-
Notifications
You must be signed in to change notification settings - Fork 131
/
walk.go
63 lines (55 loc) · 1.74 KB
/
walk.go
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
/*
* Cadence - The resource-oriented smart contract programming language
*
* Copyright Dapper Labs, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package ast
type Walker interface {
Walk(element Element) Walker
}
// Walk traverses an AST in depth-first order:
// It starts by calling walker.Walk(element);
// If the returned walker is nil,
// child elements are not walked.
// If the returned walker is not-nil,
// then Walk is invoked recursively on this returned walker
// for each of the non-nil children of the element,
// followed by a call of Walk(nil) on the returned walker.
//
// The initial walker may not be nil.
func Walk(walker Walker, element Element) {
if walker = walker.Walk(element); walker == nil {
return
}
element.Walk(func(child Element) {
Walk(walker, child)
})
walker.Walk(nil)
}
func walkExpressions(walkChild func(Element), expressions []Expression) {
for _, expression := range expressions {
walkChild(expression)
}
}
func walkStatements(walkChild func(Element), statements []Statement) {
for _, statement := range statements {
walkChild(statement)
}
}
func walkDeclarations(walkChild func(Element), declarations []Declaration) {
for _, declaration := range declarations {
walkChild(declaration)
}
}