Merge pull request rails#52610 from Shopify/no_more_racc

Remove racc

Author: gmcgibbon

Gemfile

@@ -152,9 +152,6 @@ end
 platforms :ruby, :windows do
   gem "nokogiri", ">= 1.8.1", "!= 1.11.0"
 
-  # Needed for compiling the ActionDispatch::Journey parser.
-  gem "racc", ">=1.4.6", require: false
-
   # Active Record.
   gem "sqlite3", ">= 1.6.6"
 

Gemfile.lock

@@ -51,7 +51,6 @@ PATH
       actionview (= 8.0.0.alpha)
       activesupport (= 8.0.0.alpha)
       nokogiri (>= 1.8.5)
-      racc
       rack (>= 2.2.4)
       rack-session (>= 1.0.1)
       rack-test (>= 0.6.3)
@@ -666,7 +665,6 @@ DEPENDENCIES
   propshaft (>= 0.1.7)
   puma (>= 5.0.3)
   queue_classic (>= 4.0.0)
-  racc (>= 1.4.6)
   rack (~> 3.0)
   rack-cache (~> 1.2)
   rails!

actionpack/CHANGELOG.md

@@ -1,3 +1,7 @@
+*   Remove `racc` dependency by manually writing `ActionDispatch::Journey::Scanner`.
+
+    *Gannon McGibbon*
+
 *   Speed up `ActionDispatch::Routing::Mapper::Scope#[]` by merging frame hashes.
 
     *Gannon McGibbon*

actionpack/actionpack.gemspec

@@ -36,7 +36,6 @@ Gem::Specification.new do |s|
   s.add_dependency "activesupport", version
 
   s.add_dependency "nokogiri", ">= 1.8.5"
-  s.add_dependency "racc"
   s.add_dependency "rack",      ">= 2.2.4"
   s.add_dependency "rack-session", ">= 1.0.1"
   s.add_dependency "rack-test", ">= 0.6.3"

actionpack/lib/action_dispatch/journey/parser.rb

@@ -1,200 +1,103 @@
-#
-# DO NOT MODIFY!!!!
-# This file is automatically generated by Racc 1.4.16 from
-# Racc grammar file "".
 
-# :markup: markdown
+require "action_dispatch/journey/scanner"
+require "action_dispatch/journey/nodes/node"
 
-require 'racc/parser.rb'
-
-# :stopdoc:
-
-require "action_dispatch/journey/parser_extras"
 module ActionDispatch
-  module Journey
-    class Parser < Racc::Parser
-##### State transition tables begin ###
-
-racc_action_table = [
-    13,    15,    14,     7,    19,    16,     8,    19,    13,    15,
-    14,     7,    17,    16,     8,    13,    15,    14,     7,    21,
-    16,     8,    13,    15,    14,     7,    24,    16,     8 ]
-
-racc_action_check = [
-     2,     2,     2,     2,    22,     2,     2,     2,    19,    19,
-    19,    19,     1,    19,    19,     7,     7,     7,     7,    17,
-     7,     7,     0,     0,     0,     0,    20,     0,     0 ]
-
-racc_action_pointer = [
-    20,    12,    -2,   nil,   nil,   nil,   nil,    13,   nil,   nil,
-   nil,   nil,   nil,   nil,   nil,   nil,   nil,    19,   nil,     6,
-    20,   nil,    -5,   nil,   nil ]
-
-racc_action_default = [
-   -19,   -19,    -2,    -3,    -4,    -5,    -6,   -19,   -10,   -11,
-   -12,   -13,   -14,   -15,   -16,   -17,   -18,   -19,    -1,   -19,
-   -19,    25,    -8,    -9,    -7 ]
-
-racc_goto_table = [
-     1,    22,    18,    23,   nil,   nil,   nil,    20 ]
-
-racc_goto_check = [
-     1,     2,     1,     3,   nil,   nil,   nil,     1 ]
-
-racc_goto_pointer = [
-   nil,     0,   -18,   -16,   nil,   nil,   nil,   nil,   nil,   nil,
-   nil ]
-
-racc_goto_default = [
-   nil,   nil,     2,     3,     4,     5,     6,     9,    10,    11,
-    12 ]
-
-racc_reduce_table = [
-  0, 0, :racc_error,
-  2, 11, :_reduce_1,
-  1, 11, :_reduce_2,
-  1, 11, :_reduce_none,
-  1, 12, :_reduce_none,
-  1, 12, :_reduce_none,
-  1, 12, :_reduce_none,
-  3, 15, :_reduce_7,
-  3, 13, :_reduce_8,
-  3, 13, :_reduce_9,
-  1, 16, :_reduce_10,
-  1, 14, :_reduce_none,
-  1, 14, :_reduce_none,
-  1, 14, :_reduce_none,
-  1, 14, :_reduce_none,
-  1, 19, :_reduce_15,
-  1, 17, :_reduce_16,
-  1, 18, :_reduce_17,
-  1, 20, :_reduce_18 ]
-
-racc_reduce_n = 19
-
-racc_shift_n = 25
-
-racc_token_table = {
-  false => 0,
-  :error => 1,
-  :SLASH => 2,
-  :LITERAL => 3,
-  :SYMBOL => 4,
-  :LPAREN => 5,
-  :RPAREN => 6,
-  :DOT => 7,
-  :STAR => 8,
-  :OR => 9 }
-
-racc_nt_base = 10
-
-racc_use_result_var = false
-
-Racc_arg = [
-  racc_action_table,
-  racc_action_check,
-  racc_action_default,
-  racc_action_pointer,
-  racc_goto_table,
-  racc_goto_check,
-  racc_goto_default,
-  racc_goto_pointer,
-  racc_nt_base,
-  racc_reduce_table,
-  racc_token_table,
-  racc_shift_n,
-  racc_reduce_n,
-  racc_use_result_var ]
-
-Racc_token_to_s_table = [
-  "$end",
-  "error",
-  "SLASH",
-  "LITERAL",
-  "SYMBOL",
-  "LPAREN",
-  "RPAREN",
-  "DOT",
-  "STAR",
-  "OR",
-  "$start",
-  "expressions",
-  "expression",
-  "or",
-  "terminal",
-  "group",
-  "star",
-  "symbol",
-  "literal",
-  "slash",
-  "dot" ]
-
-Racc_debug_parser = false
-
-##### State transition tables end #####
-
-# reduce 0 omitted
-
-def _reduce_1(val, _values)
- Cat.new(val.first, val.last)
-end
-
-def _reduce_2(val, _values)
- val.first
-end
-
-# reduce 3 omitted
-
-# reduce 4 omitted
-
-# reduce 5 omitted
-
-# reduce 6 omitted
-
-def _reduce_7(val, _values)
- Group.new(val[1])
-end
-
-def _reduce_8(val, _values)
- Or.new([val.first, val.last])
-end
-
-def _reduce_9(val, _values)
- Or.new([val.first, val.last])
-end
-
-def _reduce_10(val, _values)
- Star.new(Symbol.new(val.last, Symbol::GREEDY_EXP))
+  module Journey # :nodoc:
+    class Parser # :nodoc:
+      include Journey::Nodes
+
+      def self.parse(string)
+        new.parse string
+      end
+
+      def initialize
+        @scanner = Scanner.new
+        @next_token = nil
+      end
+
+      def parse(string)
+        @scanner.scan_setup(string)
+        advance_token
+        do_parse
+      end
+
+      private
+
+      def advance_token
+        @next_token = @scanner.next_token
+      end
+
+      def do_parse
+        parse_expressions
+      end
+
+      def parse_expressions
+        node = parse_expression
+
+        while @next_token
+          case @next_token.first
+          when :RPAREN
+            break
+          when :OR
+            node = parse_or(node)
+          else
+            node = Cat.new(node, parse_expressions)
+          end
+        end
+
+        node
+      end
+
+      def parse_or(lhs)
+        advance_token
+        node = parse_expression
+        Or.new([lhs, node])
+      end
+
+      def parse_expression
+        if @next_token.first == :STAR
+          parse_star
+        elsif @next_token.first == :LPAREN
+          parse_group
+        else
+          parse_terminal
+        end
+      end
+
+      def parse_star
+        node = Star.new(Symbol.new(@next_token.last, Symbol::GREEDY_EXP))
+        advance_token
+        node
+      end
+
+      def parse_group
+        advance_token
+        node = parse_expressions
+        if @next_token.first == :RPAREN
+          node = Group.new(node)
+          advance_token
+          node
+        else
+          raise "error"
+        end
+      end
+
+      def parse_terminal
+        node = case @next_token.first
+        when :SYMBOL
+          Symbol.new(@next_token.last)
+        when :LITERAL
+          Literal.new(@next_token.last)
+        when :SLASH
+          Slash.new(@next_token.last)
+        when :DOT
+          Dot.new(@next_token.last)
+        end
+
+        advance_token
+        node
+      end
+    end
+  end
 end
-
-# reduce 11 omitted
-
-# reduce 12 omitted
-
-# reduce 13 omitted
-
-# reduce 14 omitted
-
-def _reduce_15(val, _values)
- Slash.new(val.first)
-end
-
-def _reduce_16(val, _values)
- Symbol.new(val.first)
-end
-
-def _reduce_17(val, _values)
- Literal.new(val.first)
-end
-
-def _reduce_18(val, _values)
- Dot.new(val.first)
-end
-
-def _reduce_none(val, _values)
-  val[0]
-end
-
-    end   # class Parser
-  end   # module Journey
-end   # module ActionDispatch