ntool/narr/util.go

package narr

import (
	"git.noahlan.cn/noahlan/ntool/ndef"
	"git.noahlan.cn/noahlan/ntool/nrandom"
	"strings"
)

// Reverse string slice [site user info 0] -> [0 info user site]
func Reverse(ss []string) {
	ln := len(ss)
	for i := 0; i < ln/2; i++ {
		li := ln - i - 1
		ss[i], ss[li] = ss[li], ss[i]
	}
}

// StringsRemove a value form a string slice
func StringsRemove(ss []string, s string) []string {
	ns := make([]string, 0, len(ss))
	for _, v := range ss {
		if v != s {
			ns = append(ns, v)
		}
	}
	return ns
}

// StringsFilter given strings, default will filter emtpy string.
//
// Usage:
//
//	// output: [a, b]
//	ss := narr.StringsFilter([]string{"a", "", "b", ""})
func StringsFilter(ss []string, filter ...func(s string) bool) []string {
	var fn func(s string) bool
	if len(filter) > 0 && filter[0] != nil {
		fn = filter[0]
	} else {
		fn = func(s string) bool {
			return s != ""
		}
	}

	ns := make([]string, 0, len(ss))
	for _, s := range ss {
		if fn(s) {
			ns = append(ns, s)
		}
	}
	return ns
}

// StringsMap handle each string item, map to new strings
func StringsMap(ss []string, mapFn func(s string) string) []string {
	ns := make([]string, 0, len(ss))
	for _, s := range ss {
		ns = append(ns, mapFn(s))
	}
	return ns
}

// TrimStrings trim string slice item.
//
// Usage:
//
//	// output: [a, b, c]
//	ss := narr.TrimStrings([]string{",a", "b.", ",.c,"}, ",.")
func TrimStrings(ss []string, cutSet ...string) []string {
	cutSetLn := len(cutSet)
	hasCutSet := cutSetLn > 0 && cutSet[0] != ""

	var trimSet string
	if hasCutSet {
		trimSet = cutSet[0]
	}
	if cutSetLn > 1 {
		trimSet = strings.Join(cutSet, "")
	}

	ns := make([]string, 0, len(ss))
	for _, str := range ss {
		if hasCutSet {
			ns = append(ns, strings.Trim(str, trimSet))
		} else {
			ns = append(ns, strings.TrimSpace(str))
		}
	}
	return ns
}

// GetRandomOne get random element from an array/slice
func GetRandomOne[T any](arr []T) T { return RandomOne(arr) }

// RandomOne get random element from an array/slice
func RandomOne[T any](arr []T) T {
	if ln := len(arr); ln > 0 {
		i := nrandom.RandInt(0, len(arr))
		return arr[i]
	}
	panic("cannot get value from nil or empty slice")
}

// Unique value in the given slice data.
func Unique[T ~string | ndef.XIntOrFloat](list []T) []T {
	if len(list) < 2 {
		return list
	}

	valMap := make(map[T]struct{}, len(list))
	uniArr := make([]T, 0, len(list))

	for _, t := range list {
		if _, ok := valMap[t]; !ok {
			valMap[t] = struct{}{}
			uniArr = append(uniArr, t)
		}
	}
	return uniArr
}

// IndexOf value in given slice.
func IndexOf[T ~string | ndef.XIntOrFloat](val T, list []T) int {
	for i, v := range list {
		if v == val {
			return i
		}
	}
	return -1
}