[io grant] Make IO::Spec::Cygwin.is-absolute 21x faster

rakudo · May 14, 2017 · 48cf0e6 · 48cf0e6
1 parent 7c8f8d3
commit 48cf0e6
Showing 1 changed file with 9 additions and 2 deletions.
diff --git a/src/core/IO/Spec/Cygwin.pm b/src/core/IO/Spec/Cygwin.pm
@@ -19,8 +19,15 @@ my class IO::Spec::Cygwin is IO::Spec::Unix {
         $result.subst(/ <[\\\/]> ** 2..*/, '/');
     }
 
-    method is-absolute ($file) {
-        so $file ~~ / ^ [<[A..Z a..z]> ':']?  <[\\/]>/; # C:/test
+    method is-absolute ($path) {
+        nqp::p6bool(
+          nqp::iseq_i(($_ := nqp::ord($path)), 92) # /^ ｢\｣ /
+          || nqp::iseq_i($_, 47)                   # /^ ｢/｣ /
+          || (nqp::eqat($path, ':', 1) # /^ <[A..Z a..z]> ':' [ ｢\｣ | ｢/｣ ] /
+              && ( (nqp::isge_i($_, 65) && nqp::isle_i($_, 90)) # drive letter
+                || (nqp::isge_i($_, 97) && nqp::isle_i($_, 122)))
+              && ( nqp::iseq_i(($_ := nqp::ordat($path, 2)), 92) # slash
+                || nqp::iseq_i($_, 47))))
     }
 
     method tmpdir {