// TODO: Add tests
public static bool Skip(ref ReadOnlySpan <byte> remaining, out ReadOnlySpan <byte> skipped)
{
skipped = default;
var stack = new ResizableMemory <byte>(32);
var currentToken = JsonTokenType.None;
int i = 0;
bool success = false;
for (; i < remaining.Length || currentToken != JsonTokenType.None;)
{
// If we skipped an element and returned to the top-most level, stop skipping
if (success && currentToken == JsonTokenType.None)
{
break;
}
byte c = remaining[i];
switch (c)
{
case (byte)' ': // Whitespace
case (byte)'\n':
case (byte)'\r':
case (byte)'\t':
i++;
continue;
case (byte)'{':
i++;
stack.Push((byte)currentToken);
currentToken = JsonTokenType.StartObject;
break;
case (byte)'}':
if (currentToken != JsonTokenType.StartObject)
{
return(false);
}
i++;
currentToken = (JsonTokenType)stack.Pop();
success = true;
break;
case (byte)'[':
i++;
stack.Push((byte)currentToken);
currentToken = JsonTokenType.StartArray;
break;
case (byte)']':
if (currentToken != JsonTokenType.StartArray)
{
return(false);
}
i++;
currentToken = (JsonTokenType)stack.Pop();
success = true;
break;
case (byte)',':
if (currentToken != JsonTokenType.StartObject && currentToken != JsonTokenType.StartArray)
{
return(false);
}
i++;
break;
case (byte)':':
if (currentToken != JsonTokenType.StartObject)
{
return(false);
}
i++;
break;
case (byte)'n':
i += 4; // ull
success = true;
break;
case (byte)'t':
i += 4; // rue
success = true;
break;
case (byte)'f':
i += 5; // alse
success = true;
break;
case (byte)'"':
i++;
bool incomplete = true;
while (i < remaining.Length)
{
switch (remaining[i])
{
case (byte)'\\':
i += 2; // Skip next char
continue;
case (byte)'"':
i++;
incomplete = false;
break;
default:
i++;
continue;
}
break;
}
if (incomplete)
{
return(false);
}
success = true;
break;
case (byte)'-':
case (byte)'0':
case (byte)'1':
case (byte)'2':
case (byte)'3':
case (byte)'4':
case (byte)'5':
case (byte)'6':
case (byte)'7':
case (byte)'8':
case (byte)'9':
i++;
while (i < remaining.Length)
{
switch (remaining[i])
{
case (byte)'+':
case (byte)'-':
case (byte)'.':
case (byte)'0':
case (byte)'1':
case (byte)'2':
case (byte)'3':
case (byte)'4':
case (byte)'5':
case (byte)'6':
case (byte)'7':
case (byte)'8':
case (byte)'9':
case (byte)'e':
case (byte)'E':
i++;
continue;
default: // Crossed into next token
break;
}
break;
}
success = true;
break;
default:
return(false);
}
}
// Incomplete object/array
if (currentToken != JsonTokenType.None)
{
return(false);
}
skipped = remaining.Slice(0, i);
remaining = remaining.Slice(i);
return(true);
}