Ensure all lists of lists are marked as rectangular tables when appro…

…priate

src/plist.c

@@ -287,20 +287,22 @@ static Int KTNumPlist(Obj list, Obj * famfirst)
  }
  isHom = 1;
  areMut = IS_MUTABLE_OBJ(elm);
- if ( ktnumFirst >= T_PLIST_HOM ||
- ( ktnumFirst == 0 && IS_HOMOG_LIST( elm) )) {
 
- // entry is a homogeneous list, so this might be a table
- isTable = 1;
-
- // also check for rectangularity, unless this would be expensive
- if (IS_PLIST(elm))
- {
+ // if entry is a homogeneous list this might be a table or list
+ if (ktnumFirst >= T_PLIST_HOM) {
+ isTable = 1;
+ isRect = 1;
+ len = LEN_PLIST(elm);
+ }
+ else if (ktnumFirst == 0 && IS_HOMOG_LIST(elm)) {
+ isTable = 1;
+ // Only handle small lists as rectangular
+ if(IS_SMALL_LIST(elm)) {
  isRect = 1;
- len = LEN_PLIST(elm);
+ len = LEN_LIST(elm);
  }
-
  }
+
  if (!testing) CLEAR_OBJ_FLAG(list, OBJ_FLAG_TESTING);
  }
 
@@ -342,16 +344,21 @@ static Int KTNumPlist(Obj list, Obj * famfirst)
  isRect = 0;
  }
  if ( isTable ) {
- // IS_PLIST first, as it is much cheaper
- if (!(IS_PLIST(elm) || IS_LIST(elm))) {
- isTable = 0;
- isRect = 0;
+ // Check IS_PLIST first, as it is much cheaper
+ if (IS_PLIST(elm)) {
+ if (isRect && LEN_PLIST(elm) != len) {
+ isRect = 0;
+ }
  }
- if ( isRect ) {
- if ( !(IS_PLIST(elm) && LEN_PLIST(elm) == len) ) {
+ else if (IS_SMALL_LIST(elm)) {
+ if (isRect && LEN_LIST(elm) != len) {
  isRect = 0;
  }
  }
+ else {
+ isTable = 0;
+ isRect = 0;
+ }
  }
  }
  areMut = (areMut || IS_MUTABLE_OBJ(elm));

tst/testinstall/table.tst

@@ -0,0 +1,31 @@
+#@local u,v, check
+gap> START_TEST("table.tst");
+gap> check := {m} -> [IsTable(m), IsRectangularTable(m), HasIsRectangularTable(m) ];
+function( m ) ... end
+gap> check( [ ]);
+[ false, false, false ]
+gap> check( [ [] ]);
+[ false, false, false ]
+gap> check( [ [], [] ]);
+[ false, false, false ]
+gap> check([ [1,2], [3,4] ]);
+[ true, true, true ]
+gap> check( [ [1,2], [3]]);
+[ true, false, false ]
+gap> check( [ "ab", "cd" ]);
+[ true, true, true ]
+gap> check( [ ['a', 'b'], "cd"]);
+[ true, true, true ]
+gap> check( [ "ab", ['a', 'b']]);
+[ true, true, true ]
+gap> check( [ [1,2], "cd"]);
+[ false, false, false ]
+gap> check( [ [1,2], 3]);
+[ false, false, false ]
+gap> check(InfiniteListOfNames("a"));
+[ false, false, true ]
+gap> check([InfiniteListOfNames("a")]);
+[ true, true, true ]
+gap> check([ ["a","b"], InfiniteListOfNames("a")]);
+[ false, false, false ]
+gap> STOP_TEST( "table.tst", 1);