$s := slice "hello" "world"

apply $s "strings.FirstUpper" "." -> [%!t(string=Hello) %!t(string=World)]
apply $s "add" "." ", five" -> [%!t(string=hello, five) %!t(string=world, five)]

not "hello" -> false
len "hello" -> %!t(int=5)

apply (slice "hello) "not" "." 
apply (slice "hello) "len" "." 

Error: error building site: render: failed to render pages:
  render of "C:/_repos/github/clone/issue-2906-return-values/content/_index.md" failed:
  "C:\_repos\github\clone\issue-2906-return-values\layouts\_default\home.html:20:17":
  execute of template failed: template: _default/home.html:20:17: 
  executing "main" at <apply (slice "hello") "not" ".">: 
  error calling apply: called apply using string as type reflect.Value