43 lines
820 B
Go
43 lines
820 B
Go
package ast
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import "fmt"
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// Walk traverses an AST in depth-first order: It starts by calling fn(node);
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// node must not be nil. If f returns true, Walk invokes f recursively for
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// each of the non-nil children of node, followed by a call of f(nil).
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func Walk(node Node, fn func(Node) bool) {
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if !fn(node) {
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return
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}
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switch n := node.(type) {
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case *File:
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Walk(n.Node, fn)
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case *ObjectList:
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for _, item := range n.Items {
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Walk(item, fn)
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}
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case *ObjectKey:
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// nothing to do
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case *ObjectItem:
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for _, k := range n.Keys {
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Walk(k, fn)
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}
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Walk(n.Val, fn)
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case *LiteralType:
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// nothing to do
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case *ListType:
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for _, l := range n.List {
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Walk(l, fn)
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}
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case *ObjectType:
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for _, l := range n.List.Items {
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Walk(l, fn)
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}
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default:
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fmt.Printf(" unknown type: %T\n", n)
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}
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fn(nil)
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}
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