private bool Equals(RankedType other)
{
return(Type == other.Type && Rank == other.Rank);
}
/// <summary> Extract the reflection rules from type <paramref name="t"/>. </summary>
public RuleSet(Type t, Type token, Type result, int end, IReadOnlyDictionary <int, IReadOnlyList <int> > publicChildren)
{
PublicChildren = publicChildren;
// Extract token names
TokenNames = token.GetEnumNames();
TokenType = token;
EndOfStream = end;
var maxRank = new Dictionary <Type, int>();
var rankedTypeId = new Dictionary <RankedType, int>();
var rankedTypes = new List <RankedType>();
var ruleId = new List <List <int> >();
var uncompiledRules = new List <UncompiledRule>();
// Explore methods to find those to be compiled
foreach (var m in t.GetMethods())
{
var ruleAttribute = m.GetCustomAttribute <RuleAttribute>();
if (ruleAttribute == null)
{
continue;
}
// Update the max-rank for this type
if (!maxRank.TryGetValue(m.ReturnType, out var tMaxRank) || tMaxRank < ruleAttribute.Rank)
{
maxRank[m.ReturnType] = ruleAttribute.Rank;
}
// Get or create the RankedType and its identifier
var rt = new RankedType(m.ReturnType, ruleAttribute.Rank);
if (!rankedTypeId.TryGetValue(rt, out var rtid))
{
rankedTypes.Add(rt);
ruleId.Add(new List <int>());
rankedTypeId.Add(rt, rtid = rankedTypeId.Count);
}
// Determine the number of optional parameters, to generate one
// rule for each parameter combination. This includes both optional
// terminals AND lists which allow zero elements.
var options = m.GetParameters()
.Count(p =>
(p.GetCustomAttribute <TerminalAttribute>()?.Optional ?? false) ||
(p.GetCustomAttribute <NonTerminalAttribute>()?.Optional ?? false) ||
(p.GetCustomAttribute <ListAttribute>()?.Min ?? 1) == 0);
var combinations = 1 << options;
var context = m.GetCustomAttribute <ContextAttribute>();
// Allocate news rule (not compiled yet) and bind to RankedType
for (var i = 0; i < combinations; ++i)
{
var rid = uncompiledRules.Count + TokenNames.Count;
uncompiledRules.Add(new UncompiledRule(m, i, context?.GetTag(m.ReturnType)));
ruleId[rtid].Add(rid);
}
}
MaxRank = maxRank;
RankedTypeId = rankedTypeId;
RankedTypes = rankedTypes;
RuleId = ruleId;
// All RankedTypes have been identified. Now explore method parameters
// to deduce actual rules, and generate any 'list' (star, actually) rules
// on-the-fly.
var listRules = new List <Rule>();
var nextListRule = uncompiledRules.Count + TokenNames.Count;
var rules = uncompiledRules.Select(r => Compile(r, ref nextListRule, listRules)).ToArray();
Rules = rules.Concat(listRules).ToArray();
// The starting tokens for each rule
var isStartOf = Enumerable.Range(TokenNames.Count, Rules.Count).Select(i =>
Rules.Select((r, j) => r.StartsWithRule(i) ? j : -1)
.Where(j => j >= 0).ToArray()).ToArray();
void PropagateStart(int stok, int rul)
{
foreach (var rul2 in isStartOf[rul])
{
if (!Rules[rul2].StartingTokens.Contains(stok))
{
Rules[rul2].StartingTokens.Add(stok);
PropagateStart(stok, rul2);
}
}
}
for (var r = 0; r < Rules.Count; ++r)
{
foreach (var tok in Rules[r].StartingTokens)
{
PropagateStart(tok, r);
}
}
// The reducing tokens for each rule
foreach (var r in Rules)
{
r.AddReducingToken(this, EndOfStream);
r.ExtractEndingTokens(this);
}
// Initial rules
if (!MaxRank.TryGetValue(result, out var resultMaxRank))
{
throw new Exception($"Unknown result type {result}.");
}
InitialRules = Enumerable.Range(0, resultMaxRank + 1)
.SelectMany(i => RankedTypeId.TryGetValue(new RankedType(result, i), out var id) ? RuleId[id] : new int[0])
.ToArray();
}