# File lib/math_ml/latex.rb, line 320 def expand_environment(env, body, params, opt=nil) return nil unless @environments.has_key?(env) e = @environments[env] opt = e.option if e.option && !opt params.unshift(opt) if e.option raise ParseError.new("Need more parameter.") if params.size < e.num bg = e.beginning.gsub(/(#{MBEC}*?)\#(\d+)/) do $1.to_s << params[$2.to_i-1] end en = e.ending.gsub(/(#{MBEC}*?)\#(\d+)/) do $1.to_s << params[$2.to_i-1] end " #{bg} #{body} #{en} " end