You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
80 lines
2.5 KiB
80 lines
2.5 KiB
// Copyright 2019 PingCAP, 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,
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package texttree
|
|
|
|
const (
|
|
// TreeBody indicates the current operator sub-tree is not finished, still
|
|
// has child operators to be attached on.
|
|
TreeBody = '│'
|
|
// TreeMiddleNode indicates this operator is not the last child of the
|
|
// current sub-tree rooted by its parent.
|
|
TreeMiddleNode = '├'
|
|
// TreeLastNode indicates this operator is the last child of the current
|
|
// sub-tree rooted by its parent.
|
|
TreeLastNode = '└'
|
|
// TreeGap is used to represent the gap between the branches of the tree.
|
|
TreeGap = ' '
|
|
// TreeNodeIdentifier is used to replace the treeGap once we need to attach
|
|
// a node to a sub-tree.
|
|
TreeNodeIdentifier = '─'
|
|
)
|
|
|
|
// Indent4Child appends more blank to the `indent` string
|
|
func Indent4Child(indent string, isLastChild bool) string {
|
|
if !isLastChild {
|
|
return string(append([]rune(indent), TreeBody, TreeGap))
|
|
}
|
|
|
|
// If the current node is the last node of the current operator tree, we
|
|
// need to end this sub-tree by changing the closest treeBody to a treeGap.
|
|
indentBytes := []rune(indent)
|
|
for i := len(indentBytes) - 1; i >= 0; i-- {
|
|
if indentBytes[i] == TreeBody {
|
|
indentBytes[i] = TreeGap
|
|
break
|
|
}
|
|
}
|
|
|
|
return string(append(indentBytes, TreeBody, TreeGap))
|
|
}
|
|
|
|
// PrettyIdentifier returns a pretty identifier which contains indent and tree node hierarchy indicator
|
|
func PrettyIdentifier(id, indent string, isLastChild bool) string {
|
|
if len(indent) == 0 {
|
|
return id
|
|
}
|
|
|
|
indentBytes := []rune(indent)
|
|
for i := len(indentBytes) - 1; i >= 0; i-- {
|
|
if indentBytes[i] != TreeBody {
|
|
continue
|
|
}
|
|
|
|
// Here we attach a new node to the current sub-tree by changing
|
|
// the closest treeBody to a:
|
|
// 1. treeLastNode, if this operator is the last child.
|
|
// 2. treeMiddleNode, if this operator is not the last child..
|
|
if isLastChild {
|
|
indentBytes[i] = TreeLastNode
|
|
} else {
|
|
indentBytes[i] = TreeMiddleNode
|
|
}
|
|
break
|
|
}
|
|
|
|
// Replace the treeGap between the treeBody and the node to a
|
|
// treeNodeIdentifier.
|
|
indentBytes[len(indentBytes)-1] = TreeNodeIdentifier
|
|
return string(indentBytes) + id
|
|
}
|
|
|