Extract key names using Mustache Ruby API?

Question

Does the Ruby Mustache API have a way to return the key names from a template?

Take, for example:

require 'mustache'
m = Mustache.new
m.template = "Hello {{first_name}} {{last_name}}"

I want to make an API call -- but I don't know what it is -- that returns the key names:

[:first_name, :last_name]

or something similar.

Answer 1

There isn't a way specifically to do that, but as a start you might consider the following:

>> pp Mustache::Template.new('Hello {{first_name}} {{person.last_name}}').tokens
[:multi,
 [:static, "Hello "],
 [:mustache, :etag, [:mustache, :fetch, ["first_name"]]],
 [:static, " "],
 [:mustache, :etag, [:mustache, :fetch, ["person", "last_name"]]]]

It should be fairly easy to write a traversal that extracted the relevant keys.