class Mustache::Context

def fetch(name, default = :__raise)

set to true), will raise a ContextMiss exception on miss.
If no second parameter is passed (or raise_on_context_miss is

second parameter.
stack. You may specify the default return value by passing a
Similar to Hash#fetch, finds a value by `name` in the context's 
def fetch(name, default = :__raise)
  @stack.each do |frame|
    # Prevent infinite recursion.
    next if frame == self
    value = find(frame, name, :__missing)
    return value if :__missing != value
  end
  if default == :__raise || mustache_in_stack.raise_on_context_miss?
    raise ContextMiss.new("Can't find #{name} in #{@stack.inspect}")
  else
    default
  end
end