protected static IMatched <Unit> getMatchFunction(ParseState state, string functionName, Parameters parameters, bool overriding,
string className)
{
var list = new List <If>();
if (state.Advance().ValueOrOriginal(out _, out var original))
{
state.CreateReturnType();
while (state.More)
{
var caseParser = new CaseParser(parameters[0].Name);
state.SkipEndOfLine();
if (caseParser.Scan(state).If(out _, out var anyException))
{
caseParser.If.AddReturnIf();
list.Add(caseParser.If);
}
else if (anyException.If(out var exception))
{
state.Regress();
return(failedMatch <Unit>(exception));
}
else
{
break;
}
}
if (list.Count == 0)
{
state.Regress();
state.RemoveReturnType();
return(notMatched <Unit>());
}
else
{
var stack = new Stack <If>();
foreach (var ifStatement in list)
{
stack.Push(ifStatement);
}
var previousIf = stack.Pop();
while (stack.Count > 0)
{
var current = stack.Pop();
current.ElseIf = previousIf.Some();
previousIf = current;
}
state.AddStatement(new MatchFunction(functionName, parameters, previousIf, overriding, className));
state.Regress();
state.RemoveReturnType();
return(Unit.Matched());
}
}
public override IMatched <Unit> ParseStatement(ParseState state, Token[] tokens)
{
var mutable = tokens[1].Text == "var";
var fieldName = tokens[3].Text;
var assignment = fieldName.IsNotEmpty();
state.Colorize(tokens, Color.Keyword, Color.Whitespace, Color.Identifier, Color.Whitespace, Color.Structure, Color.Whitespace,
Color.Keyword, Color.Whitespace);
if (getExpression(state, ExpressionFlags.Standard).ValueOrCast <Unit>(out var expression, out var asUnit))
{
var matchField = newLabel("match");
state.AddStatement(new AssignToNewField(false, matchField, expression));
state.Advance();
var caseParser = new CaseParser(fieldName, mutable, assignment, matchField, true, CaseType.Statement);
if (caseParser.Scan(state).ValueOrOriginal(out _, out asUnit))
{
var ifStatement = caseParser.If;
addMatchElse(ifStatement);
state.AddStatement(ifStatement);
state.Regress();
return(Unit.Matched());
}
else
{
state.Regress();
return(asUnit);
}
}
else
{
return(asUnit);
}
}