seq_build: seq_pend must be nondestructive for lists.

Let's have both a seq_pend and seq_nconc, where seq_nconc
can reuse the pieces of list passed to it.

* lib.h (struct seq_build_ops): New member, nconc.
(seq_build_ops_init): Add nconc parameter and initializer.
(seq_nconc): Function declared.

* lib.c (seq_build_list_pend): Switch to list_collect_append,
otherwise mappend behaves destructively.
(seq_build_list_nconc): New function.
(sb_vec_ops, sb_str_ops, sb_buf_ops, sb_struct_ops,
sb_carray_ops): Use seq_build_generic_pend for nconc
operation.
(sb_list_ops): Use new seq_build_list_nconc for nconc
operation.
(sb_finished_ops): Use null pointer for nconc operation.
(seq_nconc): New function.

0 files changed, 0 insertions, 0 deletions