Return to put.c CVS log

Up to [CSRG BSD Unix] / 43BSD / contrib / icon / functions

Annotation of 43BSD/contrib/icon/functions/put.c, revision 1.1.1.1

1.1       root        1: #include "../h/rt.h"
                      2: 
                      3: /*
                      4:  * put(x,val) - put val onto end of list x.
                      5:  */
                      6: Xput(nargs, arg2, arg1, arg0)
                      7: int nargs;
                      8: struct descrip arg2, arg1, arg0;
                      9:    {
                     10:    register int i;
                     11:    register struct b_list *hp;
                     12:    register struct b_lelem *bp;
                     13:    extern struct b_lelem *alclstb();
                     14: 
                     15:    /*
                     16:     * x must be a list.
                     17:     */
                     18:    DeRef(arg1)
                     19:    DeRef(arg2)
                     20:    if (QUAL(arg1) || TYPE(arg1) != T_LIST)
                     21:       runerr(108, &arg1);
                     22: 
                     23:    /*
                     24:     * A new list element block might be needed, so ensure space for it.
                     25:     */
                     26:    hneed(sizeof(struct b_lelem)+LISTBLKSIZE*sizeof(struct descrip));
                     27: 
                     28:    /*
                     29:     * Point hp at the list header block and bp at the last list element block.
                     30:     */
                     31:    hp = (struct b_list *) BLKLOC(arg1);
                     32:    bp = (struct b_lelem *) BLKLOC(hp->listtail);
                     33: 
                     34:    /*
                     35:     * If the last list element block is full,
                     36:     *  allocate a new list element block, make it the first list
                     37:     *  element block and it make it the next block of the
                     38:     *  former last list element block.
                     39:     */
                     40:    if (bp->nused >= bp->nelem) {
                     41:       bp = alclstb(LISTBLKSIZE, 0, 0);
                     42:       BLKLOC(hp->listtail)->lelem.listnext.type = D_LELEM;
                     43:       BLKLOC(BLKLOC(hp->listtail)->lelem.listnext) = (union block *) bp;
                     44:       bp->listprev = hp->listtail;
                     45:       BLKLOC(hp->listtail) = (union block *) bp;
                     46:       }
                     47:    /*
                     48:     * Set i to position of new last element and assign val (arg2) to
                     49:     *  that element.
                     50:     */
                     51:    i = bp->first + bp->nused;
                     52:    if (i >= bp->nelem)
                     53:       i -= bp->nelem;
                     54:    bp->lslots[i] = arg2;
                     55:    /*
                     56:     * Adjust block usage count and current list size.
                     57:     */
                     58:    bp->nused++;
                     59:    hp->cursize++;
                     60:    /*
                     61:     * Return the list.
                     62:     */
                     63:    arg0 = arg1;
                     64:    }
                     65: 
                     66: Procblock(put,2)

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.