diff options
Diffstat (limited to 'actionpack/lib/action_dispatch/journey/visitors.rb')
| -rw-r--r-- | actionpack/lib/action_dispatch/journey/visitors.rb | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/actionpack/lib/action_dispatch/journey/visitors.rb b/actionpack/lib/action_dispatch/journey/visitors.rb new file mode 100644 index 0000000000..d2619cbf3a --- /dev/null +++ b/actionpack/lib/action_dispatch/journey/visitors.rb @@ -0,0 +1,268 @@ +# frozen_string_literal: true + +module ActionDispatch + # :stopdoc: + module Journey + class Format + ESCAPE_PATH = ->(value) { Router::Utils.escape_path(value) } + ESCAPE_SEGMENT = ->(value) { Router::Utils.escape_segment(value) } + + Parameter = Struct.new(:name, :escaper) do + def escape(value); escaper.call value; end + end + + def self.required_path(symbol) + Parameter.new symbol, ESCAPE_PATH + end + + def self.required_segment(symbol) + Parameter.new symbol, ESCAPE_SEGMENT + end + + def initialize(parts) + @parts = parts + @children = [] + @parameters = [] + + parts.each_with_index do |object, i| + case object + when Journey::Format + @children << i + when Parameter + @parameters << i + end + end + end + + def evaluate(hash) + parts = @parts.dup + + @parameters.each do |index| + param = parts[index] + value = hash[param.name] + return "" unless value + parts[index] = param.escape value + end + + @children.each { |index| parts[index] = parts[index].evaluate(hash) } + + parts.join + end + end + + module Visitors # :nodoc: + class Visitor # :nodoc: + DISPATCH_CACHE = {} + + 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 + def visit_LITERAL(n); terminal(n); end + def visit_SYMBOL(n); terminal(n); end + def visit_SLASH(n); terminal(n); end + def visit_DOT(n); terminal(n); end + + private_instance_methods(false).each do |pim| + next unless pim =~ /^visit_(.*)$/ + DISPATCH_CACHE[$1.to_sym] = pim + end + end + + class FunctionalVisitor # :nodoc: + DISPATCH_CACHE = {} + + def accept(node, seed) + visit(node, seed) + end + + def visit(node, seed) + send(DISPATCH_CACHE[node.type], node, seed) + end + + def binary(node, seed) + visit(node.right, visit(node.left, seed)) + end + def visit_CAT(n, seed); binary(n, seed); end + + def nary(node, seed) + node.children.inject(seed) { |s, c| visit(c, s) } + end + def visit_OR(n, seed); nary(n, seed); end + + def unary(node, seed) + visit(node.left, seed) + end + def visit_GROUP(n, seed); unary(n, seed); end + def visit_STAR(n, seed); unary(n, seed); end + + def terminal(node, seed); seed; end + def visit_LITERAL(n, seed); terminal(n, seed); end + def visit_SYMBOL(n, seed); terminal(n, seed); end + def visit_SLASH(n, seed); terminal(n, seed); end + def visit_DOT(n, seed); terminal(n, seed); end + + instance_methods(false).each do |pim| + next unless pim =~ /^visit_(.*)$/ + DISPATCH_CACHE[$1.to_sym] = pim + end + end + + class FormatBuilder < Visitor # :nodoc: + def accept(node); Journey::Format.new(super); end + def terminal(node); [node.left]; end + + def binary(node) + visit(node.left) + visit(node.right) + end + + def visit_GROUP(n); [Journey::Format.new(unary(n))]; end + + def visit_STAR(n) + [Journey::Format.required_path(n.left.to_sym)] + end + + def visit_SYMBOL(n) + symbol = n.to_sym + if symbol == :controller + [Journey::Format.required_path(symbol)] + else + [Journey::Format.required_segment(symbol)] + end + end + end + + # Loop through the requirements AST. + class Each < FunctionalVisitor # :nodoc: + def visit(node, block) + block.call(node) + super + end + + INSTANCE = new + end + + class String < FunctionalVisitor # :nodoc: + private + + def binary(node, seed) + visit(node.right, visit(node.left, seed)) + end + + def nary(node, seed) + last_child = node.children.last + node.children.inject(seed) { |s, c| + string = visit(c, s) + string << "|" unless last_child == c + string + } + end + + def terminal(node, seed) + seed + node.left + end + + def visit_GROUP(node, seed) + visit(node.left, seed.dup << "(") << ")" + end + + INSTANCE = new + end + + class Dot < FunctionalVisitor # :nodoc: + def initialize + @nodes = [] + @edges = [] + end + + def accept(node, seed = [[], []]) + super + nodes, edges = seed + <<-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, seed) + seed.last.concat node.children.map { |c| + "#{node.object_id} -> #{c.object_id};" + } + super + end + + def nary(node, seed) + seed.last.concat node.children.map { |c| + "#{node.object_id} -> #{c.object_id};" + } + super + end + + def unary(node, seed) + seed.last << "#{node.object_id} -> #{node.left.object_id};" + super + end + + def visit_GROUP(node, seed) + seed.first << "#{node.object_id} [label=\"()\"];" + super + end + + def visit_CAT(node, seed) + seed.first << "#{node.object_id} [label=\"○\"];" + super + end + + def visit_STAR(node, seed) + seed.first << "#{node.object_id} [label=\"*\"];" + super + end + + def visit_OR(node, seed) + seed.first << "#{node.object_id} [label=\"|\"];" + super + end + + def terminal(node, seed) + value = node.left + + seed.first << "#{node.object_id} [label=\"#{value}\"];" + seed + end + INSTANCE = new + end + end + end + # :startdoc: +end |