public SyntaxParseResult <IN> ParseNonTerminal(IList <Token <IN> > tokens, NonTerminalClause <IN> nonTermClause,
int currentPosition)
{
var startPosition = currentPosition;
var endingPosition = 0;
var nt = Configuration.NonTerminals[nonTermClause.NonTerminalName];
var errors = new List <UnexpectedTokenSyntaxError <IN> >();
var i = 0;
var allAcceptableTokens = new List <IN>();
nt.Rules.ForEach(r =>
{
if (r != null && r.PossibleLeadingTokens != null)
{
allAcceptableTokens.AddRange(r.PossibleLeadingTokens);
}
});
allAcceptableTokens = allAcceptableTokens.Distinct().ToList();
var rules = nt.Rules
.Where(r => startPosition < tokens.Count && r.PossibleLeadingTokens.Contains(tokens[startPosition].TokenID) || r.MayBeEmpty)
.ToList();
if (rules.Count == 0)
{
return(NoMatchingRuleError(tokens, currentPosition, allAcceptableTokens));
}
var innerRuleErrors = new List <UnexpectedTokenSyntaxError <IN> >();
var greaterIndex = 0;
var rulesResults = new List <SyntaxParseResult <IN> >();
while (i < rules.Count)
{
var innerrule = rules[i];
var innerRuleRes = Parse(tokens, innerrule, startPosition, nonTermClause.NonTerminalName);
rulesResults.Add(innerRuleRes);
var other = greaterIndex == 0 && innerRuleRes.EndingPosition == 0;
if (innerRuleRes.EndingPosition > greaterIndex && innerRuleRes.Errors != null &&
!innerRuleRes.Errors.Any() || other)
{
greaterIndex = innerRuleRes.EndingPosition;
//innerRuleErrors.Clear();
innerRuleErrors.AddRange(innerRuleRes.Errors);
}
innerRuleErrors.AddRange(innerRuleRes.Errors);
i++;
}
errors.AddRange(innerRuleErrors);
SyntaxParseResult <IN> max = null;
if (rulesResults.Any())
{
if (rulesResults.Any(x => x.IsOk))
{
max = rulesResults.Where(x => x.IsOk).OrderBy(x => x.EndingPosition).Last();
}
else
{
max = rulesResults.Where(x => !x.IsOk).OrderBy(x => x.EndingPosition).Last();
}
}
else
{
max = new SyntaxParseResult <IN>();
max.IsError = true;
max.Root = null;
max.IsEnded = false;
max.EndingPosition = currentPosition;
}
var result = new SyntaxParseResult <IN>();
result.Errors = errors;
result.Root = max.Root;
result.EndingPosition = max.EndingPosition;
result.IsError = max.IsError;
result.IsEnded = max.IsEnded;
if (rulesResults.Any())
{
var terr = rulesResults.SelectMany(x => x.Errors).ToList();
var unexpected = terr.Cast <UnexpectedTokenSyntaxError <IN> >().ToList();
var expecting = unexpected.SelectMany(x => x.ExpectedTokens).ToList();
result.AddExpectings(expecting);
}
return(result);
}
public SyntaxParseResult <IN> ParseNonTerminal(IList <Token <IN> > tokens, NonTerminalClause <IN> nonTermClause,
int currentPosition)
{
var startPosition = currentPosition;
var endingPosition = 0;
var nt = Configuration.NonTerminals[nonTermClause.NonTerminalName];
var errors = new List <UnexpectedTokenSyntaxError <IN> >();
var i = 0;
var allAcceptableTokens = new List <IN>();
nt.Rules.ForEach(r =>
{
if (r != null && r.PossibleLeadingTokens != null)
{
allAcceptableTokens.AddRange(r.PossibleLeadingTokens);
}
});
allAcceptableTokens = allAcceptableTokens.Distinct().ToList();
var rules = nt.Rules
.Where(r => r.PossibleLeadingTokens.Contains(tokens[startPosition].TokenID) || r.MayBeEmpty)
.ToList();
if (rules.Count == 0)
{
errors.Add(new UnexpectedTokenSyntaxError <IN>(tokens[startPosition],
allAcceptableTokens.ToArray <IN>()));
}
var innerRuleErrors = new List <UnexpectedTokenSyntaxError <IN> >();
SyntaxParseResult <IN> okResult = null;
var greaterIndex = 0;
var allRulesInError = true;
var test = new List <SyntaxParseResult <IN> >();
while (i < rules.Count)
{
var innerrule = rules[i];
var innerRuleRes = Parse(tokens, innerrule, startPosition, nonTermClause.NonTerminalName);
if (!innerRuleRes.IsError && okResult == null ||
okResult != null && innerRuleRes.EndingPosition > okResult.EndingPosition)
{
okResult = innerRuleRes;
okResult.Errors = innerRuleRes.Errors;
endingPosition = innerRuleRes.EndingPosition;
}
else
{
test.Add(innerRuleRes);
}
var other = greaterIndex == 0 && innerRuleRes.EndingPosition == 0;
if (innerRuleRes.EndingPosition > greaterIndex && innerRuleRes.Errors != null &&
!innerRuleRes.Errors.Any() || other)
{
greaterIndex = innerRuleRes.EndingPosition;
innerRuleErrors.Clear();
innerRuleErrors.AddRange(innerRuleRes.Errors);
}
innerRuleErrors.AddRange(innerRuleRes.Errors);
allRulesInError = allRulesInError && innerRuleRes.IsError;
i++;
}
errors.AddRange(innerRuleErrors);
var result = new SyntaxParseResult <IN>();
result.Errors = errors;
if (okResult != null)
{
result.Root = okResult.Root;
result.IsError = false;
result.EndingPosition = okResult.EndingPosition;
result.IsEnded = okResult.IsEnded;
result.Errors = errors;
}
else
{
result.IsError = true;
result.Errors = errors;
greaterIndex = errors.Count > 0 ? errors.Select(e => e.UnexpectedToken.PositionInTokenFlow).Max() : 0;
result.EndingPosition = greaterIndex;
result.AddExpectings(errors.SelectMany(e => e.ExpectedTokens));
}
if (test.Any())
{
var terr = test.SelectMany(x => x.Errors).ToList();
var unexpected = terr.OfType <UnexpectedTokenSyntaxError <IN> >().ToList();
var expecting = unexpected.SelectMany(x => x.ExpectedTokens).ToList();
result.AddExpectings(expecting);
;
}
return(result);
}
