glob/glob.go

156 lines
2.3 KiB
Go

package glob
import (
"strings"
"fmt"
)
const (
Any = "*"
SuperAny = "**"
SingleAny = "?"
)
var Chars = []string{Any, SuperAny, SingleAny}
type Matcher interface {
Match(string) bool
}
func firstIndexOfChars(p string, any []string) (min int, c string) {
l := len(p)
min = l
weight := 0
for _, s := range any {
w := len(s)
i := strings.Index(p, s)
if i != -1 && i <= min && w > weight {
min = i
weight = w
c = s
}
}
if min == l {
return -1, ""
}
return
}
func parse(p string, m []Matcher, d []string) ([]Matcher, error) {
if len(p) == 0 {
return m, nil
}
i, c := firstIndexOfChars(p, Chars)
if i == -1 {
return append(m, raw{p}), nil
}
if i > 0 {
m = append(m, raw{p[0:i]})
}
switch c {
case SuperAny:
m = append(m, multiple{})
case Any:
m = append(m, multiple{d})
case SingleAny:
m = append(m, single{d})
}
return parse(p[i+len(c):], m, d)
}
func New(pattern string, d ...string) (Matcher, error) {
chunks, err := parse(pattern, nil, d)
if err != nil {
return nil, err
}
if len(chunks) == 1 {
return chunks[0], nil
}
return &composite{chunks}, nil
}
type raw struct {
s string
}
func (self raw) Match(s string) bool {
return self.s == s
}
func (self raw) String() string {
return fmt.Sprintf("[raw:%s]", self.s)
}
type multiple struct {
delimiters []string
}
func (self multiple) Match(s string) bool {
i, _ := firstIndexOfChars(s, self.delimiters)
return i == -1
}
func (self multiple) String() string {
return fmt.Sprintf("[multiple:%s]", self.delimiters)
}
type single struct {
delimiters []string
}
func (self single) Match(s string) bool {
if len(s) != 1 {
return false
}
i, _ := firstIndexOfChars(s, self.delimiters)
return i == -1
}
func (self single) String() string {
return fmt.Sprintf("[single:%s]", self.delimiters)
}
type composite struct {
chunks []Matcher
}
func (self composite) Match(m string) bool {
var prev Matcher
for _, c := range self.chunks {
if str, ok := c.(raw); ok {
i := strings.Index(m, str.s)
if i == -1 {
return false
}
l := len(str.s)
if prev != nil {
if !prev.Match(m[:i]) {
return false
}
prev = nil
}
m = m[i+l:]
continue
}
prev = c
}
if prev != nil {
return prev.Match(m)
}
return len(m) == 0
}