protected PoHeader::evaluatePlural($element_stack, $n)
Evaluate the plural element stack using a plural value.
Using an element stack, which represents a plural formula, we calculate which plural string should be used for a given plural value.
An example of plural formula parting and evaluation: Plural formula: 'n!=1' This formula is parsed by parseArithmetic() to a stack (array) of elements: array( 0 => '$n', 1 => '1', 2 => '!=', ); The evaluatePlural() method evaluates the $element_s