elves/elvish

package filter

import (
    "regexp"
    "strings"
)

// Filter represents a compiled filter, which can be used to match text.
type Filter interface {
    Match(s string) bool
}

type andFilter struct {
    queries []Filter
}

func (aq andFilter) Match(s string) bool {
    for _, q := range aq.queries {
        if !q.Match(s) {
            return false
        }
    }
    return true
}

type orFilter struct {
    queries []Filter
}

func (oq orFilter) Match(s string) bool {
    for _, q := range oq.queries {
        if q.Match(s) {
            return true
        }
    }
    return false
}

type substringFilter struct {
    pattern    string
    ignoreCase bool
}

func (sq substringFilter) Match(s string) bool {
    if sq.ignoreCase {
        s = strings.ToLower(s)
    }
    return strings.Contains(s, sq.pattern)
}

type regexpFilter struct {
    pattern *regexp.Regexp
}

func (rq regexpFilter) Match(s string) bool {
    return rq.pattern.MatchString(s)
}