pattern name generator

name_gen.go

package main

import (
	"fmt"
	"path"
)

type StringGenerator interface {
	Next() bool
	Get() string
}

type NameGen struct {
	basePath   string
	baseFile   string
	start      int // [start, end)
	end        int
	num        int
	withoutIdx bool
	current    string
}

func NewNameGen(base, file string, start, num int, withoutIdx bool) *NameGen {
	return &NameGen{base, file, start, start + num, num, withoutIdx, ""}
}

func (n *NameGen) Next() bool {
	if n.withoutIdx {
		n.current = path.Join(n.basePath, fmt.Sprintf("%s.jpeg", n.baseFile))
		n.withoutIdx = false
		return true
	}
	if n.start < n.end {
		n.current = path.Join(n.basePath, fmt.Sprintf("%s_%d.jpeg", n.baseFile, n.start))
		n.start = n.start + 1
		return true
	}
	return false
}

func (n *NameGen) Has() bool {
	return len(n.current) > 0
}

func (n *NameGen) Get() string {
	return n.current
}

func main() {
	fmt.Println("Hello, playground")
	var g StringGenerator = NewNameGen("/usr", "name", 0, 5, true)
	for g.Next() {
		fmt.Println(g.Get())
	}
}