private static SubpatternSyntax?TrySimplify(SubpatternSyntax currentSubpattern)
{
if (!SimplifyPropertyPatternHelpers.IsSimplifiable(currentSubpattern, out var innerSubpattern, out var outerExpressionColon))
{
return(null);
}
// attempt to simplify the inner pattern we're pointing at as well (that way if the user
// invokes the fix on a top level property, we collapse as far inwards as possible).
innerSubpattern = TrySimplify(innerSubpattern) ?? innerSubpattern;
var innerExpressionColon = innerSubpattern.ExpressionColon;
if (!SimplifyPropertyPatternHelpers.IsMergable(outerExpressionColon.Expression) ||
!SimplifyPropertyPatternHelpers.IsMergable(innerExpressionColon?.Expression))
{
return(null);
}
var merged = Merge(outerExpressionColon, innerExpressionColon);
if (merged == null)
{
return(null);
}
return(currentSubpattern.WithExpressionColon(merged)
.WithPattern(innerSubpattern.Pattern)
.WithAdditionalAnnotations(Formatter.Annotation));
}
public static bool IsSimplifiable(
SubpatternSyntax subpattern,
[NotNullWhen(true)] out SubpatternSyntax?innerSubpattern,
[NotNullWhen(true)] out BaseExpressionColonSyntax?outerExpressionColon)
{
// can't simplify if we have anything inside other than a property pattern clause. i.e.
// `a: { b: ... } x` is not simplifiable as we'll lose the `x` binding for the `a` property.
//
// can't simplify `a: { }` or `a: { b: ..., c: ... }`
if (subpattern is
{
ExpressionColon : { } outer,
Pattern : RecursivePatternSyntax
{
Type : null,
PositionalPatternClause : null,
Designation : null,
PropertyPatternClause : { Subpatterns : { Count : 1 } subpatterns }
}
} &&
public override void VisitSubpattern(SubpatternSyntax node)
{
Log(node, "Unsupported Syntax !");
}
