| // Copyright (c) 2014, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| /** |
| * The interface used to access the result of constant evaluation. |
| * |
| * Because the analyzer does not have any of the code under analysis loaded, it |
| * does not do real evaluation. Instead it performs a symbolic computation and |
| * presents those results through this interface. |
| * |
| * Instances of these constant values are accessed through the |
| * [element model](../element/element.dart). |
| */ |
| import 'package:analyzer/dart/element/type.dart'; |
| |
| /** |
| * A representation of the value of a compile-time constant expression. |
| * |
| * Note that, unlike the mirrors system, the object being represented does *not* |
| * exist. This interface allows static analysis tools to determine something |
| * about the state of the object that would exist if the code that creates the |
| * object were executed, but none of the code being analyzed is actually |
| * executed. |
| * |
| * Clients may not extend, implement or mix-in this class. |
| */ |
| abstract class DartObject { |
| /** |
| * Return `true` if the value of the object being represented is known. |
| * |
| * This method will return `false` if |
| * * the value being represented is the value of a declared variable (a |
| * variable whose value is provided at run-time using a `-D` command-line |
| * option), or |
| * * the value is a function. |
| * |
| * The result of this method does not imply anything about the state of |
| * object representations returned by the method [getField], those that are |
| * elements of the list returned by [toListValue], or the keys or values in |
| * the map returned by [toMapValue]. For example, a representation of a list |
| * can return `true` even if one or more of the elements of that list would |
| * return `false`. |
| */ |
| bool get hasKnownValue; |
| |
| /** |
| * Return `true` if the object being represented represents the value 'null'. |
| */ |
| bool get isNull; |
| |
| /** |
| * Return a representation of the type of the object being represented. |
| * |
| * For values resulting from the invocation of a 'const' constructor, this |
| * will be a representation of the run-time type of the object. |
| * |
| * For values resulting from a literal expression, this will be a |
| * representation of the static type of the value -- `int` for integer |
| * literals, `List` for list literals, etc. -- even when the static type is an |
| * abstract type (such as `List`) and hence will never be the run-time type of |
| * the represented object. |
| * |
| * For values resulting from any other kind of expression, this will be a |
| * representation of the result of evaluating the expression. |
| * |
| * Return `null` if the expression cannot be evaluated, either because it is |
| * not a valid constant expression or because one or more of the values used |
| * in the expression does not have a known value. |
| * |
| * This method can return a representation of the type, even if this object |
| * would return `false` from [hasKnownValue]. |
| */ |
| ParameterizedType get type; |
| |
| /** |
| * Return a representation of the value of the field with the given [name]. |
| * |
| * Return `null` if either the object being represented does not have a field |
| * with the given name or if the implementation of the class of the object is |
| * invalid, making it impossible to determine that value of the field. |
| * |
| * Note that, unlike the mirrors API, this method does *not* invoke a getter; |
| * it simply returns a representation of the known state of a field. |
| */ |
| DartObject getField(String name); |
| |
| /** |
| * Return a boolean corresponding to the value of the object being |
| * represented, or `null` if |
| * * this object is not of type 'bool', |
| * * the value of the object being represented is not known, or |
| * * the value of the object being represented is `null`. |
| */ |
| bool toBoolValue(); |
| |
| /** |
| * Return a double corresponding to the value of the object being represented, |
| * or `null` |
| * if |
| * * this object is not of type 'double', |
| * * the value of the object being represented is not known, or |
| * * the value of the object being represented is `null`. |
| */ |
| double toDoubleValue(); |
| |
| /** |
| * Return an integer corresponding to the value of the object being |
| * represented, or `null` if |
| * * this object is not of type 'int', |
| * * the value of the object being represented is not known, or |
| * * the value of the object being represented is `null`. |
| */ |
| int toIntValue(); |
| |
| /** |
| * Return a list corresponding to the value of the object being represented, |
| * or `null` if |
| * * this object is not of type 'List', or |
| * * the value of the object being represented is `null`. |
| */ |
| List<DartObject> toListValue(); |
| |
| /** |
| * Return a map corresponding to the value of the object being represented, or |
| * `null` if |
| * * this object is not of type 'Map', or |
| * * the value of the object being represented is `null`. |
| */ |
| Map<DartObject, DartObject> toMapValue(); |
| |
| /** |
| * Return a set corresponding to the value of the object being represented, |
| * or `null` if |
| * * this object is not of type 'Set', or |
| * * the value of the object being represented is `null`. |
| */ |
| Set<DartObject> toSetValue(); |
| |
| /** |
| * Return a string corresponding to the value of the object being represented, |
| * or `null` if |
| * * this object is not of type 'String', |
| * * the value of the object being represented is not known, or |
| * * the value of the object being represented is `null`. |
| */ |
| String toStringValue(); |
| |
| /** |
| * Return a string corresponding to the value of the object being represented, |
| * or `null` if |
| * * this object is not of type 'Symbol', or |
| * * the value of the object being represented is `null`. |
| * (We return the string |
| */ |
| String toSymbolValue(); |
| |
| /** |
| * Return the representation of the type corresponding to the value of the |
| * object being represented, or `null` if |
| * * this object is not of type 'Type', or |
| * * the value of the object being represented is `null`. |
| */ |
| DartType toTypeValue(); |
| } |