private Statement statement()
{
if (TokenListItem < TokenList.Count())
{
lookahead = (int)TokenList[TokenListItem].tag;
switch (lookahead)
{
case (int)TokenTags.OPENBRACKET:
match((int)TokenTags.OPENBRACKET);
List <Statement> stateArr = new List <Statement>();
while (lookahead != (int)TokenTags.CLOSEBRACKET)
{
if ((TokenListItem) >= TokenList.Count())
{
break;
}
Statement foo = statement();
stateArr.Add(foo);
}
match((int)TokenTags.CLOSEBRACKET);
return(new CompoundStatement(stateArr.ToArray()));
case (int)TokenTags.FUNCTION:
match((int)TokenTags.FUNCTION);
int idindx2 = match((int)TokenTags.ID);
match((int)TokenTags.OPENCIRKBRACKET);
string funcname = ((Word)TokenList[idindx2]).lexeme;
List <Expression> func_parameters = new List <Expression>();
while (lookahead != (int)TokenTags.CLOSECIRKBRACKET)
{
int tokindx = match((int)TokenTags.ID);
string forfunctionID = ((Word)TokenList[tokindx]).lexeme;
if (IDs[forfunctionID] != null)
{
throw new Exception("Existed ID can`t be a parameter for your function");
}
//~~~
//~~~ я передаватиму у сворену юзером функію захардкодений параметр, значення якого при виклику заміниться
//~~~
IDExpr megacrutch = new IDExpr(forfunctionID, IDs);
megacrutch.SetValue(new NumbExpr(-666));
func_parameters.Add(megacrutch);
if (lookahead != (int)TokenTags.COMMA)
{
break;
}
else
{
match((int)TokenTags.COMMA);
}
}
match((int)TokenTags.CLOSECIRKBRACKET);
Statement body = statement();
UserFunctionStatement userFunctionStatement = new UserFunctionStatement(funcname, func_parameters.ToArray(), body, IDs, functions);
userFunctionStatement.SetTree(null);
return(userFunctionStatement);
case (int)TokenTags.IF:
match((int)TokenTags.IF);
match((int)TokenTags.OPENCIRKBRACKET);
Expression ifcondition = expression();
match((int)TokenTags.CLOSECIRKBRACKET);
Statement ifaction = statement();
IfStatement ifStatement = new IfStatement(ifcondition, ifaction);
ifStatement.SetTree(ifcondition);
return(ifStatement);
case (int)TokenTags.WHILE:
match((int)TokenTags.WHILE);
match((int)TokenTags.OPENCIRKBRACKET);
Expression condition = expression();
match((int)TokenTags.CLOSECIRKBRACKET);
Statement action = statement();
WhileStatement whileStatement = new WhileStatement(condition, action);
whileStatement.SetTree(condition);
return(whileStatement);
case (int)TokenTags.RETURN:
match((int)TokenTags.RETURN);
Expression retexpr = expression();
match((int)TokenTags.DOTCOMMA);
ReturnStatement RetState = new ReturnStatement(retexpr);
RetState.SetTree(retexpr);
return(RetState);
case (int)TokenTags.LET:
match((int)TokenTags.LET);
int idindx = match((int)TokenTags.ID);
match((int)TokenTags.ASSIGN);
Expression val = expression();
match((int)TokenTags.DOTCOMMA);
string id = Convert.ToString(((Word)TokenList[idindx]).lexeme);
LetStatement LetState = new LetStatement(id, val, IDs);
LetState.SetTree(val);
return(LetState);
case ((int)TokenTags.DOTCOMMA):
match((int)TokenTags.DOTCOMMA);
EmptyStatement emptyStatement = new EmptyStatement();
emptyStatement.SetTree(null);
return(emptyStatement);
case ((int)TokenTags.ID):
int idindxx = match((int)TokenTags.ID);
string idname = Convert.ToString(((Word)TokenList[idindxx]).lexeme);
match((int)TokenTags.ASSIGN);
Expression newval = expression();
match((int)TokenTags.DOTCOMMA);
AssignStatement assignStatement = new AssignStatement(idname, newval, IDs);
assignStatement.SetTree(newval);
return(assignStatement);
default:
Expression onlyexp = expression();
match((int)TokenTags.DOTCOMMA);
ExpressionStatement expressionStatement = new ExpressionStatement(onlyexp);
expressionStatement.SetTree(onlyexp);
return(expressionStatement);
}
}
string error = "Fatal error: don`t fitted statement";
throw new Exception(error);
}
private Expression expression()
{
Expression expr = null;
if (TokenListItem < TokenList.Count())
{
lookahead = (int)TokenList[TokenListItem].tag;
switch (lookahead)
{
case (int)TokenTags.BOPERATOR:
int operator_indx = match((int)TokenTags.BOPERATOR);
Expression eNumb = expression();
if (eNumb.Type != ExpressionTypes.Number)
{
throw new Exception("Must be a number");
}
switch (((Word)TokenList[operator_indx]).lexeme)
{
case "+":
return(new NumbExpr(Convert.ToDouble(eNumb.Value())));
case "-":
return(new NumbExpr((-1) * Convert.ToDouble(eNumb.Value())));
default: throw new Exception("Invalid expression term '" + ((Word)TokenList[operator_indx]).lexeme + "'");
}
case (int)TokenTags.NUMBER:
match((int)TokenTags.NUMBER);
Expression eNumb1 = new NumbExpr(((Numb)TokenList[TokenListItem - 1]).value);
if (lookahead == (int)TokenTags.STROPERATOR)
{
throw new Exception("Number operator expected;");
}
if (lookahead == (int)TokenTags.BOPERATOR)
{
return(matchBOPERATOR(eNumb1));
}
else
{
return(eNumb1);
}
case (int)TokenTags.LITERAL:
match((int)TokenTags.LITERAL);
Expression litr1 = new StrExpr(((Word)TokenList[TokenListItem - 1]).lexeme);
if (lookahead == (int)TokenTags.BOPERATOR)
{
throw new Exception("String operator expected;");
}
if (lookahead == (int)TokenTags.STROPERATOR)
{
return(matchSTROPERATOR(litr1));
}
else
{
return(litr1);
}
case (int)TokenTags.ID:
int IDindx = match((int)TokenTags.ID);
string str1 = ((Word)TokenList[IDindx]).lexeme;
IDExpr id1 = new IDExpr(str1, IDs);
if (lookahead == (int)TokenTags.BOPERATOR)
{
return(matchBOPERATOR(id1));
}
if (lookahead == (int)TokenTags.STROPERATOR)
{
return(matchSTROPERATOR(id1));
}
return(id1);
case (int)TokenTags.OPENCIRKBRACKET:
match((int)TokenTags.OPENCIRKBRACKET);
expr = expression();
match((int)TokenTags.CLOSECIRKBRACKET);
if (lookahead == (int)TokenTags.BOPERATOR)
{
return(matchBOPERATOR(expr));
}
if (lookahead == (int)TokenTags.STROPERATOR)
{
return(matchSTROPERATOR(expr));
}
return(expr);
case (int)TokenTags.CALL:
match((int)TokenTags.CALL);
int FunkNameTokeIndx = match((int)TokenTags.ID);
List <Expression> FunkParams = new List <Expression>();
match((int)TokenTags.OPENCIRKBRACKET);
while (lookahead != (int)TokenTags.CLOSECIRKBRACKET)
{
Expression param1 = expression();
FunkParams.Add(param1);
if (lookahead != (int)TokenTags.CLOSECIRKBRACKET)
{
match((int)TokenTags.COMMA);
}
else
{
break;
}
}
match((int)TokenTags.CLOSECIRKBRACKET);
string FunkName = ((Word)TokenList[FunkNameTokeIndx]).lexeme + "#" + Convert.ToString(FunkParams.Count());
Expression func = (matchFunk(FunkName)).Copy();
((Function)func).SetParameters(FunkParams.ToArray());
return(func);
default:
string err = "Syntax Error: not fited expression";
//MessageBox.Show(err);
throw new Exception(err);
}
}
else
{
string err = "Out of range";
//MessageBox.Show(err);
throw new Exception(err);
}
}