/// <summary>
/// Attempts to parse a string as a <see cref="PackageQualityFilter"/>.
/// Note that the parse is case insensitive, that white spaces are silently ignored and min/max can be reversed.
/// The <paramref name="head"/> is forwarded right after the match: the head may be on any kind of character.
/// <para>
/// Examples:
/// "Stable" (is the same as "Stable-Stable"): only <see cref="PackageQuality.Stable"/> is accepted
/// "CI-Stable" (is the same as "-Stable" or "CI-" or ""): everything is accepted.
/// "-ReleaseCandidate" (same as "CI-RC" or "CI-ReleaseCandidate"): everything except Stable.
/// "Exploratory-Preview": No CI, ReleaseCandidate, nor Stable.
/// </para>
/// </summary>
/// <param name="head">The string to parse (leading and internal white spaces between tokens are skipped).</param>
/// <param name="filter">The result.</param>
/// <returns>True on success, false on error.</returns>
public static bool TryParse(ref ReadOnlySpan <char> head, out PackageQualityFilter filter)
{
var start = head;
head = head.TrimStart();
bool hasMin = PackageQualityExtension.TryMatch(ref head, out var min);
bool hasMax = false;
PackageQuality max = PackageQuality.Stable;
var sHead = head;
if ((head = head.TrimStart()).Length > 0 && head[0] == '-')
{
if (!hasMin)
{
sHead = head;
}
head = head.Slice(1).TrimStart();
hasMax = PackageQualityExtension.TryMatch(ref head, out max);
if (!hasMax)
{
head = sHead;
}
}
else
{
head = sHead;
}
if (hasMin || hasMax)
{
if (max == PackageQuality.None)
{
max = PackageQuality.Stable;
}
if (min > max)
{
var t = max;
max = min;
min = t;
}
filter = new PackageQualityFilter(min, max == PackageQuality.None ? PackageQuality.Stable : max);
return(true);
}
filter = new PackageQualityFilter();
head = start;
return(false);
}
/// <summary>
/// Tries to parse "<see cref="SVersionLock"/>[,<see cref="PackageQuality"/>]" or "<see cref="PackageQuality"/>[,<see cref="SVersionLock"/>]".
/// Note that match is case insensitive, that white spaces are silently ignored, that all "Lock" wan be written as "Locked" and that "rc" is
/// a synonym of <see cref="PackageQuality.ReleaseCandidate"/>.
/// The <paramref name="head"/> is forwarded right after the match: the head may be on any kind of character.
/// </summary>
/// <param name="head">The string to parse (leading and internal white spaces are skipped).</param>
/// <param name="l">The read lock.</param>
/// <param name="q">The read quality.</param>
/// <returns>True on success, false otherwise.</returns>
public static bool TryParseLockAndMinQuality(ref ReadOnlySpan <char> head,
out SVersionLock l,
out PackageQuality q)
{
var sSaved = head;
l = SVersionLock.None;
q = PackageQuality.None;
if (head.Length == 0)
{
return(false);
}
if (SVersionLockExtension.TryMatch(ref Trim(ref head), out l))
{
if (TryMatch(ref Trim(ref head), ','))
{
// This handles None,None: if the first read is "None", then it could have been the "None" of the quality:
// if we don't match a Quality we give a second chance to the Lock.
if (!PackageQualityExtension.TryMatch(ref Trim(ref head), out q) && l == SVersionLock.None)
{
SVersionLockExtension.TryMatch(ref Trim(ref head), out l);
}
return(true);
}
return(true);
}
if (PackageQualityExtension.TryMatch(ref Trim(ref head), out q))
{
if (TryMatch(ref Trim(ref head), ','))
{
SVersionLockExtension.TryMatch(ref Trim(ref head), out l);
return(true);
}
return(true);
}
head = sSaved;
return(false);
}