/// <summary> /// Parses the version expression. /// </summary> public static bool TryParse(string value, out ComposerVersionExpression expression) => TryParse(value.AsSpan(), out expression);
/// <summary>
/// Parses the version expression.
/// </summary>
public static bool TryParse(ReadOnlySpan <char> value, out ComposerVersionExpression expression)
{
expression = default;
value = value.Trim();
// ranges
var range = value.IndexOf(Tokens.Range); // regexp
if (range > 0)
{
// A - B
if (ComposerVersion.TryParse(value.Slice(0, range), out var fromversion) &&
ComposerVersion.TryParse(value.Slice(range + Tokens.Range.Length), out var toversion))
{
expression = new RangeExpression {
From = fromversion, To = toversion,
};
return(true);
}
else
{
return(false);
}
}
else if (range == 0)
{
// - B
return(false);
}
// AND, highest precedence
var and = Tokens.AndRegex.Match(value.ToString());
if (and.Success)
{
var cap = and.Groups[1];
if (TryParse(value.Slice(0, cap.Index), out var leftexpr) &&
TryParse(value.Slice(cap.Index + cap.Length), out var rightexpr))
{
expression = new AndExpression {
Left = leftexpr, Right = rightexpr,
};
return(true);
}
}
// OR
var or = value.IndexOf(Tokens.Or);
if (or > 0)
{
// A || B
if (TryParse(value.Slice(0, or), out var left) &&
TryParse(value.Slice(or + Tokens.Or.Length), out var right))
{
expression = new OrExpression {
Left = left, Right = right,
};
return(true);
}
else
{
return(false);
}
}
else if (or == 0)
{
// invalid
return(false);
}
//
if (value.IsEmpty)
{
return(false);
}
// unary version ranges
Operation op;
if (value[0] == Tokens.CaretVersion)
{
op = Operation.CaretVersionRange;
value = value.Slice(1);
}
else if (value[0] == Tokens.TildeVersion)
{
op = Operation.TildeVersionRange;
value = value.Slice(1);
}
else if (value.StartsWith(Tokens.Lte))
{
op = Operation.LessThanOrEqual;
value = value.Slice(Tokens.Lte.Length);
}
else if (value.StartsWith(Tokens.Gte))
{
op = Operation.GreaterThanOrEqual;
value = value.Slice(Tokens.Gte.Length);
}
else if (value.StartsWith(Tokens.Ne))
{
op = Operation.NotEqual;
value = value.Slice(Tokens.Ne.Length);
}
else if (value[0] == Tokens.Lt)
{
op = Operation.LessThan;
value = value.Slice(1);
}
else if (value[0] == Tokens.Gt)
{
op = Operation.GreaterThan;
value = value.Slice(1);
}
else
{
op = Operation.Exact;
}
if (ComposerVersion.TryParse(value, out var version))
{
if (op == Operation.Exact)
{
expression = new ExactVersionExpression {
Version = version
};
}
else
{
expression = new UnaryExpression(op)
{
Version = version,
};
}
return(true);
}
//
return(false);
}
