private ExpressionValue EvaluateLeaf(ExpressionNode node)
{
Token token = node.Token;
if (token.IsNumber)
{
Number value;
if (!TokenHelper.TryConvertToNumber(node.Token, out value))
{
throw new Exception($"Can't convert token to number {node.Token}");
}
return(ExpressionValue.Create(value));
}
else if (token.TokenType == TokenType.TrueKeyword)
{
return(ExpressionValue.Create(true));
}
else if (token.TokenType == TokenType.FalseKeyword)
{
return(ExpressionValue.Create(false));
}
else if (token.TokenType == TokenType.Word)
{
return(EvaluateMacro(node));
}
else if (token.IsCharacter)
{
char cValue = '0';
if (!TokenHelper.TryConvertToChar(node.Token, out cValue))
{
throw new Exception($"Can't convert token to char {node.Token}");
}
return(ExpressionValue.Create(cValue));
}
else if (token.IsQuotedString)
{
string sValue = null;
if (!TokenHelper.TryConvertToString(token, out sValue))
{
throw new Exception($"Can't convert token to string {node.Token}");
}
return(ExpressionValue.Create(sValue));
}
else if (TokenHelper.IsKeyword(node.Token.TokenType))
{
return(ExpressionValue.Create(1));
}
else
{
throw new Exception($"Unexpected leaf token {node.Token}");
}
}
public void VerifyChar(char c)
{
Token token = new Token(TokenType.CharacterAnsi, "'" + c + "'");
char converted = '0';
Assert.True(Helper.TryConvertToChar(token, out converted));
Assert.Equal(c, converted);
token = new Token(TokenType.CharacterUnicode, "L'" + c + "'");
Assert.True(Helper.TryConvertToChar(token, out converted));
Assert.Equal(c, converted);
}