glob/glob.go

151 lines
2.3 KiB
Go

package glob
import (
"strings"
"fmt"
)
const (
any = "*"
superAny = "**"
singleAny = "?"
)
var chars = []string{any, superAny, singleAny}
// Glob represents compiled glob pattern.
type Glob interface {
Match(string) bool
}
// New creates Glob for given pattern and uses other given (if any) strings as delimiters.
func New(pattern string, d ...string) Glob {
chunks := parse(pattern, nil, strings.Join(d, ""))
if len(chunks) == 1 {
return chunks[0]
}
return &composite{chunks}
}
func parse(p string, m []Glob, d string) []Glob {
if len(p) == 0 {
return m
}
i, c := firstIndexOfChars(p, chars)
if i == -1 {
return append(m, raw{p})
}
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)
}
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 {
return strings.IndexAny(s, self.delimiters) == -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 {
return len(s) == 1 && strings.IndexAny(s, self.delimiters) == -1
}
func (self single) String() string {
return fmt.Sprintf("[single:%s]", self.delimiters)
}
type composite struct {
chunks []Glob
}
func (self composite) Match(m string) bool {
var prev Glob
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
}
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
}