protected void GetToken()
{
pToken = icode.Get();
token = pToken.Code;
pNode = icode.SymtabNode;
}
private void CondGetTokenAppend(TTokenCode tc, TErrorCode ec)
{
// -- Get another token only if the current one matches tc
if (tc == token) GetTokenAppend();
else OnError(ec);
}
private void ExecuteStatementList(TTokenCode terminator)
{
// -- Loop to execute statements and skip semicolons.
do
{
ExecuteStatement();
while (token == TTokenCode.Semicolon) GetToken();
} while (token != terminator);
}
private bool TokenIn(TTokenCode tc, TTokenCode[] pList)
{
if (pList == null || pList.Length == 0) return false; // empty list
return pList.Contains(tc);
}
protected void GetToken()
{
pToken = pScanner.Get();
token = pToken.Code;
}
private void Resync(TTokenCode[] pList1, TTokenCode[] pList2 = null, TTokenCode[] pList3 = null)
{
// -- Is the current otken in one of the lists?
bool errorFlag = (!TokenIn(token, pList1)) &&
(!TokenIn(token, pList2)) &&
(!TokenIn(token, pList3));
if (errorFlag)
{
// -- Nope. Flag it as an error.
TErrorCode errorCode = (token == TTokenCode.EndOfFile) ? TErrorCode.UnexpectedEndOfFile : TErrorCode.UnexpectedToken;
OnError(errorCode);
// -- Skip tokens
while ((!TokenIn(token, pList1)) &&
(!TokenIn(token, pList2)) &&
(!TokenIn(token, pList3)) &&
(token != TTokenCode.Period) &&
(token != TTokenCode.EndOfFile))
{
GetToken();
}
// -- Flag an unexpected end of file (if hanve't already)
if ((token == TTokenCode.EndOfFile) &&
(errorCode != TErrorCode.UnexpectedEndOfFile))
{
OnError(TErrorCode.UnexpectedEndOfFile);
}
}
}
/// <summary>
/// Parses the statement list until the terminator token
/// </summary>
/// <param name="terminator">The terminator.</param>
private void ParseStatementList(TTokenCode terminator)
{
// -- Loop to parse staements and to check for and skip semicolons.
do
{
ParseStatement();
if (TokenIn(token, tlStatementStart))
{
OnError(TErrorCode.MissingSemicolon);
}
else while (token == TTokenCode.Semicolon) GetTokenAppend();
} while ((token != terminator) && (token != TTokenCode.EndOfFile));
}
private void ParseIdentifierConstant(SymtabNode pId1, TTokenCode sign)
{
SymtabNode pId2 = Find(pToken.TokenString); // ptr to <id-2>
if (pId2.defn.how != TDefnCode.dcConstant)
{
OnError(TErrorCode.NotAConstantIdentifier);
TType.SetType(ref pId1.pType, TType.pDummyType);
GetToken();
return;
}
// -- Integer identifier
if (pId2.pType == TType.pIntegerType)
{
pId1.defn.constantValue.integerValue =
sign == TTokenCode.Minus ? -pId2.defn.constantValue.integerValue
: pId2.defn.constantValue.integerValue;
TType.SetType(ref pId1.pType, TType.pIntegerType);
}
// -- Real identifier
else if (pId2.pType == TType.pRealType)
{
pId1.defn.constantValue.realValue =
sign == TTokenCode.Minus ? -pId2.defn.constantValue.realValue
: pId2.defn.constantValue.realValue;
TType.SetType(ref pId1.pType, TType.pRealType);
}
// -- Character identifier: No unary sign allowed
else if (pId2.pType == TType.pCharType)
{
if (sign != TTokenCode.Dummy) OnError(TErrorCode.InvalidConstant);
pId1.defn.constantValue.characterValue =
pId2.defn.constantValue.characterValue;
TType.SetType(ref pId1.pType, TType.pCharType);
}
// -- Enumeration identifier: No unary sign allowed.
else if (pId2.pType.Form == TFormCode.fcEnum)
{
if (sign != TTokenCode.Dummy) OnError(TErrorCode.InvalidConstant);
pId1.defn.constantValue.integerValue =
pId2.defn.constantValue.integerValue;
TType.SetType(ref pId1.pType, pId2.pType);
}
// -- Array identifier: Must be character array, and
// no unary sign allowed.
else if (pId2.pType.Form == TFormCode.fcArray)
{
if ((sign != TTokenCode.Dummy) ||
(pId2.pType.array.pElmtType != TType.pCharType))
{
OnError(TErrorCode.InvalidConstant);
}
pId1.defn.constantValue.stringValue =
pId2.defn.constantValue.stringValue;
TType.SetType(ref pId1.pType, pId2.pType);
}
GetToken();
}
public void Put(TTokenCode tokenCode)
{
m_formatter.Write((int)tokenCode);
}
private void AddReservedWord(string tokenString, TTokenCode tokenCode)
{
ReservedWord rw = new ReservedWord() { Code = tokenCode, TokenString = tokenString };
reservedWords.Add(tokenString.ToLower(), rw);
}
