A list value of numbers copied whole (140's LIST_VALUE review, no new opcode, no change to what a module means): nest() made every list value item by item into a new tree (64 ns an item, 250 ns a copy fixed); an event's list in FLAT arrays, not keyed, its cells numbers, bools and integers, is now copied column by column (pure_list_copied: 600 items 38,268 to 985 ns, 60 items 3,926 to 324); UAX #14's nine lists a line 6,917 to 6,445 ns a code point (-6.8%, the same instructions); JSON tree's, HTTP's and inflate's (trees: texts or lists in their records, or few) as they were; copied_lists in test-module (random lists against item by item, then each changed apart; trees, keys and texts not copied so)

1 files changed, 4 insertions, 3 deletions

diff --git a/core/module.c b/core/module.c
index 3a6c4b5..f970daf 100644
--- a/core/module.c
+++ b/core/module.c
@@ -2668,10 +2668,11 @@ static uint64_t nest(PureApp *app, uint32_t record, const PureList *from) {
         app->nested.shared = shared;
         app->nested.capacity = capacity;
     }
-    PureList *list = new_list(m, record, false);
-    if (!list) return 0;
+    PureList *list = from && !m->record_nested[record] ? pure_list_copied(from) : NULL; /* numbers in arrays: at once */
+    size_t at = list ? pure_list_count(from) : 0;
+    if (!list && !(list = new_list(m, record, false))) return 0;
     const PureRecord *r = &m->record[record];
-    for (size_t at = 0, count = from ? pure_list_count(from) : 0; at < count; ++at) {
+    for (size_t count = from ? pure_list_count(from) : 0; at < count; ++at) {
         PureCell cells[PURE_RECORD_FIELDS];
         for (unsigned f = 0; f < r->count; ++f) cells[f] = pure_list_get(from, at, f);
         if (pure_list_insert(list, at, cells, NULL) != PURE_OK) { pure_list_free(list); return 0; }