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|
# encoding: utf-8
require 'thread_safe'
module ActionDispatch
module Journey # :nodoc:
module Visitors # :nodoc:
class Visitor # :nodoc:
DISPATCH_CACHE = ThreadSafe::Cache.new { |h,k|
h[k] = :"visit_#{k}"
}
def accept(node)
visit(node)
end
private
def visit node
send(DISPATCH_CACHE[node.type], node)
end
def binary(node)
visit(node.left)
visit(node.right)
end
def visit_CAT(n); binary(n); end
def nary(node)
node.children.each { |c| visit(c) }
end
def visit_OR(n); nary(n); end
def unary(node)
visit(node.left)
end
def visit_GROUP(n); unary(n); end
def visit_STAR(n); unary(n); end
def terminal(node); end
%w{ LITERAL SYMBOL SLASH DOT }.each do |t|
class_eval %{ def visit_#{t}(n); terminal(n); end }, __FILE__, __LINE__
end
end
# Loop through the requirements AST
class Each < Visitor # :nodoc:
attr_reader :block
def initialize(block)
@block = block
end
def visit(node)
super
block.call(node)
end
end
class String < Visitor # :nodoc:
private
def binary(node)
[visit(node.left), visit(node.right)].join
end
def nary(node)
node.children.map { |c| visit(c) }.join '|'
end
def terminal(node)
node.left
end
def visit_GROUP(node)
"(#{visit(node.left)})"
end
end
class OptimizedPath < Visitor # :nodoc:
def accept(node)
Array(visit(node))
end
private
def visit_CAT(node)
[visit(node.left), visit(node.right)].flatten
end
def visit_SYMBOL(node)
node.left[1..-1].to_sym
end
def visit_STAR(node)
visit(node.left)
end
def visit_GROUP(node)
[]
end
%w{ LITERAL SLASH DOT }.each do |t|
class_eval %{ def visit_#{t}(n); n.left; end }, __FILE__, __LINE__
end
end
# Used for formatting urls (url_for)
class Formatter < Visitor # :nodoc:
attr_reader :options
def initialize(options)
@options = options
end
private
def escape_path(value)
Router::Utils.escape_path(value)
end
def escape_segment(value)
Router::Utils.escape_segment(value)
end
def visit(node, optional = false)
case node.type
when :LITERAL, :SLASH, :DOT
node.left
when :STAR
visit_STAR(node.left)
when :GROUP
visit(node.left, true)
when :CAT
visit_CAT(node, optional)
when :SYMBOL
visit_SYMBOL(node, node.to_sym)
end
end
def visit_CAT(node, optional)
left = visit(node.left, optional)
right = visit(node.right, optional)
if optional && !(right && left)
""
else
[left, right].join
end
end
def visit_STAR(node)
if value = options[node.to_sym]
escape_path(value)
end
end
def visit_SYMBOL(node, name)
if value = options[name]
name == :controller ? escape_path(value) : escape_segment(value)
end
end
end
class Dot < Visitor # :nodoc:
def initialize
@nodes = []
@edges = []
end
def accept(node)
super
<<-eodot
digraph parse_tree {
size="8,5"
node [shape = none];
edge [dir = none];
#{@nodes.join "\n"}
#{@edges.join("\n")}
}
eodot
end
private
def binary(node)
node.children.each do |c|
@edges << "#{node.object_id} -> #{c.object_id};"
end
super
end
def nary(node)
node.children.each do |c|
@edges << "#{node.object_id} -> #{c.object_id};"
end
super
end
def unary(node)
@edges << "#{node.object_id} -> #{node.left.object_id};"
super
end
def visit_GROUP(node)
@nodes << "#{node.object_id} [label=\"()\"];"
super
end
def visit_CAT(node)
@nodes << "#{node.object_id} [label=\"○\"];"
super
end
def visit_STAR(node)
@nodes << "#{node.object_id} [label=\"*\"];"
super
end
def visit_OR(node)
@nodes << "#{node.object_id} [label=\"|\"];"
super
end
def terminal(node)
value = node.left
@nodes << "#{node.object_id} [label=\"#{value}\"];"
end
end
end
end
end
|
