private async Task <Expr> ParseExpr()
{
while (await mTokenizer.NextToken())
{
switch (mTokenizer.Token)
{
case ETokenType.Number:
return(Expr.MakeNumber(mTokenizer.Number));
default:
throw new STException(string.Format(Properties.Resources.NoExpectTokenException, mTokenizer.TokenStr), mTokenizer.Line, mTokenizer.Position);
}
}
return(null);
}
/// <summary>
/// Splitting (“3 - 2 * 6 - 1”) = [3, ‘-’], [2, ‘*’], [6, ‘-’], [1, ‘’]
/// </summary>
/// <returns></returns>
private async Task <LinkedList <Cell> > Split()
{
var pCells = new LinkedList <Cell>();
Cell pCell = null;
var pNegative = false;
Expr pExpr;
while (await mTokenizer.NextToken())
{
if (Symbols.DictOperators.TryGetValue(mTokenizer.Token, out ETypeExpr op))
{
if (op == ETypeExpr.Equal)
{
return(pCells);
}
if (pCell != null)
{
if (pNegative)
{
pCell.Expr = Expr.Negative(pCell.Expr);
pNegative = false;
}
pCell.TypeOp = op;
pCell = null;
}
else
{
if (!pNegative)
{
switch (op)
{
case ETypeExpr.Subtract:
pNegative = true;
continue;
case ETypeExpr.Add:
continue;
default:
throw new STException(string.Format(Properties.Resources.NoExpectTokenException, mTokenizer.TokenStr), mTokenizer.Line, mTokenizer.Position);
}
}
throw new STException(string.Format(Properties.Resources.NoExpectTokenException, mTokenizer.TokenStr), mTokenizer.Line, mTokenizer.Position);
}
}
else
{
if (Symbols.DictFuncs.TryGetValue(mTokenizer.Token, out ETypeExpr fn))
{
if (!await mTokenizer.NextToken())
{
throw new STException(string.Format(Properties.Resources.ExpectTokenException, Symbols.OpenParensChar), mTokenizer.Line, mTokenizer.Position);
}
mTokenizer.Back();
var pExprArg = await ParseExpr();
pExpr = Expr.Function(fn, pExprArg);
}
else
{
switch (mTokenizer.Token)
{
case ETokenType.CloseParens:
return(pCells);
case ETokenType.OpenParens:
pExpr = await ParseExpr();
if (mTokenizer.Token == ETokenType.Equal)
{
mTokenizer.Back();
}
break;
case ETokenType.Number:
pExpr = Expr.Number(mTokenizer.Number);
break;
case ETokenType.Identifier:
pExpr = Expr.Literal(mTokenizer.Identifier);
break;
default:
throw new STException(string.Format(Properties.Resources.NoExpectTokenException, mTokenizer.TokenStr), mTokenizer.Line, mTokenizer.Position);
}
}
if (pNegative)
{
pExpr = Expr.Negative(pExpr);
pNegative = false;
}
if (pCell != null)
{
pCell.TypeOp = ETypeExpr.Multiply;
}
pCell = new Cell(pExpr);
pCells.AddLast(pCell);
}
}
return(pCells);
}
//[Test]
static async Task TokernizerTest()
{
var pTexts = new[]
{
//"20$",
//"20",
//"20x",
//"(20)",
//"20x+30y+20x^2",
//"(sin (x))^2+(cos (x))^2=1"
//"x",
//"2x=3",
"20a+3b+c=1\nb=20",
};
foreach (var pText in pTexts)
{
try
{
using (var pReader = new StringReader(pText))
{
var pTokenizer = new ST.Tokenizer(pReader, CancellationToken.None, true);
Console.WriteLine($"{pText} :");
while (await pTokenizer.NextToken())
{
Console.Write($"Token : {pTokenizer.Token} ");
switch (pTokenizer.Token)
{
case ST.ETokenType.Number:
Console.WriteLine(pTokenizer.Number);
break;
case ST.ETokenType.Identifier:
Console.WriteLine(pTokenizer.Identifier);
break;
default:
Console.WriteLine();
break;
}
if (pTokenizer.EOF)
{
Console.WriteLine("EOF");
}
if (pTokenizer.EOL)
{
Console.WriteLine("EOL");
pTokenizer.ResetEOL = true;
}
}
}
}
catch (ST.STException ex)
{
var pLine = string.Empty;
using (var pReader = new StringReader(pText))
{
for (var i = ex.Line; i > 0; i--)
{
pLine = pReader.ReadLine();
}
}
PrintError(ex.Message);
PrintError(pLine);
PrintError($"{new string(' ', ex.Position - 1)}^");
}
catch (Exception ex)
{
PrintError(ex.Message);
}
}
}
