update

Signed-off-by: hongming <talonwan@yunify.com>

vendor/github.com/open-policy-agent/opa/ast/pretty.go

@@ -0,0 +1,82 @@
+// Copyright 2018 The OPA Authors.  All rights reserved.
+// Use of this source code is governed by an Apache2
+// license that can be found in the LICENSE file.
+
+package ast
+
+import (
+	"fmt"
+	"io"
+	"strings"
+)
+
+// Pretty writes a pretty representation of the AST rooted at x to w.
+//
+// This is function is intended for debug purposes when inspecting ASTs.
+func Pretty(w io.Writer, x interface{}) {
+	pp := &prettyPrinter{
+		depth: -1,
+		w:     w,
+	}
+	NewBeforeAfterVisitor(pp.Before, pp.After).Walk(x)
+}
+
+type prettyPrinter struct {
+	depth int
+	w     io.Writer
+}
+
+func (pp *prettyPrinter) Before(x interface{}) bool {
+	switch x.(type) {
+	case *Term:
+	default:
+		pp.depth++
+	}
+
+	switch x := x.(type) {
+	case *Term:
+		return false
+	case Args:
+		if len(x) == 0 {
+			return false
+		}
+		pp.writeType(x)
+	case *Expr:
+		extras := []string{}
+		if x.Negated {
+			extras = append(extras, "negated")
+		}
+		extras = append(extras, fmt.Sprintf("index=%d", x.Index))
+		pp.writeIndent("%v %v", TypeName(x), strings.Join(extras, " "))
+	case Null, Boolean, Number, String, Var:
+		pp.writeValue(x)
+	default:
+		pp.writeType(x)
+	}
+	return false
+}
+
+func (pp *prettyPrinter) After(x interface{}) {
+	switch x.(type) {
+	case *Term:
+	default:
+		pp.depth--
+	}
+}
+
+func (pp *prettyPrinter) writeValue(x interface{}) {
+	pp.writeIndent(fmt.Sprint(x))
+}
+
+func (pp *prettyPrinter) writeType(x interface{}) {
+	pp.writeIndent(TypeName(x))
+}
+
+func (pp *prettyPrinter) writeIndent(f string, a ...interface{}) {
+	pad := strings.Repeat(" ", pp.depth)
+	pp.write(pad+f, a...)
+}
+
+func (pp *prettyPrinter) write(f string, a ...interface{}) {
+	fmt.Fprintf(pp.w, f+"\n", a...)
+}