Files
c3c/lib/std/sort/binarysearch.c3
Zack Puhl 12975d07ac [stdlib] Reduce inline code volume from sorting macros (#2831)
* reduce codegen in sorting macros

* remove testing file...

* Fix and some renaming, removing some sub-modules that should not be in use.

---------

Co-authored-by: Christoffer Lerno <christoffer@aegik.com>
2026-01-31 20:19:57 +01:00

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module std::sort;
<*
Perform a binary search over the sorted array and return the index
in [0, array.len) where x would be inserted or cmp(i) is true and cmp(j) is true for j in [i, array.len).
@require @list_is_by_ref(list) : "Expected a list passed by reference or a slice"
@require @is_sortable(list) : "The list must be sortable"
@require @is_valid_cmp_fn(#cmp: ...cmp, #list: list, #context: ...context) : "Expected a comparison function which compares values"
@require @is_valid_context(...cmp, ...context) : "Expected a valid context"
*>
macro usz binarysearch(list, element, cmp = ..., context = ...) @builtin
{
var used_cmp = $defined(cmp) ??? cmp : (TypeNotSet)null;
var used_ctx = $defined(context) ??? context : (TypeNotSet)null;
return _binarysearch{$typeof(list), $typeof(element), $typeof(used_cmp), $typeof(used_ctx)}(list, element, used_cmp, used_ctx);
}
fn usz _binarysearch(ListType list, ElementType element, CmpFnType cmp, ContextType context) <ListType, ElementType, CmpFnType, ContextType> @noinline @local
{
usz i;
var $no_cmp = $typeof(cmp) == TypeNotSet;
var $has_context = $typeof(context) != TypeNotSet;
$if $kindof(list) == SLICE:
usz len = lengthof(list);
for (usz j = len; i < j;)
{
usz half = i + (j - i) / 2;
$if $no_cmp:
switch
{
case greater(list[half], element): j = half;
case less(list[half], element): i = half + 1;
default: return half;
}
$else
$switch:
$case $defined(cmp(list[0], list[0], context)):
int res = cmp(list[half], element, context);
$case $defined(cmp(list[0], list[0])):
assert(!$has_context);
int res = cmp(list[half], element);
$case $defined(cmp(&list[0], &list[0], context)):
int res = cmp(&list[half], &element, context);
$case $defined(cmp(&list[0], &list[0])):
assert(!$has_context);
int res = cmp(&list[half], &element);
$default:
assert(false, "Invalid comparison function");
$endswitch
switch
{
case res > 0: j = half;
case res < 0: i = half + 1;
default: return half;
}
$endif
}
$else
usz len = lengthof(*list);
for (usz j = len; i < j;)
{
usz half = i + (j - i) / 2;
$if $no_cmp:
switch
{
case greater((*list)[half], element): j = half;
case less((*list)[half], element): i = half + 1;
default: return half;
}
$else
$switch:
$case $defined(cmp((*list)[0], (*list)[0], context)):
int res = cmp(list[half], element, context);
$case $defined(cmp((*list)[0], (*list)[0])):
assert(!$has_context);
int res = cmp((*list)[half], element);
$case $defined(cmp(&(*list)[0], &(*list)[0], context)):
int res = cmp(&(*list)[half], &element, context);
$case $defined(cmp(&(*list)[0], &(*list)[0])):
assert(!$has_context);
int res = cmp(&(*list)[half], &element);
$default:
assert(false, "Invalid comparison function");
$endswitch
switch
{
case res > 0: j = half;
case res < 0: i = half + 1;
default: return half;
}
$endif
}
$endif
return i;
}