coq: use a Requirement

1 files changed, 22 insertions, 9 deletions

diff --git a/Library/Formula/coq.rb b/Library/Formula/coq.rb
index 78e272877..88e45c927 100644
--- a/Library/Formula/coq.rb
+++ b/Library/Formula/coq.rb
@@ -1,22 +1,36 @@
 require 'formula'
 
+class TransitionalMode < Requirement
+  def message; <<-EOS.undent
+    camlp5 must be compiled in transitional mode (instead of --strict mode):
+      brew install camlp5
+    EOS
+  end
+  def satisfied?
+    # If not installed, it will install in the correct mode.
+    return true if not which('camlp5')
+    # If installed, make sure it is transitional instead of strict.
+    `camlp5 -pmode 2>&1`.chomp == 'transitional'
+  end
+  def fatal?
+    true
+  end
+end
+
 class Coq < Formula
+  homepage 'http://coq.inria.fr/'
   url 'http://coq.inria.fr/distrib/V8.3pl3/files/coq-8.3pl3.tar.gz'
   version '8.3pl3'
-  head 'svn://scm.gforge.inria.fr/svn/coq/trunk'
-  homepage 'http://coq.inria.fr/'
   md5 '37e9a52110a025128667c03fed75f9c2'
+  head 'svn://scm.gforge.inria.fr/svn/coq/trunk'
 
   skip_clean :all
 
+  depends_on TransitionalMode.new
   depends_on 'objective-caml'
   depends_on 'camlp5'
 
   def install
-    unless `camlp5 -pmode 2>&1`.chomp == 'transitional'
-      onoe 'camlp5 must be compiled in transitional mode (--transitional option)'
-      exit 1
-    end
     arch = Hardware.is_64_bit? ? "x86_64" : "i386"
     camlp5_lib = Formula.factory('camlp5').lib+'ocaml/camlp5'
     system "./configure", "-prefix", prefix,
@@ -32,13 +46,12 @@ class Coq < Formula
     system "make install"
   end
 
-  def caveats
-    <<-EOS.undent
+  def caveats; <<-EOS.undent
     Coq's Emacs mode is installed into
       #{lib}/emacs/site-lisp
+
     To use the Coq Emacs mode, you need to put the following lines in
     your .emacs file:
-
       (setq auto-mode-alist (cons '("\\.v$" . coq-mode) auto-mode-alist))
       (autoload 'coq-mode "coq" "Major mode for editing Coq vernacular." t)
     EOS