/// <summary>
/// Parses terminal symbols - like string constants
/// </summary>
static void ParseTerminals(ParseContext context)
{
for (var i = context.NonterminalStartPos; i <= context.Pos; i++)
{
var scanChar = context.Input[i];
var lastTerm = context.PreviousTag?.Value as TerminalTag;
if (lastTerm == null || lastTerm.AcceptsLetter(context, scanChar) == false)
{
foreach (var tt in terminalTags)
{
if (tt.AcceptsLetter(context, scanChar) != false)
{
context.AddTag(((TerminalTag)tt.Create()).AppendChar(scanChar));
break;
}
}
}
else
{
lastTerm.AppendChar(scanChar);
}
}
}
/// <summary>
/// Parses terminal symbols - like string constants
/// </summary>
static void ParseTerminals(ParseContext context) {
for (var i = context.NonterminalStartPos; i <= context.Pos; i++)
{
var scanChar = context.Input[i];
var lastTerm = context.PreviousTag?.Value as TerminalTag;
if (lastTerm == null || lastTerm.AcceptsLetter(context, scanChar) == false)
{
foreach (var tt in terminalTags)
{
if (tt.AcceptsLetter(context, scanChar) != false)
{
context.AddTag(((TerminalTag)tt.Create()).AppendChar(scanChar));
break;
}
}
} else lastTerm.AppendChar(scanChar);
}
}
LinkedList <Tag> SplitIntoTags(string input)
{
var candidates = new List <Tag>();
if (string.IsNullOrEmpty(input))
{
return(new LinkedList <Tag>());
}
context.Setup(input);
while (context.Pos < input.Length)
{
var letter = context.CurrentChar;
var mc = 0;
if (candidates.Count > 0)
{
for (var ci = candidates.Count - 1; ci >= 0; ci--)
{
var c = candidates[ci];
var ret = c.AcceptsLetter(context, letter);
if (ret == true)
{
context.AddTag(c.Create().Init(context.MatchedString));
candidates.Clear();
context.ResetNonterminalPos();
mc = 1;
break;
}
if (ret == null)
{
mc++;
}
else
{
candidates.RemoveAt(ci);
}
}
}
else
{
for (var ci = nonterminalTags.Count - 1; ci >= 0; ci--)
{
var c = nonterminalTags[ci];
var ret = c.AcceptsLetter(context, letter);
if (ret == true)
{
context.AddTag(c.Create().Init(context.MatchedString));
context.ResetNonterminalPos();
mc = 1;
break;
}
if (ret == null)
{
mc++;
candidates.Add(c);
}
}
}
if (mc == 0 || context.Pos == input.Length - 1) // we are not matching any nonterminal tags
{
ParseTerminals(context);
context.ResetNonterminalPos();
}
context.AdvancePos();
}
return(context.Tags);
}