Fix negative zero

core/math/parser/parser-tests.factor

@@ -77,10 +77,6 @@ unit-test
 [ "-101.0e-2" string>number number>string ]
 unit-test
 
-[ 5.0 ]
-[ "10.0/2" string>number ]
-unit-test
-
 [ f ]
 [ "1e1/2" string>number ]
 unit-test
@@ -104,3 +100,5 @@ unit-test
 [ "1.0/0.0" ] [ 1.0 0.0 / number>string ] unit-test
 
 [ "-1.0/0.0" ] [ -1.0 0.0 / number>string ] unit-test
+
+[ "-0.0" ] [ -0.0 number>string ] unit-test

core/math/parser/parser.factor

@@ -73,13 +73,14 @@ PRIVATE>
 
 : base> ( str radix -- n/f )
     [
-        "-" ?head dup negative? set >r
-        {
-            { [ CHAR: / over member? ] [ string>ratio ] }
-            { [ CHAR: . over member? ] [ string>float ] }
-            [ string>integer ]
-        } cond
-        r> [ dup [ neg ] when ] when
+        CHAR: . over member? [
+            string>float
+        ] [
+            "-" ?head dup negative? set >r
+            CHAR: / over member?
+            [ string>ratio ] [ string>integer ] if
+            r> [ dup [ neg ] when ] when
+        ] if
     ] with-radix ;
 
 : string>number ( str -- n/f ) 10 base> ;