Refactor RFC3986 regexps to make more readable

Author: nobu

lib/uri/rfc3986_parser.rb

@@ -1,9 +1,69 @@
-# frozen_string_literal: false
+# frozen_string_literal: true
 module URI
   class RFC3986_Parser # :nodoc:
     # URI defined in RFC3986
-    RFC3986_URI = /\A(?<URI>(?<scheme>[A-Za-z][+\-.0-9A-Za-z]*+):(?<hier-part>\/\/(?<authority>(?:(?<userinfo>(?:%\h\h|[!$&-.0-;=A-Z_a-z~])*+)@)?(?<host>(?<IP-literal>\[(?:(?<IPv6address>(?:\h{1,4}:){6}(?<ls32>\h{1,4}:\h{1,4}|(?<IPv4address>(?<dec-octet>[1-9]\d|1\d{2}|2[0-4]\d|25[0-5]|\d)\.\g<dec-octet>\.\g<dec-octet>\.\g<dec-octet>))|::(?:\h{1,4}:){5}\g<ls32>|\h{1,4}?::(?:\h{1,4}:){4}\g<ls32>|(?:(?:\h{1,4}:)?\h{1,4})?::(?:\h{1,4}:){3}\g<ls32>|(?:(?:\h{1,4}:){,2}\h{1,4})?::(?:\h{1,4}:){2}\g<ls32>|(?:(?:\h{1,4}:){,3}\h{1,4})?::\h{1,4}:\g<ls32>|(?:(?:\h{1,4}:){,4}\h{1,4})?::\g<ls32>|(?:(?:\h{1,4}:){,5}\h{1,4})?::\h{1,4}|(?:(?:\h{1,4}:){,6}\h{1,4})?::)|(?<IPvFuture>v\h++\.[!$&-.0-;=A-Z_a-z~]++))\])|\g<IPv4address>|(?<reg-name>(?:%\h\h|[!$&-.0-9;=A-Z_a-z~])*+))(?::(?<port>\d*+))?)(?<path-abempty>(?:\/(?<segment>(?:%\h\h|[!$&-.0-;=@-Z_a-z~])*+))*+)|(?<path-absolute>\/(?:(?<segment-nz>(?:%\h\h|[!$&-.0-;=@-Z_a-z~])++)(?:\/\g<segment>)*+)?)|(?<path-rootless>\g<segment-nz>(?:\/\g<segment>)*+)|(?<path-empty>))(?:\?(?<query>[^#]*+))?(?:\#(?<fragment>(?:%\h\h|[!$&-.0-;=@-Z_a-z~\/?])*+))?)\z/
-    RFC3986_relative_ref = /\A(?<relative-ref>(?<relative-part>\/\/(?<authority>(?:(?<userinfo>(?:%\h\h|[!$&-.0-;=A-Z_a-z~])*+)@)?(?<host>(?<IP-literal>\[(?:(?<IPv6address>(?:\h{1,4}:){6}(?<ls32>\h{1,4}:\h{1,4}|(?<IPv4address>(?<dec-octet>[1-9]\d|1\d{2}|2[0-4]\d|25[0-5]|\d)\.\g<dec-octet>\.\g<dec-octet>\.\g<dec-octet>))|::(?:\h{1,4}:){5}\g<ls32>|\h{1,4}?::(?:\h{1,4}:){4}\g<ls32>|(?:(?:\h{1,4}:){,1}\h{1,4})?::(?:\h{1,4}:){3}\g<ls32>|(?:(?:\h{1,4}:){,2}\h{1,4})?::(?:\h{1,4}:){2}\g<ls32>|(?:(?:\h{1,4}:){,3}\h{1,4})?::\h{1,4}:\g<ls32>|(?:(?:\h{1,4}:){,4}\h{1,4})?::\g<ls32>|(?:(?:\h{1,4}:){,5}\h{1,4})?::\h{1,4}|(?:(?:\h{1,4}:){,6}\h{1,4})?::)|(?<IPvFuture>v\h++\.[!$&-.0-;=A-Z_a-z~]++))\])|\g<IPv4address>|(?<reg-name>(?:%\h\h|[!$&-.0-9;=A-Z_a-z~])++))?(?::(?<port>\d*+))?)(?<path-abempty>(?:\/(?<segment>(?:%\h\h|[!$&-.0-;=@-Z_a-z~])*+))*+)|(?<path-absolute>\/(?:(?<segment-nz>(?:%\h\h|[!$&-.0-;=@-Z_a-z~])++)(?:\/\g<segment>)*+)?)|(?<path-noscheme>(?<segment-nz-nc>(?:%\h\h|[!$&-.0-9;=@-Z_a-z~])++)(?:\/\g<segment>)*+)|(?<path-empty>))(?:\?(?<query>[^#]*+))?(?:\#(?<fragment>(?:%\h\h|[!$&-.0-;=@-Z_a-z~\/?])*+))?)\z/
+    HOST = %r[
+      (?<IP-literal>\[(?:
+          (?<IPv6address>
+            (?:\h{1,4}:){6}
+            (?<ls32>\h{1,4}:\h{1,4}
+            | (?<IPv4address>(?<dec-octet>[1-9]\d|1\d{2}|2[0-4]\d|25[0-5]|\d)
+                \.\g<dec-octet>\.\g<dec-octet>\.\g<dec-octet>)
+            )
+          | ::(?:\h{1,4}:){5}\g<ls32>
+          | \h{1,4}?::(?:\h{1,4}:){4}\g<ls32>
+          | (?:(?:\h{1,4}:)?\h{1,4})?::(?:\h{1,4}:){3}\g<ls32>
+          | (?:(?:\h{1,4}:){,2}\h{1,4})?::(?:\h{1,4}:){2}\g<ls32>
+          | (?:(?:\h{1,4}:){,3}\h{1,4})?::\h{1,4}:\g<ls32>
+          | (?:(?:\h{1,4}:){,4}\h{1,4})?::\g<ls32>
+          | (?:(?:\h{1,4}:){,5}\h{1,4})?::\h{1,4}
+          | (?:(?:\h{1,4}:){,6}\h{1,4})?::
+          )
+        | (?<IPvFuture>v\h++\.[!$&-.0-9:;=A-Z_a-z~]++)
+        )\])
+    | \g<IPv4address>
+    | (?<reg-name>(?:%\h\h|[!$&-.0-9;=A-Z_a-z~])*+)
+    ]x
+
+    USERINFO = /(?:%\h\h|[!$&-.0-9:;=A-Z_a-z~])*+/
+    AUTHORITY = %r[
+      (?:(?<userinfo>#{USERINFO.source})@)?
+      (?<host>#{HOST.source.delete(" \n")})
+      (?::(?<port>\d*+))?
+    ]x
+
+    SCHEME = %r[[A-Za-z][+\-.0-9A-Za-z]*+].source
+    SEG = %r[(?:%\h\h|[!$&-.0-9:;=@A-Z_a-z~/])].source
+    FRAGMENT = %r[(?:%\h\h|[!$&-.0-9:;=@A-Z_a-z~/?])*+].source
+
+    RFC3986_URI = %r[\A
+    (?<seg>#{SEG}){0}
+    (?<URI>
+      (?<scheme>#{SCHEME}):
+      (?<hier-part>//
+        (?<authority>#{AUTHORITY})
+        (?<path-abempty>(?:/\g<seg>*+)?)
+      | (?<path-absolute>/\g<seg>*+)
+      | (?<path-rootless>(?!=/)\g<seg>++)
+      | (?<path-empty>)
+      )
+      (?:\?(?<query>[^\#]*+))?
+      (?:\#(?<fragment>#{FRAGMENT}))?
+    )\z]x
+
+    RFC3986_relative_ref = %r[\A
+    (?<seg>#{SEG}){0}
+    (?<relative-ref>
+      (?<relative-part>//
+        (?<authority>#{AUTHORITY})
+        (?<path-abempty>(?:/\g<seg>*+)?)
+      | (?<path-absolute>/\g<seg>*+)
+      | (?<path-noscheme>(?!=[:/])\g<seg>++)
+      | (?<path-empty>)
+      )
+      (?:\?(?<query>[^#]*+))?
+      (?:\#(?<fragment>#{FRAGMENT}))?
+    )\z]x
     attr_reader :regexp
 
     def initialize
@@ -92,14 +152,14 @@ def inspect
 
     def default_regexp # :nodoc:
       {
-        SCHEME: /\A[A-Za-z][A-Za-z0-9+\-.]*\z/,
-        USERINFO: /\A(?:%\h\h|[!$&-.0-;=A-Z_a-z~])*\z/,
-        HOST: /\A(?:(?<IP-literal>\[(?:(?<IPv6address>(?:\h{1,4}:){6}(?<ls32>\h{1,4}:\h{1,4}|(?<IPv4address>(?<dec-octet>[1-9]\d|1\d{2}|2[0-4]\d|25[0-5]|\d)\.\g<dec-octet>\.\g<dec-octet>\.\g<dec-octet>))|::(?:\h{1,4}:){5}\g<ls32>|\h{,4}::(?:\h{1,4}:){4}\g<ls32>|(?:(?:\h{1,4}:)?\h{1,4})?::(?:\h{1,4}:){3}\g<ls32>|(?:(?:\h{1,4}:){,2}\h{1,4})?::(?:\h{1,4}:){2}\g<ls32>|(?:(?:\h{1,4}:){,3}\h{1,4})?::\h{1,4}:\g<ls32>|(?:(?:\h{1,4}:){,4}\h{1,4})?::\g<ls32>|(?:(?:\h{1,4}:){,5}\h{1,4})?::\h{1,4}|(?:(?:\h{1,4}:){,6}\h{1,4})?::)|(?<IPvFuture>v\h+\.[!$&-.0-;=A-Z_a-z~]+))\])|\g<IPv4address>|(?<reg-name>(?:%\h\h|[!$&-.0-9;=A-Z_a-z~])*))\z/,
-        ABS_PATH: /\A\/(?:%\h\h|[!$&-.0-;=@-Z_a-z~])*(?:\/(?:%\h\h|[!$&-.0-;=@-Z_a-z~])*)*\z/,
-        REL_PATH: /\A(?:%\h\h|[!$&-.0-;=@-Z_a-z~])+(?:\/(?:%\h\h|[!$&-.0-;=@-Z_a-z~])*)*\z/,
-        QUERY: /\A(?:%\h\h|[!$&-.0-;=@-Z_a-z~\/?])*\z/,
-        FRAGMENT: /\A(?:%\h\h|[!$&-.0-;=@-Z_a-z~\/?])*\z/,
-        OPAQUE: /\A(?:[^\/].*)?\z/,
+        SCHEME: %r[\A#{SCHEME}\z]o,
+        USERINFO: %r[\A#{USERINFO}\z]o,
+        HOST: %r[\A#{HOST}\z]o,
+        ABS_PATH: %r[\A/#{SEG}*+\z]o,
+        REL_PATH: %r[\A(?!=/)#{SEG}++\z]o,
+        QUERY: %r[\A(?:%\h\h|[!$&-.0-9:;=@A-Z_a-z~/?])*+\z],
+        FRAGMENT: %r[\A#{FRAGMENT}\z]o,
+        OPAQUE: %r[\A(?:[^/].*)?\z],
         PORT: /\A[\x09\x0a\x0c\x0d ]*\d*[\x09\x0a\x0c\x0d ]*\z/,
       }
     end