Generate tags from a lista without create new lists

tags.gotemplate.yml

{{- define "tags" }}
  {{- tmpl.Exec "tags_with_pt" (slice "" 0 .) }}
{{- end }}
{{- define "tags_with_pt" }}
  {{- $prefix := (index . 0)}}
  {{- $pt := (index . 1) }}
  {{- $items := (index . 2)}}
  {{- range $i, $item := $items }}
    {{- if ge $i $pt }}
      {{- if (eq (printf "%T" $item) "string") }}
        {{- $item = (slice $item)}}
      {{- end }}
      {{- range $value := $item }}
        {{- print "- " $prefix $value "\n" }}
        {{- $subprefix := (print $prefix $value "-")}}
        {{- $new_pt := (add $i 1)}}
        {{- tmpl.Exec "tags_with_pt" (slice $subprefix $new_pt $items) }}
      {{- end }}
    {{- end }}
  {{- end }}
{{- end }}

tags:
{{- $tags := (slice (slice "poseidon" "izi_api") "deploy" $env) }}
{{ tmpl.Exec "tags" $tags | strings.Indent 2 }}

tags_generate.js

const slice = (...args) => args;
const index = (args, i) => args[i];
const print = (...args) => args.join('');
const add   = (...args) => args.reduce((acc, v) => acc + v, 0);
const ge    = (a, b) => a >= b;

function tags(items) {
  return tags_with_pt(slice("", 0, items));
}

function tags_with_pt(args) {
  let prefix = index(args, 0);
  let pt = index(args, 1);
  let items = index(args, 2);

  items.map((item, i) => {
    if (ge(i, pt)) {
      if (typeof item == "string") {
        item = slice(item);
      }
      item.map((value) => {
        console.log(print("-", prefix, value));
        const subprefix = print(prefix, value, "-");
        const new_pt = add(i, 1);
        tags_with_pt(slice(subprefix, new_pt, items))
      })
    }
  });
}

tags([["poseidon", "izi-api"], ["deploy", "release", "test"], "prod"]);