public static bool ParseWhen(this IParsingContextStream source, Func <char, bool> predicate, bool accept = false)
{
if (source.HasNext && predicate.Invoke(source.Next))
{
source.MoveNext();
if (accept)
{
source.Accept();
}
return(true);
}
return(false);
}
public static bool ParseChar(this IParsingContextStream source, char ch1, char ch2, bool accept = false)
{
if (source.HasNext && source.Next == ch1 || source.Next == ch2)
{
source.MoveNext();
if (accept)
{
source.Accept();
}
return(true);
}
return(false);
}
public static bool ParseOneOf(this IParsingContextStream source, ISet <char> charSet, bool accept = false, IEqualityComparer <char> charComparer = null)
{
if (source.HasNext && source.Next.IsContainedBy(charSet, charComparer))
{
source.MoveNext();
if (accept)
{
source.Accept();
}
return(true);
}
return(false);
}
public static int ParseDigits(this IParsingContextStream source, bool accept = false)
{
var count = 0;
while (source.HasNext && char.IsDigit(source.Next))
{
count++;
source.MoveNext();
}
if (accept && count > 0)
{
source.Accept();
}
return(count);
}
public static int ParseWhileOneOf(this IParsingContextStream source, ISet <char> charSet, bool accept = false, IEqualityComparer <char> charComparer = null)
{
var count = 0;
while (source.HasNext && source.Next.IsContainedBy(charSet, charComparer))
{
count++;
source.MoveNext();
}
if (accept && count > 0)
{
source.Accept();
}
return(count);
}
public static int ParseWhile(this IParsingContextStream source, Func <char, bool> predicate, bool accept = false)
{
var count = 0;
while (source.HasNext && predicate.Invoke(source.Next))
{
count++;
source.MoveNext();
}
if (accept && count > 0)
{
source.Accept();
}
return(count);
}
public static bool ParseChar(
this IParsingContextStream source,
char ch,
bool accept = false,
IEqualityComparer <char> charComparer = null)
{
if (source.HasNext && Equals(source.Next, ch, charComparer))
{
source.MoveNext();
if (accept)
{
source.Accept();
}
return(true);
}
return(false);
}
public static bool ParseText(this IParsingContextStream source, IEnumerable <char> text, IEqualityComparer <char> charComparer = null, bool accept = false)
{
foreach (var ch in text)
{
if (!source.MoveNext())
{
return(false);
}
var cur = source.Current;
if (!(charComparer?.Equals(ch, cur) ?? ch == cur))
{
return(false);
}
}
if (accept)
{
source.Accept();
}
return(true);
}
/// <inheritdoc />
protected override IParsingProduct TryParseInternal(IParsingContextStream ctx, ParsingOptions options)
{
return(ctx.MoveNext() && ctx.Current.IsAny(_range)
? ctx.Accept().CreateTermForAcceptedFragment(FXB.ExpressionTypes.CharTerm)
: null);
}
