1 files changed, 43 insertions, 0 deletions
diff --git a/tool/lrama/lib/lrama/grammar/parameterizing_rules/builder.rb b/tool/lrama/lib/lrama/grammar/parameterizing_rules/builder.rb
new file mode 100644
index 0000000000..28c9ad427d
--- /dev/null
+++ b/tool/lrama/lib/lrama/grammar/parameterizing_rules/builder.rb
@@ -0,0 +1,43 @@
+require 'lrama/grammar/parameterizing_rules/builder/base'
+require 'lrama/grammar/parameterizing_rules/builder/list'
+require 'lrama/grammar/parameterizing_rules/builder/nonempty_list'
+require 'lrama/grammar/parameterizing_rules/builder/option'
+require 'lrama/grammar/parameterizing_rules/builder/separated_nonempty_list'
+require 'lrama/grammar/parameterizing_rules/builder/separated_list'
+
+module Lrama
+  class Grammar
+    class ParameterizingRules
+      class Builder
+        RULES = {
+          option: Lrama::Grammar::ParameterizingRules::Builder::Option,
+          "?": Lrama::Grammar::ParameterizingRules::Builder::Option,
+          nonempty_list: Lrama::Grammar::ParameterizingRules::Builder::NonemptyList,
+          "+": Lrama::Grammar::ParameterizingRules::Builder::NonemptyList,
+          list: Lrama::Grammar::ParameterizingRules::Builder::List,
+          "*": Lrama::Grammar::ParameterizingRules::Builder::List,
+          separated_nonempty_list: Lrama::Grammar::ParameterizingRules::Builder::SeparatedNonemptyList,
+          separated_list: Lrama::Grammar::ParameterizingRules::Builder::SeparatedList,
+        }
+
+        def initialize(token, rule_counter, lhs, user_code, precedence_sym, line)
+          @token = token
+          @key = token.s_value.to_sym
+          @rule_counter = rule_counter
+          @lhs = lhs
+          @user_code = user_code
+          @precedence_sym = precedence_sym
+          @line = line
+        end
+
+        def build
+          if RULES.key?(@key)
+            RULES[@key].new(@token, @rule_counter, @lhs, @user_code, @precedence_sym, @line).build
+          else
+            raise "Parameterizing rule does not exist. `#{@key}`"
+          end
+        end
+      end
+    end
+  end
+end