pcre: support for the regexp literal syntax from the regexp vocab

basis/pcre/pcre-tests.factor

@@ -10,6 +10,7 @@ USING:
     sequences
     system
     tools.test ;
+QUALIFIED: regexp
 IN: pcre.tests
 
 CONSTANT: iso-date "(?P<year>\\d{4})-(?P<month>\\d{2})-(?P<day>\\d{2})"
@@ -117,3 +118,6 @@ os unix? [ [ 10 ] [ PCRE_CONFIG_NEWLINE config ] unit-test ] when
     "http://factorcode.org/" http-get nip
     "href=\"(?P<link>[^\"]+)\"" findall [ "link" of ] map sequence?
 ] unit-test
+
+! Test that the regexp syntax works.
+[ t ] [ "1234abcd" regexp:R[ ^\d+\w+$] matches? ] unit-test

basis/pcre/pcre.factor

@@ -10,6 +10,7 @@ USING:
     pcre.ffi pcre.info pcre.utils
     sequences sequences.generalizations
     strings ;
+QUALIFIED: regexp
 IN: pcre
 
 ERROR: malformed-regexp expr error ;
@@ -90,6 +91,9 @@ M: compiled-pcre findall
 M: string findall
     <compiled-pcre> findall ;
 
+M: regexp:regexp findall
+    raw>> findall ;
+
 : matches? ( subject obj -- ? )
     dupd findall [ nip length 1 = ] [ ?first ?first ?last = ] 2bi and ;