/// <summary>
/// Attempts to parse a modification.
/// </summary>
static public bool TryParse(StringSlice inData, out VariantModification outModification)
{
inData = inData.Trim();
VariantModifyOperator op = default(VariantModifyOperator);
int operatorIdx = -1;
int operatorLength = 0;
VariantUtils.TryFindOperator(inData, '=', VariantModifyOperator.Set, ref operatorIdx, ref op, ref operatorLength);
VariantUtils.TryFindOperator(inData, '+', VariantModifyOperator.Add, ref operatorIdx, ref op, ref operatorLength);
VariantUtils.TryFindOperator(inData, '-', VariantModifyOperator.Subtract, ref operatorIdx, ref op, ref operatorLength);
VariantUtils.TryFindOperator(inData, '*', VariantModifyOperator.Multiply, ref operatorIdx, ref op, ref operatorLength);
VariantUtils.TryFindOperator(inData, '/', VariantModifyOperator.Divide, ref operatorIdx, ref op, ref operatorLength);
if (operatorIdx < 0)
{
outModification = default(VariantModification);
return(false);
}
outModification.Operator = op;
StringSlice key = inData.Substring(0, operatorIdx);
StringSlice operand = inData.Substring(operatorIdx + 1);
if (!TableKeyPair.TryParse(key, out outModification.VariableKey))
{
outModification = default(VariantModification);
return(false);
}
return(VariantOperand.TryParse(operand, out outModification.Operand));
}
/// <summary>
/// Attempts to parse a comparison.
/// </summary>
static public bool TryParse(StringSlice inData, out VariantComparison outComparison)
{
inData = inData.Trim();
VariantCompareOperator op = VariantCompareOperator.True;
int operatorIdx = -1;
int operatorLength = 0;
VariantUtils.TryFindOperator(inData, EqualsOperator, VariantCompareOperator.EqualTo, ref operatorIdx, ref op, ref operatorLength);
VariantUtils.TryFindOperator(inData, NotEqualOperator, VariantCompareOperator.NotEqualTo, ref operatorIdx, ref op, ref operatorLength);
VariantUtils.TryFindOperator(inData, GreaterThanOrEqualToOperator, VariantCompareOperator.GreaterThanOrEqualTo, ref operatorIdx, ref op, ref operatorLength);
VariantUtils.TryFindOperator(inData, LessThanOrEqualToOperator, VariantCompareOperator.LessThanOrEqualTo, ref operatorIdx, ref op, ref operatorLength);
VariantUtils.TryFindOperator(inData, GreaterThanOperator, VariantCompareOperator.GreaterThan, ref operatorIdx, ref op, ref operatorLength);
VariantUtils.TryFindOperator(inData, LessThanOperator, VariantCompareOperator.LessThan, ref operatorIdx, ref op, ref operatorLength);
VariantUtils.TryFindOperator(inData, NotOperator, VariantCompareOperator.False, ref operatorIdx, ref op, ref operatorLength);
VariantUtils.TryFindOperator(inData, ShortEqualsOperator, VariantCompareOperator.EqualTo, ref operatorIdx, ref op, ref operatorLength);
VariantUtils.TryFindOperator(inData, ExistsOperator, VariantCompareOperator.Exists, ref operatorIdx, ref op, ref operatorLength);
VariantUtils.TryFindOperator(inData, DoesNotExistOperator, VariantCompareOperator.DoesNotExist, ref operatorIdx, ref op, ref operatorLength);
if (operatorIdx < 0)
{
op = VariantCompareOperator.True;
}
outComparison.Operator = op;
StringSlice idSlice = StringSlice.Empty;
StringSlice operandSlice = StringSlice.Empty;
bool bRequiresOperand = true;
switch (op)
{
case VariantCompareOperator.False:
{
idSlice = inData.Substring(1).TrimStart();
bRequiresOperand = false;
break;
}
case VariantCompareOperator.True:
{
idSlice = inData;
bRequiresOperand = false;
break;
}
case VariantCompareOperator.Exists:
{
idSlice = inData.Substring(0, operatorIdx).TrimEnd();
bRequiresOperand = false;
break;
}
case VariantCompareOperator.DoesNotExist:
{
idSlice = inData.Substring(0, operatorIdx).TrimEnd();
bRequiresOperand = false;
break;
}
default:
{
idSlice = inData.Substring(0, operatorIdx).TrimEnd();
operandSlice = inData.Substring(operatorIdx + operatorLength).TrimStart();
break;
}
}
if (!VariantOperand.TryParse(idSlice, out outComparison.Left))
{
outComparison = default(VariantComparison);
return(false);
}
if (!bRequiresOperand)
{
outComparison.Right = default(VariantOperand);
return(true);
}
return(VariantOperand.TryParse(operandSlice, out outComparison.Right));
}