xpath/main_test.go
2020-09-21 16:15:14 +08:00

189 lines
3.1 KiB
Go

package main
import (
"strings"
"testing"
)
// type Type int
// const (
// TypeUnknown Type = iota
// TypeNode
// TypeText
// TypeAttribute
// )
// // type Attribute struct {
// // Name []rune
// // Value []rune
// // }
// type Node struct {
// Parent *Node
// Children []*Node
// Attributes []*Node
// Name []rune
// Value []rune
// Type Type
// }
type Selection int
const (
SelUnknown Selection = iota
SelRoot // 根节点
SelSelf // 自身
SelParent // 父节点
SelChildren // 孩子
SelAllChildRen // 所有子孙
SelMethod // 函数类型
SelAttribute // 属性
)
type Predicates struct {
Name []rune
}
type Node struct {
Name []rune
Value []rune
Next *Node
Sel Selection
Pred Predicates
}
func compile(spath string) (head *Node, tail *Node) {
var path []rune = []rune(strings.TrimSpace(spath))
path = append(path, ' ')
var cur *Node
if path[0] == '/' {
head = &Node{}
head.Sel = SelRoot
head.Next = cur
} else {
head = cur
}
// for i := 0; i < len(spath); i++ {
var i = 0
c := path[i]
switch c {
case '/':
if path[i+1] == '/' {
i++
head.Sel = SelAllChildRen
} else {
head.Sel = SelChildren
}
case '.':
head.Sel = SelSelf
case '(':
// 进入递归
i++
start, end := getBrackets(path, len(spath), &i)
h, t := compile(string(path[start:end]))
cur.Next = h
cur = t
case '|':
// 递归
default:
head.Sel = SelUnknown
}
return head, cur
}
func getAxes(path []rune, limit int, ii *int, cur *Node) {
i := *ii
for ; i < limit; i++ {
c := path[i]
switch c {
case '[':
case '/':
case '@': //
cur.Sel = SelAttribute
cur.Name = getAttributeName(path, limit, ii)
case '.': // 获取节点
if path[i+1] == '.' {
i++
cur.Sel = SelParent
} else {
cur.Sel = SelSelf
}
return
case '(': // function
s, e := getBrackets(path, limit, ii)
cur.Value = path[s:e]
cur.Sel = SelMethod
return
default:
cur.Name = append(cur.Name, c)
}
}
}
func getAttributeName(path []rune, limit int, ii *int) []rune {
i := *ii
for start := i; i < limit; i++ {
if c, ok := Escape(path, &i); !ok {
switch {
case c >= ' ' && c <= '/':
fallthrough
case c >= ':' && c <= '@':
fallthrough
case c >= '[' && c <= '`':
fallthrough
case c >= '{' && c <= '~':
return path[start:i]
default:
panic("get attribute error")
}
}
}
panic("get attribute error")
}
func getBrackets(path []rune, limit int, ii *int) (start int, end int) {
i := *ii
open := 1
for start := i; i < limit; i++ {
if c, ok := Escape(path, &i); !ok {
switch c {
case '(':
open++
case ')':
open--
}
if open == 0 {
return start, i
}
}
}
panic("can't find ')' close?")
}
// Escape
func Escape(data []rune, i *int) (rune, bool) {
if data[*i] == '\\' {
*i++
return data[*i], true
}
return data[*i], false
}
func TestMain(t *testing.T) {
// t.Error(xPath("/a/../../b/../c//.//"))
// t.Error(xPath("/a/./b/../../c/"))
// t.Error(xPath("/"))
// t.Error(xPath("/a/./b/../../c/"))
// t.Error(xPath("/a//b////c/d//././/.."))
}