private FieldSetter([NotNull] IEnumerable <Assignment> assignments,
FindFieldCache findFieldCache = null)
{
_assignments = assignments.ToArray();
_values = new object[_assignments.Length];
_findFieldCache = findFieldCache ?? new FindFieldCache();
_stack = new Stack <object>();
_environment = new StandardEnvironment();
_text = null;
}
private ImplicitValue(
[NotNull] ExpressionEvaluator evaluator, bool isMissing,
string name = null, FindFieldCache findFieldCache = null)
{
Name = name;
IsMissing = isMissing;
FindFieldCache = findFieldCache;
_evaluator = evaluator;
_stack = new Stack <object>();
_environment = new StandardEnvironment();
}
/// <summary>
/// An implicit value for the given <paramref name="expression"/>.
/// If <paramref name="expression"/> is missing (<c>null</c> or empty),
/// the implicit value will always evaluate to <c>null</c>.
/// The <paramref name="name"/>, if present, serves as a prefix
/// in exception messages.
/// </summary>
public static ImplicitValue Create(
[CanBeNull] string expression, string name = null,
FindFieldCache findFieldCache = null)
{
expression = StringUtils.Trim(expression);
try
{
if (string.IsNullOrEmpty(expression))
{
var evaluator = ExpressionEvaluator.CreateConstant(null);
return(new ImplicitValue(evaluator, true, name, findFieldCache));
}
else
{
var evaluator = ExpressionEvaluator.Create(expression);
return(new ImplicitValue(evaluator, false, name, findFieldCache));
}
}
catch (Exception ex)
{
throw Error($"Invalid expression: {ex.Message}", name);
}
}
/// <summary>
/// Create a <see cref="FieldSetter"/> instance.
/// </summary>
/// <param name="text">The field assignments; syntax: name = expr { ; name = expr }</param>
/// <param name="findFieldCache">A cache for field index lookups (optional)</param>
/// <returns>A <see cref="FieldSetter"/> instance</returns>
public static FieldSetter Create([CanBeNull] string text,
FindFieldCache findFieldCache = null)
{
return(new FieldSetter(Parse(text ?? string.Empty), findFieldCache));
}
