go/ast/inspector: fix misnomer in callback signature

Invert callback return value name from "prune" to "proceed". As
documented, returning true from the callback causes Nodes and
WithStack to continue searching children, not to prune.

Change-Id: I4c10b0edfec507dcf947d47076e537ffa7f1a3f5
Reviewed-on: https://go-review.googlesource.com/c/tools/+/212222
Run-TryBot: Muir Manders <muir@mnd.rs>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>
diff --git a/go/ast/inspector/inspector.go b/go/ast/inspector/inspector.go
index ddbdd3f..3084508 100644
--- a/go/ast/inspector/inspector.go
+++ b/go/ast/inspector/inspector.go
@@ -90,7 +90,7 @@
 // The types argument, if non-empty, enables type-based filtering of
 // events. The function f if is called only for nodes whose type
 // matches an element of the types slice.
-func (in *Inspector) Nodes(types []ast.Node, f func(n ast.Node, push bool) (prune bool)) {
+func (in *Inspector) Nodes(types []ast.Node, f func(n ast.Node, push bool) (proceed bool)) {
 	mask := maskOf(types)
 	for i := 0; i < len(in.events); {
 		ev := in.events[i]
@@ -114,7 +114,7 @@
 // supplies each call to f an additional argument, the current
 // traversal stack. The stack's first element is the outermost node,
 // an *ast.File; its last is the innermost, n.
-func (in *Inspector) WithStack(types []ast.Node, f func(n ast.Node, push bool, stack []ast.Node) (prune bool)) {
+func (in *Inspector) WithStack(types []ast.Node, f func(n ast.Node, push bool, stack []ast.Node) (proceed bool)) {
 	mask := maskOf(types)
 	var stack []ast.Node
 	for i := 0; i < len(in.events); {