1 files changed, 49 insertions, 0 deletions
diff --git a/actionpack/lib/action_dispatch/journey/parser.y b/actionpack/lib/action_dispatch/journey/parser.y
new file mode 100644
index 0000000000..d3f7c4d765
--- /dev/null
+++ b/actionpack/lib/action_dispatch/journey/parser.y
@@ -0,0 +1,49 @@
+class ActionDispatch::Journey::Parser
+  options no_result_var
+token SLASH LITERAL SYMBOL LPAREN RPAREN DOT STAR OR
+
+rule
+  expressions
+    : expression expressions  { Cat.new(val.first, val.last) }
+    | expression              { val.first }
+    | or
+    ;
+  expression
+    : terminal
+    | group
+    | star
+    ;
+  group
+    : LPAREN expressions RPAREN { Group.new(val[1]) }
+    ;
+  or
+    : expression OR expression { Or.new([val.first, val.last]) }
+    | expression OR or { Or.new([val.first, val.last]) }
+    ;
+  star
+    : STAR       { Star.new(Symbol.new(val.last)) }
+    ;
+  terminal
+    : symbol
+    | literal
+    | slash
+    | dot
+    ;
+  slash
+    : SLASH              { Slash.new('/') }
+    ;
+  symbol
+    : SYMBOL             { Symbol.new(val.first) }
+    ;
+  literal
+    : LITERAL            { Literal.new(val.first) }
+    ;
+  dot
+    : DOT                { Dot.new(val.first) }
+    ;
+
+end
+
+---- header
+
+require 'action_dispatch/journey/parser_extras'