youtubebeat/vendor/github.com/antchfx/xpath/func.go

475 lines
10 KiB
Go

package xpath
import (
"errors"
"fmt"
"math"
"strconv"
"strings"
)
// The XPath function list.
func predicate(q query) func(NodeNavigator) bool {
type Predicater interface {
Test(NodeNavigator) bool
}
if p, ok := q.(Predicater); ok {
return p.Test
}
return func(NodeNavigator) bool { return true }
}
// positionFunc is a XPath Node Set functions position().
func positionFunc(q query, t iterator) interface{} {
var (
count = 1
node = t.Current()
)
test := predicate(q)
for node.MoveToPrevious() {
if test(node) {
count++
}
}
return float64(count)
}
// lastFunc is a XPath Node Set functions last().
func lastFunc(q query, t iterator) interface{} {
var (
count = 0
node = t.Current()
)
node.MoveToFirst()
test := predicate(q)
for {
if test(node) {
count++
}
if !node.MoveToNext() {
break
}
}
return float64(count)
}
// countFunc is a XPath Node Set functions count(node-set).
func countFunc(q query, t iterator) interface{} {
var count = 0
test := predicate(q)
switch typ := q.Evaluate(t).(type) {
case query:
for node := typ.Select(t); node != nil; node = typ.Select(t) {
if test(node) {
count++
}
}
}
return float64(count)
}
// sumFunc is a XPath Node Set functions sum(node-set).
func sumFunc(q query, t iterator) interface{} {
var sum float64
switch typ := q.Evaluate(t).(type) {
case query:
for node := typ.Select(t); node != nil; node = typ.Select(t) {
if v, err := strconv.ParseFloat(node.Value(), 64); err == nil {
sum += v
}
}
case float64:
sum = typ
case string:
v, err := strconv.ParseFloat(typ, 64)
if err != nil {
panic(errors.New("sum() function argument type must be a node-set or number"))
}
sum = v
}
return sum
}
func asNumber(t iterator, o interface{}) float64 {
switch typ := o.(type) {
case query:
node := typ.Select(t)
if node == nil {
return float64(0)
}
if v, err := strconv.ParseFloat(node.Value(), 64); err == nil {
return v
}
case float64:
return typ
case string:
v, err := strconv.ParseFloat(typ, 64)
if err != nil {
panic(errors.New("ceiling() function argument type must be a node-set or number"))
}
return v
}
return 0
}
// ceilingFunc is a XPath Node Set functions ceiling(node-set).
func ceilingFunc(q query, t iterator) interface{} {
val := asNumber(t, q.Evaluate(t))
return math.Ceil(val)
}
// floorFunc is a XPath Node Set functions floor(node-set).
func floorFunc(q query, t iterator) interface{} {
val := asNumber(t, q.Evaluate(t))
return math.Floor(val)
}
// roundFunc is a XPath Node Set functions round(node-set).
func roundFunc(q query, t iterator) interface{} {
val := asNumber(t, q.Evaluate(t))
//return math.Round(val)
return round(val)
}
// nameFunc is a XPath functions name([node-set]).
func nameFunc(q query, t iterator) interface{} {
v := q.Select(t)
if v == nil {
return ""
}
ns := v.Prefix()
if ns == "" {
return v.LocalName()
}
return ns + ":" + v.LocalName()
}
// localNameFunc is a XPath functions local-name([node-set]).
func localNameFunc(q query, t iterator) interface{} {
v := q.Select(t)
if v == nil {
return ""
}
return v.LocalName()
}
// namespaceFunc is a XPath functions namespace-uri([node-set]).
func namespaceFunc(q query, t iterator) interface{} {
v := q.Select(t)
if v == nil {
return ""
}
return v.Prefix()
}
func asBool(t iterator, v interface{}) bool {
switch v := v.(type) {
case nil:
return false
case *NodeIterator:
return v.MoveNext()
case bool:
return bool(v)
case float64:
return v != 0
case string:
return v != ""
case query:
return v.Select(t) != nil
default:
panic(fmt.Errorf("unexpected type: %T", v))
}
}
func asString(t iterator, v interface{}) string {
switch v := v.(type) {
case nil:
return ""
case bool:
if v {
return "true"
}
return "false"
case float64:
return strconv.FormatFloat(v, 'g', -1, 64)
case string:
return v
case query:
node := v.Select(t)
if node == nil {
return ""
}
return node.Value()
default:
panic(fmt.Errorf("unexpected type: %T", v))
}
}
// booleanFunc is a XPath functions boolean([node-set]).
func booleanFunc(q query, t iterator) interface{} {
v := q.Evaluate(t)
return asBool(t, v)
}
// numberFunc is a XPath functions number([node-set]).
func numberFunc(q query, t iterator) interface{} {
v := q.Evaluate(t)
return asNumber(t, v)
}
// stringFunc is a XPath functions string([node-set]).
func stringFunc(q query, t iterator) interface{} {
v := q.Evaluate(t)
return asString(t, v)
}
// startwithFunc is a XPath functions starts-with(string, string).
func startwithFunc(arg1, arg2 query) func(query, iterator) interface{} {
return func(q query, t iterator) interface{} {
var (
m, n string
ok bool
)
switch typ := arg1.Evaluate(t).(type) {
case string:
m = typ
case query:
node := typ.Select(t)
if node == nil {
return false
}
m = node.Value()
default:
panic(errors.New("starts-with() function argument type must be string"))
}
n, ok = arg2.Evaluate(t).(string)
if !ok {
panic(errors.New("starts-with() function argument type must be string"))
}
return strings.HasPrefix(m, n)
}
}
// endwithFunc is a XPath functions ends-with(string, string).
func endwithFunc(arg1, arg2 query) func(query, iterator) interface{} {
return func(q query, t iterator) interface{} {
var (
m, n string
ok bool
)
switch typ := arg1.Evaluate(t).(type) {
case string:
m = typ
case query:
node := typ.Select(t)
if node == nil {
return false
}
m = node.Value()
default:
panic(errors.New("ends-with() function argument type must be string"))
}
n, ok = arg2.Evaluate(t).(string)
if !ok {
panic(errors.New("ends-with() function argument type must be string"))
}
return strings.HasSuffix(m, n)
}
}
// containsFunc is a XPath functions contains(string or @attr, string).
func containsFunc(arg1, arg2 query) func(query, iterator) interface{} {
return func(q query, t iterator) interface{} {
var (
m, n string
ok bool
)
switch typ := arg1.Evaluate(t).(type) {
case string:
m = typ
case query:
node := typ.Select(t)
if node == nil {
return false
}
m = node.Value()
default:
panic(errors.New("contains() function argument type must be string"))
}
n, ok = arg2.Evaluate(t).(string)
if !ok {
panic(errors.New("contains() function argument type must be string"))
}
return strings.Contains(m, n)
}
}
// normalizespaceFunc is XPath functions normalize-space(string?)
func normalizespaceFunc(q query, t iterator) interface{} {
var m string
switch typ := q.Evaluate(t).(type) {
case string:
m = typ
case query:
node := typ.Select(t)
if node == nil {
return false
}
m = node.Value()
}
return strings.TrimSpace(m)
}
// substringFunc is XPath functions substring function returns a part of a given string.
func substringFunc(arg1, arg2, arg3 query) func(query, iterator) interface{} {
return func(q query, t iterator) interface{} {
var m string
switch typ := arg1.Evaluate(t).(type) {
case string:
m = typ
case query:
node := typ.Select(t)
if node == nil {
return ""
}
m = node.Value()
}
var start, length float64
var ok bool
if start, ok = arg2.Evaluate(t).(float64); !ok {
panic(errors.New("substring() function first argument type must be int"))
} else if start < 1 {
panic(errors.New("substring() function first argument type must be >= 1"))
}
start--
if arg3 != nil {
if length, ok = arg3.Evaluate(t).(float64); !ok {
panic(errors.New("substring() function second argument type must be int"))
}
}
if (len(m) - int(start)) < int(length) {
panic(errors.New("substring() function start and length argument out of range"))
}
if length > 0 {
return m[int(start):int(length+start)]
}
return m[int(start):]
}
}
// substringIndFunc is XPath functions substring-before/substring-after function returns a part of a given string.
func substringIndFunc(arg1, arg2 query, after bool) func(query, iterator) interface{} {
return func(q query, t iterator) interface{} {
var str string
switch v := arg1.Evaluate(t).(type) {
case string:
str = v
case query:
node := v.Select(t)
if node == nil {
return ""
}
str = node.Value()
}
var word string
switch v := arg2.Evaluate(t).(type) {
case string:
word = v
case query:
node := v.Select(t)
if node == nil {
return ""
}
word = node.Value()
}
if word == "" {
return ""
}
i := strings.Index(str, word)
if i < 0 {
return ""
}
if after {
return str[i+len(word):]
}
return str[:i]
}
}
// stringLengthFunc is XPATH string-length( [string] ) function that returns a number
// equal to the number of characters in a given string.
func stringLengthFunc(arg1 query) func(query, iterator) interface{} {
return func(q query, t iterator) interface{} {
switch v := arg1.Evaluate(t).(type) {
case string:
return float64(len(v))
case query:
node := v.Select(t)
if node == nil {
break
}
return float64(len(node.Value()))
}
return float64(0)
}
}
// translateFunc is XPath functions translate() function returns a replaced string.
func translateFunc(arg1, arg2, arg3 query) func(query, iterator) interface{} {
return func(q query, t iterator) interface{} {
str := asString(t, arg1.Evaluate(t))
src := asString(t, arg2.Evaluate(t))
dst := asString(t, arg3.Evaluate(t))
var replace []string
for i, s := range src {
d := ""
if i < len(dst) {
d = string(dst[i])
}
replace = append(replace, string(s), d)
}
return strings.NewReplacer(replace...).Replace(str)
}
}
// notFunc is XPATH functions not(expression) function operation.
func notFunc(q query, t iterator) interface{} {
switch v := q.Evaluate(t).(type) {
case bool:
return !v
case query:
node := v.Select(t)
return node == nil
default:
return false
}
}
// concatFunc is the concat function concatenates two or more
// strings and returns the resulting string.
// concat( string1 , string2 [, stringn]* )
func concatFunc(args ...query) func(query, iterator) interface{} {
return func(q query, t iterator) interface{} {
var a []string
for _, v := range args {
switch v := v.Evaluate(t).(type) {
case string:
a = append(a, v)
case query:
node := v.Select(t)
if node != nil {
a = append(a, node.Value())
}
}
}
return strings.Join(a, "")
}
}