoadDirectives()
{
string IncludeFile; // Name of the file to parse
int LoadPosition; // Position of the "LOAD" directive in the array
while (true)
{
LoadPosition = -1; // Initially not found
// Get the position of the 'LOAD' directive in the atom list
for (int i = 0; i < SourceAtoms.Count; i++)
{
ForthAtom atom = (ForthAtom)SourceAtoms[i];
if (atom.Name.ToLower() == "load")
{
LoadPosition = i;
break;
}
}
if (LoadPosition == -1)
{
break; // No need to continue (not found)
}
try
{
IncludeFile = ((ForthAtom)SourceAtoms[LoadPosition + 1]).Name; // Get the name of the file to include
}
catch (Exception)
{
ForthAtom atom = (ForthAtom)SourceAtoms[LoadPosition];
throw new Exception("Missing name of the include file. (" + atom.FileName + "," + atom.LineNumber + ")"); // Signal error if no file name is supplied
}
// Merge the atoms for the two files
SourceAtoms.RemoveRange(LoadPosition, 2);
ArrayList NewAtoms = ProcessSourceFile(IncludeFile);
SourceAtoms.InsertRange(LoadPosition, NewAtoms);
}
}
// RaiseException - Throws a specified exception
// Input: ExceptionType - the code of the exception to be thrown
// ForthAtom - the atom (with file name and line number) that caused the error
// Output: None
// Overloads: 1
private void RaiseException(ExceptionType exc)
{
ForthAtom atom = new ForthAtom("", "", 0); // Create an "empty" atom
RaiseException(exc, atom);
}