/// <inheritdoc/>
public bool TryCompile(IReadOnlyList <MathExpression> arguments, ICompilationContext <object?> ctx, ITypeHintHandler hintHandler, [MaybeNullWhen(false)] out Expression expr)
{
if (arguments.Count != 3)
{
expr = null;
return(false);
}
var condition = hintHandler.TransformWithHint(arguments.First(), typeof(bool), ctx);
var hint = hintHandler.CurrentHint(ctx);
Expression?thenExpr = null, elseExpr = null;
Type? convertAllTo, lastThen, lastElse;
do
{
lastThen = thenExpr?.Type;
lastElse = elseExpr?.Type;
thenExpr = hintHandler.TransformWithHint(arguments[1], hint, ctx);
elseExpr = hintHandler.TransformWithHint(arguments[2], hint, ctx);
var allTypes = new[] { thenExpr.Type, elseExpr.Type };
convertAllTo = allTypes
.OrderByDescending(CompilerHelpers.EstimateTypeSize)
.Where(ty => allTypes.All(t => CompilerHelpers.HasConversionPathTo(t, ty)))
.FirstOrDefault(); // biggest one
}while (thenExpr.Type != elseExpr.Type && thenExpr.Type != convertAllTo &&
lastThen != thenExpr.Type && lastElse != elseExpr.Type);
if (convertAllTo == null)
{
throw new ArgumentException("True and False branches of condition do not have a common type to be converted to");
}
expr = Expression.Condition(CompilerHelpers.AsBoolean(condition),
CompilerHelpers.ConvertToType(thenExpr, convertAllTo),
CompilerHelpers.ConvertToType(elseExpr, convertAllTo));
return(true);
}
