public static ArgsToken ParseAndChooseArguments(Scope scope, OperatorToken openBracketToken, Definition[] sigDefs, out Definition selectedDef)
{
#if DEBUG
if (sigDefs == null)
{
throw new ArgumentNullException("sigDefs");
}
if (sigDefs.Length == 0)
{
throw new ArgumentException("sigDefs must contain at least one signature definition.");
}
#endif
if (sigDefs.Length == 1)
{
selectedDef = sigDefs[0];
return(Parse(scope, openBracketToken, sigDefs[0].ArgumentsSignature));
}
var code = scope.Code;
var ret = new ArgsToken(scope, openBracketToken);
scope = scope.Clone();
scope.Hint |= ScopeHint.SuppressStatementStarts;
var tokens = new List <Token>();
var dataTypes = new List <DataType>();
List <Token> bestTokens = null;
var bestConfidence = 0.0f;
Definition bestSigDef = null;
var codeResetPos = code.Position;
foreach (var sigDef in sigDefs)
{
var args = sigDef.Arguments.ToArray();
var argIndex = 0;
var expectingDataType = true;
tokens.Clear();
dataTypes.Clear();
code.Position = codeResetPos;
while (code.SkipWhiteSpace())
{
code.Peek();
if (code.Text == ")")
{
tokens.Add(new OperatorToken(scope, code.MovePeekedSpan(), ")"));
ret._terminated = true;
break;
}
else if (code.Text == ",")
{
tokens.Add(new OperatorToken(scope, code.MovePeekedSpan(), ","));
argIndex++;
expectingDataType = true;
continue;
}
var exp = ExpressionToken.TryParse(scope, _endTokens,
expectedDataType: argIndex < args.Length ? args[argIndex].DataType : null);
if (exp != null)
{
tokens.Add(exp);
if (expectingDataType)
{
dataTypes.Add(exp.ValueDataType);
}
expectingDataType = false;
}
else
{
break;
}
}
if (dataTypes.Count == args.Length)
{
var confidence = 1.0f;
for (int i = 0, ii = args.Length; i < ii; i++)
{
confidence *= DataType.CalcArgumentCompatibility(args[i].DataType, dataTypes[i]);
}
if (confidence > bestConfidence)
{
bestConfidence = confidence;
bestTokens = tokens;
bestSigDef = sigDef;
}
}
else if (bestTokens == null)
{
bestTokens = tokens;
bestConfidence = 0.0f;
bestSigDef = sigDef;
}
}
ret.AddTokens(bestTokens);
ret._sig = bestSigDef.ArgumentsSignature;
ret._sigAlternatives = (from s in sigDefs where s.ArgumentsSignature != ret._sig select s.ArgumentsSignature).ToArray();
selectedDef = bestSigDef;
return(ret);
}