1- // Patch flags are optimization hints generated by the compiler.
2- // when a block with dynamicChildren is encountered during diff, the algorithm
3- // enters "optimized mode". In this mode, we know that the vdom is produced by
4- // a render function generated by the compiler, so the algorithm only needs to
5- // handle updates explicitly marked by these patch flags.
6-
7- // Patch flags can be combined using the | bitwise operator and can be checked
8- // using the & operator, e.g.
9- //
10- // const flag = TEXT | CLASS
11- // if (flag & TEXT) { ... }
12- //
13- // Check the `patchElement` function in './renderer.ts' to see how the
14- // flags are handled during diff.
15-
1+ /**
2+ * Patch flags are optimization hints generated by the compiler.
3+ * when a block with dynamicChildren is encountered during diff, the algorithm
4+ * enters "optimized mode". In this mode, we know that the vdom is produced by
5+ * a render function generated by the compiler, so the algorithm only needs to
6+ * handle updates explicitly marked by these patch flags.
7+ *
8+ * Patch flags can be combined using the | bitwise operator and can be checked
9+ * using the & operator, e.g.
10+ *
11+ * ```js
12+ * const flag = TEXT | CLASS
13+ * if (flag & TEXT) { ... }
14+ * ```
15+ *
16+ * Check the `patchElement` function in './renderer.ts' to see how the
17+ * flags are handled during diff.
18+ */
1619export const enum PatchFlags {
17- // Indicates an element with dynamic textContent (children fast path)
20+ /**
21+ * Indicates an element with dynamic textContent (children fast path)
22+ */
1823 TEXT = 1 ,
1924
20- // Indicates an element with dynamic class binding.
25+ /**
26+ * Indicates an element with dynamic class binding.
27+ */
2128 CLASS = 1 << 1 ,
2229
23- // Indicates an element with dynamic style
24- // The compiler pre-compiles static string styles into static objects
25- // + detects and hoists inline static objects
26- // e.g. style="color: red" and :style="{ color: 'red' }" both get hoisted as
27- // const style = { color: 'red' }
28- // render() { return e('div', { style }) }
30+ /**
31+ * Indicates an element with dynamic style
32+ * The compiler pre-compiles static string styles into static objects
33+ * + detects and hoists inline static objects
34+ * e.g. style="color: red" and :style="{ color: 'red' }" both get hoisted as
35+ * const style = { color: 'red' }
36+ * render() { return e('div', { style }) }
37+ */
2938 STYLE = 1 << 2 ,
3039
31- // Indicates an element that has non-class/style dynamic props.
32- // Can also be on a component that has any dynamic props (includes
33- // class/style). when this flag is present, the vnode also has a dynamicProps
34- // array that contains the keys of the props that may change so the runtime
35- // can diff them faster (without having to worry about removed props)
40+ /**
41+ * Indicates an element that has non-class/style dynamic props.
42+ * Can also be on a component that has any dynamic props (includes
43+ * class/style). when this flag is present, the vnode also has a dynamicProps
44+ * array that contains the keys of the props that may change so the runtime
45+ * can diff them faster (without having to worry about removed props)
46+ */
3647 PROPS = 1 << 3 ,
3748
38- // Indicates an element with props with dynamic keys. When keys change, a full
39- // diff is always needed to remove the old key. This flag is mutually
40- // exclusive with CLASS, STYLE and PROPS.
49+ /**
50+ * Indicates an element with props with dynamic keys. When keys change, a full
51+ * diff is always needed to remove the old key. This flag is mutually
52+ * exclusive with CLASS, STYLE and PROPS.
53+ */
4154 FULL_PROPS = 1 << 4 ,
4255
43- // Indicates an element with event listeners (which need to be attached
44- // during hydration)
56+ /**
57+ * Indicates an element with event listeners (which need to be attached
58+ * during hydration)
59+ */
4560 HYDRATE_EVENTS = 1 << 5 ,
4661
47- // Indicates a fragment whose children order doesn't change.
62+ /**
63+ * Indicates a fragment whose children order doesn't change.
64+ */
4865 STABLE_FRAGMENT = 1 << 6 ,
4966
50- // Indicates a fragment with keyed or partially keyed children
67+ /**
68+ * Indicates a fragment with keyed or partially keyed children
69+ */
5170 KEYED_FRAGMENT = 1 << 7 ,
5271
53- // Indicates a fragment with unkeyed children.
72+ /**
73+ * Indicates a fragment with unkeyed children.
74+ */
5475 UNKEYED_FRAGMENT = 1 << 8 ,
5576
56- // Indicates an element that only needs non-props patching, e.g. ref or
57- // directives (onVnodeXXX hooks). since every patched vnode checks for refs
58- // and onVnodeXXX hooks, it simply marks the vnode so that a parent block
59- // will track it.
77+ /**
78+ * Indicates an element that only needs non-props patching, e.g. ref or
79+ * directives (onVnodeXXX hooks). since every patched vnode checks for refs
80+ * and onVnodeXXX hooks, it simply marks the vnode so that a parent block
81+ * will track it.
82+ */
6083 NEED_PATCH = 1 << 9 ,
6184
62- // Indicates a component with dynamic slots (e.g. slot that references a v-for
63- // iterated value, or dynamic slot names).
64- // Components with this flag are always force updated.
85+ /**
86+ * Indicates a component with dynamic slots (e.g. slot that references a v-for
87+ * iterated value, or dynamic slot names).
88+ * Components with this flag are always force updated.
89+ */
6590 DYNAMIC_SLOTS = 1 << 10 ,
6691
67- // SPECIAL FLAGS -------------------------------------------------------------
68-
69- // Special flags are negative integers. They are never matched against using
70- // bitwise operators (bitwise matching should only happen in branches where
71- // patchFlag > 0), and are mutually exclusive. When checking for a special
72- // flag, simply check patchFlag === FLAG.
73-
74- // Indicates a hoisted static vnode. This is a hint for hydration to skip
75- // the entire sub tree since static content never needs to be updated.
92+ /**
93+ * Indicates a fragment that was created only because the user has placed
94+ * comments at the root level of a template. This is a dev-only flag since
95+ * comments are stripped in production.
96+ */
97+ DEV_ROOT_FRAGMENT = 1 << 11 ,
98+
99+ /**
100+ * SPECIAL FLAGS -------------------------------------------------------------
101+ * Special flags are negative integers. They are never matched against using
102+ * bitwise operators (bitwise matching should only happen in branches where
103+ * patchFlag > 0), and are mutually exclusive. When checking for a special
104+ * flag, simply check patchFlag === FLAG.
105+ */
106+
107+ /**
108+ * Indicates a hoisted static vnode. This is a hint for hydration to skip
109+ * the entire sub tree since static content never needs to be updated.
110+ */
76111 HOISTED = - 1 ,
77-
78- // A special flag that indicates that the diffing algorithm should bail out
79- // of optimized mode. For example, on block fragments created by renderSlot()
80- // when encountering non-compiler generated slots (i.e. manually written
81- // render functions, which should always be fully diffed)
82- // OR manually cloneVNodes
112+ /**
113+ * A special flag that indicates that the diffing algorithm should bail out
114+ * of optimized mode. For example, on block fragments created by renderSlot()
115+ * when encountering non-compiler generated slots (i.e. manually written
116+ * render functions, which should always be fully diffed)
117+ * OR manually cloneVNodes
118+ */
83119 BAIL = - 2
84120}
85121
86- // dev only flag -> name mapping
122+ /**
123+ * dev only flag -> name mapping
124+ */
87125export const PatchFlagNames = {
88126 [ PatchFlags . TEXT ] : `TEXT` ,
89127 [ PatchFlags . CLASS ] : `CLASS` ,
@@ -94,8 +132,9 @@ export const PatchFlagNames = {
94132 [ PatchFlags . STABLE_FRAGMENT ] : `STABLE_FRAGMENT` ,
95133 [ PatchFlags . KEYED_FRAGMENT ] : `KEYED_FRAGMENT` ,
96134 [ PatchFlags . UNKEYED_FRAGMENT ] : `UNKEYED_FRAGMENT` ,
97- [ PatchFlags . DYNAMIC_SLOTS ] : `DYNAMIC_SLOTS` ,
98135 [ PatchFlags . NEED_PATCH ] : `NEED_PATCH` ,
136+ [ PatchFlags . DYNAMIC_SLOTS ] : `DYNAMIC_SLOTS` ,
137+ [ PatchFlags . DEV_ROOT_FRAGMENT ] : `DEV_ROOT_FRAGMENT` ,
99138 [ PatchFlags . HOISTED ] : `HOISTED` ,
100139 [ PatchFlags . BAIL ] : `BAIL`
101140}
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