public override IEnumerable <MatchResult> Match(Value v, MatchContext context)
{
if (!(v is ExpressionValue expr))
{
return(new MatchResult[0]);
}
return(_head.Match(expr.Head, context)
.SelectMany(res => PatternMatching.SequenceMatch(_parts, expr.Parts, res.Context)
.Select(partRes => partRes.Context.WithMatch(_engine.Expr(
_engine.PatternMatching.ToSingle(res.SequenceMatch),
partRes.SequenceMatch
)))));
}