ANCHOR_KEEP      1504 regcomp.c        case ANCHOR_KEEP:           r = add_opcode(reg, OP_KEEP);           break;
ANCHOR_KEEP      4122 regcomp.c        ANCHOR_END_LINE | ANCHOR_BEGIN_BUF | ANCHOR_BEGIN_POSITION | ANCHOR_KEEP | \
ANCHOR_KEEP      4127 regcomp.c        ANCHOR_END_LINE | ANCHOR_BEGIN_BUF | ANCHOR_BEGIN_POSITION | ANCHOR_KEEP | \
ANCHOR_KEEP      6673 regcomp.c          case ANCHOR_KEEP:            fputs("keep",f);            break;
ANCHOR_KEEP      5988 regparse.c         *np = onig_node_new_anchor(ANCHOR_KEEP);