Second, improving back button behavior is a matter of 
  setting all the right nocache attributes. If you use forms, 
  you're likely to have trouble with back navigation no matter 
  what you do ("The page contains expired POST data").

Paul calls Prolog pattern matching great for writing basic list manipulation functions, then downhill from there. But if you're looking at those kinds of toy problems (how do you write reduce?) you get a biased sample.

Really, you have to try writing something representative of your problem space. And that code snippet is not at all representative of my experience writing web applications; it lacks:

  * Persistent storage
  * Large pages with multiple possible forms and actions
  * Javascript
  * Caching
  * Complicated queries
  * Pagination

  def said
    if request.method == :post
      session[:said] = params[:said]
      render :action => "clickhere"
    else
      render :action => "result" if session[:said]
    end
  end

  default template said.rhtml:
  <% form_tag do %><%= text_field_tag "said", "" %><%= submit_tag %><% end %>

  clickhere.rhtml:
  <%= link_to "click here", "" %>
  
  result.rhtml:
  You said <%= session[:said] %>

here's a ruby version a bit closer to the original. there's a bunch of support and then process roughly corresponds to said above

  #!/usr/bin/env ruby
  require 'rubygems'
  require 'mongrel'

  class FooHandler < Mongrel::HttpHandler
  
    def initialize
      @fnids = {}
      @c = 0
    end
  
    def new_fnid(proc)
      @c += 1
      @fnids[@c] = proc
      @c
    end
  
    def query_params(request)
      request.class.query_parse(request.params['QUERY_STRING'])
    end
  
    def pr(response, html)    
      response.start do |head,out|
        head["Content-Type"] = "text/html"
        out << html
      end
    end
  
    def w_link(response, link_text, &block)
      c = new_fnid(block)
      pr(response, "<a href='?fnid=#{c}'>#{link_text}</a>")
    end
  
    def aform(response, form_html, &block)
      c = new_fnid(block)
      pr(response, "<form><input type='hidden' name='fnid' value='#{c}'>#{form_html}</form>")
    end
  
    def process(request, response)
      if (fnid = query_params(request)['fnid'])
        @fnids[fnid.to_i].call(request, response)
      else
        aform(response, "<input name='foo'><input type='submit'>") do |req1, resp1|
          w_link(resp1, "click here") do |req2, resp2|
            pr(resp2, "you said: " + query_params(req1)['foo'])
          end
        end
      end
    end
  end

  Mongrel::Configurator.new :port => 8080 do
    listener {uri "/", :handler => FooHandler.new}
    trap("INT") {stop}
    run
  end.join

In 1.9, it's moving towards Python: "foo"[0] == "f"

  (table name-key name age-key age)