mirror of
https://github.com/postgres/postgres.git
synced 2026-03-17 16:12:13 -04:00
The standard way to check for list emptiness is to compare the List pointer to NIL; our list code goes out of its way to ensure that that is the only representation of an empty list. (An acceptable alternative is a plain boolean test for non-null pointer, but explicit mention of NIL is usually preferable.) Various places didn't get that memo and expressed the condition with list_length(), which might not be so bad except that there were such a variety of ways to check it exactly: equal to zero, less than or equal to zero, less than one, yadda yadda. In the name of code readability, let's standardize all those spellings as "list == NIL" or "list != NIL". (There's probably some microscopic efficiency gain too, though few of these look to be at all performance-critical.) A very small number of cases were left as-is because they seemed more consistent with other adjacent list_length tests that way. Peter Smith, with bikeshedding from a number of us Discussion: https://postgr.es/m/CAHut+PtQYe+ENX5KrONMfugf0q6NHg4hR5dAhqEXEc2eefFeig@mail.gmail.com |
||
|---|---|---|
| .. | ||
| allpaths.c | ||
| clausesel.c | ||
| costsize.c | ||
| equivclass.c | ||
| indxpath.c | ||
| joinpath.c | ||
| joinrels.c | ||
| Makefile | ||
| pathkeys.c | ||
| tidpath.c | ||