From: Christophe Rhodes <csr21@cam.ac.uk>
Date: Fri, 31 Jan 2003 15:08:28 +0000 (+0000)
Subject: 0.7.12.14:
X-Git-Url: http://repo.macrolet.net/gitweb/?a=commitdiff_plain;h=4704aaa73743e936db4ffaeeb4331b33d58a1acf;p=sbcl.git

0.7.12.14:
	Type system fixes (thanks to Paul Dietz for the report)
	... make the intersection of negation types with non-hairy types
		smarter, by considering the type relationship of the
		negation (e.g. (AND BASE-CHAR (NOT BASE-CHAR)) and
		(AND FIXNUM (NOT INTEGER)) should both be canonicalized
		to NIL).
	... if either of the CAR-type or CDR-type of a CONS type is NIL,
		then the whole type must be NIL too.
	(also fixes the unparse of EXTENDED-CHAR)
---

diff --git a/src/code/late-type.lisp b/src/code/late-type.lisp
index abb2340..5d3b845 100644
--- a/src/code/late-type.lisp
+++ b/src/code/late-type.lisp
@@ -1201,12 +1201,23 @@
   (declare (ignore type1 type2))
   (values nil nil))
 
-(!define-type-method (hairy :simple-intersection2 :complex-intersection2)
+(!define-type-method (hairy :simple-intersection2) 
 		     (type1 type2)
   (if (type= type1 type2)
       type1
       nil))
 
+(!define-type-method (hairy :complex-intersection2)
+		     (type1 type2)
+  (aver (hairy-type-p type2))
+  (let ((hairy-type-spec (type-specifier type2)))
+    (if (and (consp hairy-type-spec)
+	     (eq (car hairy-type-spec) 'not))
+	(if (csubtypep type1 (specifier-type (cadr hairy-type-spec)))
+	    *empty-type*
+	    nil)
+	nil)))
+	
 (!define-type-method (hairy :simple-=) (type1 type2)
   (if (equal (hairy-type-specifier type1)
 	     (hairy-type-specifier type2))
@@ -2414,8 +2425,12 @@
 (!define-type-class cons)
 
 (!def-type-translator cons (&optional (car-type-spec '*) (cdr-type-spec '*))
-  (make-cons-type (specifier-type car-type-spec)
-		  (specifier-type cdr-type-spec)))
+  (let ((car-type (specifier-type car-type-spec))
+	(cdr-type (specifier-type cdr-type-spec)))
+    (if (or (eq car-type *empty-type*)
+	    (eq cdr-type *empty-type*))
+	*empty-type*
+	(make-cons-type car-type cdr-type))))
  
 (!define-type-method (cons :unparse) (type)
   (let ((car-eltype (type-specifier (cons-type-car-type type)))
diff --git a/tests/type.pure.lisp b/tests/type.pure.lisp
index a770835..8026733 100644
--- a/tests/type.pure.lisp
+++ b/tests/type.pure.lisp
@@ -33,7 +33,8 @@
 ;;; SINGLE-FLOAT DOUBLE-FLOAT RATIONAL)".  We ideally want all of the
 ;;; defined-by-ANSI types to unparse as themselves or at least
 ;;; something similar (e.g. CHARACTER can unparse to BASE-CHAR, since
-;;; the types are equivalent in current SBCL).
+;;; the types are equivalent in current SBCL, and EXTENDED-CHAR can
+;;; unparse to NIL, since there are no EXTENDED-CHARs currently).
 (let ((standard-types '(;; from table 4-2 in section 4.2.3 in the
 			;; CLHS.
 			arithmetic-error
@@ -117,17 +118,7 @@
 			error
 			readtable
 			two-way-stream
-			;; This one's hard: (AND BASE-CHAR (NOT BASE-CHAR))
-			;;
-			;; This is because it looks like
-			;;   (AND CHARACTER (NOT BASE-CHAR))
-			;; but CHARACTER is equivalent to
-			;; BASE-CHAR. So if we fix intersection of
-			;; obviously disjoint types and then do (the
-			;; extended-char foo), we'll get back FOO is
-			;; not a NIL. -- CSR, 2002-09-16.
-			;;
-			;; extended-char
+			extended-char
 			real
 			type-error                 
 			file-error
diff --git a/version.lisp-expr b/version.lisp-expr
index 145255d..efe04d3 100644
--- a/version.lisp-expr
+++ b/version.lisp-expr
@@ -18,4 +18,4 @@
 ;;; versions, especially for internal versions off the main CVS
 ;;; branch, it gets hairier, e.g. "0.pre7.14.flaky4.13".)
 
-"0.7.12.13"
+"0.7.12.14"