filter/helper.go
2017-08-30 22:01:19 +02:00

123 lines
2.4 KiB
Go

package filter
import (
"errors"
"reflect"
"strconv"
"strings"
)
const (
any = '*'
anys = string(any)
)
type less func(i, j int) bool
func reverse(f less) less {
return func(i, j int) bool {
return f(j, i)
}
}
func index(f Filter, i int, fields []string) (val reflect.Value) {
val = reflect.ValueOf(f.Index(i)).FieldByName(fields[0])
for j := 1; j < len(fields); j++ {
val = val.FieldByName(fields[j])
}
return
}
func makeLess(f Filter, fields []string) less {
switch index(f, 0, fields).Kind() {
case reflect.Int, reflect.Int8, reflect.Int16,
reflect.Int32, reflect.Int64:
return func(i, j int) bool { return index(f, i, fields).Int() < index(f, j, fields).Int() }
case reflect.Float32, reflect.Float64:
return func(i, j int) bool { return index(f, i, fields).Float() < index(f, j, fields).Float() }
case reflect.String:
return func(i, j int) bool { return index(f, i, fields).String() < index(f, j, fields).String() }
case reflect.Bool:
return func(i, _ int) bool { return index(f, i, fields).Bool() }
}
return nil
}
func getValue(v reflect.Value) (s string, b bool, err error) {
switch v.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16,
reflect.Int32, reflect.Int64:
s = strconv.FormatInt(v.Int(), 10)
case reflect.Float32, reflect.Float64:
s = strconv.FormatFloat(v.Float(), 'f', -1, 64)
case reflect.String:
s = v.String()
case reflect.Bool:
b = v.Bool()
default:
err = errors.New("nil")
}
return
}
func matchFunc(v string) func(string) bool {
vl := len(v)
switch {
case vl >= 3:
if v[0] == any && v[vl-1] == any && v[1] != any && v[vl-2] != any {
return func(s string) bool {
return strings.Contains(s, v[1:vl-1])
}
}
fallthrough
case vl >= 2:
switch {
case v[0] == any && v[1] != any:
return func(s string) bool {
return strings.HasSuffix(s, v[1:])
}
case v[vl-1] == any && v[vl-2] != any:
return func(s string) bool {
return strings.HasPrefix(s, v[:vl-1])
}
}
}
v = strings.Replace(v, anys+anys, anys, -1)
return func(s string) bool {
if s == v {
return true
}
return false
}
}
func ft(b bool) bool {
if b {
return true
}
return false
}
func ff(b bool) bool {
if !b {
return true
}
return false
}
func f(b bool) bool {
return false
}
func boolFunc(v string) func(bool) bool {
if len(v) == 0 {
return f
}
if v[0] == 't' {
return ft
}
if v[0] == 'f' {
return ff
}
return f
}