1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
/// A constant that is true if the application was compiled in release mode.
///
/// More specifically, this is a constant that is true if the application was
/// compiled in Dart with the '-Ddart.vm.product=true' flag.
///
/// Since this is a const value, it can be used to indicate to the compiler that
/// a particular block of code will not be executed in release mode, and hence
/// can be removed.
///
/// Generally it is better to use [kDebugMode] or `assert` to gate code, since
/// using [kReleaseMode] will introduce differences between release and profile
/// builds, which makes performance testing less representative.
///
/// See also:
///
/// * [kDebugMode], which is true in debug builds.
/// * [kProfileMode], which is true in profile builds.
const bool kReleaseMode = bool.fromEnvironment('dart.vm.product', defaultValue: false);
/// A constant that is true if the application was compiled in profile mode.
///
/// More specifically, this is a constant that is true if the application was
/// compiled in Dart with the '-Ddart.vm.profile=true' flag.
///
/// Since this is a const value, it can be used to indicate to the compiler that
/// a particular block of code will not be executed in profile mode, an hence
/// can be removed.
///
/// See also:
///
/// * [kDebugMode], which is true in debug builds.
/// * [kReleaseMode], which is true in release builds.
const bool kProfileMode = bool.fromEnvironment('dart.vm.profile', defaultValue: false);
/// A constant that is true if the application was compiled in debug mode.
///
/// More specifically, this is a constant that is true if the application was
/// not compiled with '-Ddart.vm.product=true' and '-Ddart.vm.profile=true'.
///
/// Since this is a const value, it can be used to indicate to the compiler that
/// a particular block of code will not be executed in debug mode, and hence
/// can be removed.
///
/// An alternative strategy is to use asserts, as in:
///
/// ```dart
/// assert(() {
/// // ...debug-only code here...
/// return true;
/// }());
/// ```
///
/// See also:
///
/// * [kReleaseMode], which is true in release builds.
/// * [kProfileMode], which is true in profile builds.
const bool kDebugMode = !kReleaseMode && !kProfileMode;
/// The epsilon of tolerable double precision error.
///
/// This is used in various places in the framework to allow for floating point
/// precision loss in calculations. Differences below this threshold are safe to
/// disregard.
const double precisionErrorTolerance = 1e-10;
/// A constant that is true if the application was compiled to run on the web.
///
/// This implementation takes advantage of the fact that JavaScript does not
/// support integers. In this environment, Dart's doubles and ints are
/// backed by the same kind of object. Thus a double `0.0` is identical
/// to an integer `0`. This is not true for Dart code running in AOT or on the
/// VM.
const bool kIsWeb = identical(0, 0.0);