Mac-Source 1994 July/Mac-Source_July_1994.iso/C and C++/Compilers⁄Interps/kevoSource/lists.c

Text File | 1993-05-08 | 5KB | 217 lines

/* Kevo -- a prototype-based object-oriented language */
/* (c) Antero Taivalsaari 1991-1993                   */
/* Some parts (c) Antero Taivalsaari 1986-1988           */
/* lists.c: Dynamically growing lists (needed in various places) */

#include "global.h"

/*--------------------------------------------------------------------------*/
/* List management operations */

/* createList(): create a new empty list */

LIST* createList()
{
  /* Allocate object */
  LIST*  newList = (LIST*)mymalloc(sizeof(LIST));
  STORE* newStore  = createStore(DATAOFFSET+1); /* OOP cells plus one data cell */

    /* Set the fields needed for closure objects */
    newList->mfa = newStore;                 /* Storage part for storing list data */
    newList->logicalSize = 0;                  /* Initially list is empty */
    newList->physicalSize = DATAOFFSET+1;    /* One slot is allocated, though */

    /* Make the list a full-fledged OOP object by storing */
    /* the appropriate values to the two first slots */
    newStore->efa = (int*)oContext;
    newStore->pfa = (int*)dummyContext;

    return(newList);
}


/* deleteList(): delete an existing list */

void deleteList(list)
LIST* list;
{
    free((STORE*)list->mfa);
    free(list);
}


/* for debugging :

void printList(list)
LIST* list;
{
  int* store = (int*)list->mfa;
  int  i;

    printf("List: %d contents:\n\t", list);
    for (i = DATAOFFSET; i < list->logicalSize+DATAOFFSET; i++) printf("%d ", store[i]);
    printf("\n");
}
*/


/* addToList(): add a new value to a list */

void addToList(list, value)
LIST* list;
void* value;
{
  int  index = list->logicalSize+DATAOFFSET; /* New items are added to the end */
  int* store;

    /* For safety, zero values cannot be stored */
    if (value == 0) return;

    /* Extend the list in chunks of four cells */
    if (index >= list->physicalSize) {
        list->mfa = (STORE*)myrealloc(list->mfa, (list->physicalSize+4)*CELL);
        list->physicalSize += 4;
    }

    store = (int*)list->mfa;
    store[index] = (int)value;

    list->logicalSize++;

#ifdef DEBUG
    printf("Adding %d.\n", value);
    printList(list);
#endif
}


/* condAddToList: conditionally add a new value to a list */
/* (only if the value is not previously in the list) */

void condAddToList(list, value)
LIST* list;
void* value;
{
    if (!findInList(list, value)) addToList(list, value);
}


/* Remove a value from a list.
    Return true if the value is found (and removed) in the list, false otherwise.
*/

int removeFromList(list, value)
LIST* list;
void* value;
{
    int index = findInList(list, value);

    if (index) {
      int* store = (int*)list->mfa;

        index += DATAOFFSET;

        /* Move the rest of the list downwards */
        while(index < list->logicalSize+DATAOFFSET) {
            store[index-1] = store[index];
            index++;
        }

        list->logicalSize--;

        /* Store zero to the last (now unused) position just in case */
        store[list->logicalSize+DATAOFFSET] = 0;

#ifdef DEBUG
        printf("Removing %d.\n", value);
        printList(list);
#endif
        return(TRUE);
    }
    else return(FALSE);
}


/* storeToList(): store a value to a list */
/*
void storeToList(list, index, value)
LIST* list;
int      index;
void* value;
{
  int* store = (int*)list->mfa;

    index++;    Physical indexes begin from two, user indexes from one

    if (index >= DATAOFFSET && index < list->logicalSize+DATAOFFSET)
        store[index] = (int)value;
    else {
        fprintf(confile, "== Integrity error detected (out of bounds in LIST store) ==\n");
        reportIntegrityError();
        ownLongJmp();
    }
} */


/* fetchFromList(): fetch a value from a list */

void* fetchFromList(list, index)
LIST* list;
int      index;
{
  int*  store = (int*)list->mfa;

    index++;    /* Physical indexes begin from two (DATAOFFSET), user indexes from one */

    if (index >= DATAOFFSET && index < list->logicalSize+DATAOFFSET)
        return((void*)store[index]);
    else {
        fprintf(confile, "== Integrity error detected (out of bounds in LIST fetch) ==\n");
        reportIntegrityError();
        ownLongJmp();
    }
}


/* findInList(): check if a certain value can be found in a list */

int findInList(list, value)
LIST* list;
void* value;
{
  int   limit  = list->logicalSize+DATAOFFSET;
  int*  store = (int*)list->mfa;
  int   i;

    for (i = DATAOFFSET; i < limit; i++) {
        if (store[i] == (int)value) return(i-1);
    }
    return(0);
}


/* emptyList(): erase an existing list to zero */

void emptyList(list)
LIST* list;
{
    if (list->physicalSize != DATAOFFSET+1) {
        list->mfa = (STORE*)myrealloc(list->mfa, (DATAOFFSET+1)*CELL);
        list->physicalSize = DATAOFFSET+1;
    }
    list->logicalSize = 0;
}


/* optimizeList(): minimize the memory consumption of a list */

void optimizeList(list)
LIST* list;
{
    if (list->physicalSize > list->logicalSize+DATAOFFSET) {
        list->mfa = (STORE*)myrealloc(list->mfa, (list->logicalSize+DATAOFFSET)*CELL);
        list->physicalSize = list->logicalSize+DATAOFFSET;
    }
}