Postgres95 1.01 Distribution - Virgin Sources

src/backend/nodes/list.c

@@ -0,0 +1,438 @@
+/*-------------------------------------------------------------------------
+ *
+ * list.c--
+ *    various list handling routines
+ *
+ * Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *    $Header: /cvsroot/pgsql/src/backend/nodes/list.c,v 1.1.1.1 1996/07/09 06:21:32 scrappy Exp $
+ *
+ * NOTES
+ *    XXX a few of the following functions are duplicated to handle
+ *	  List of pointers and List of integers separately. Some day,
+ *        someone should unify them. 		- ay 11/2/94
+ *    This file needs cleanup.
+ *
+ * HISTORY
+ *    AUTHOR		DATE		MAJOR EVENT
+ *    Andrew Yu		Oct, 1994	file creation
+ *
+ *-------------------------------------------------------------------------
+ */
+#include <stdarg.h>
+#include "postgres.h"
+#include "nodes/pg_list.h"
+#include "nodes/parsenodes.h"
+#include "utils/builtins.h"	/* for namecpy */
+#include "utils/elog.h"
+#include "utils/palloc.h"
+
+List *
+makeList(void *elem, ...)
+{
+    va_list args;
+    List *retval = NIL;
+    List *temp = NIL;
+    List *tempcons = NIL;
+
+    va_start(args, elem);
+
+    temp = elem;
+    while (temp != (void *) -1) {
+	temp = lcons(temp, NIL);
+	if (tempcons == NIL)
+	    retval = temp;
+	else
+	    lnext(tempcons) = temp;
+	tempcons = temp;
+
+	temp = va_arg(args, void *);
+    }
+
+    va_end(args);
+
+    return (retval);
+}
+
+List *
+lcons(void *datum, List *list)
+{
+    List *l = makeNode(List);
+    lfirst(l) = datum;
+    lnext(l) = list;
+    return l;
+}
+
+List *
+lappend(List *list, void *obj)
+{
+    return nconc(list, lcons(obj, NIL));
+}
+
+Value *
+makeInteger(long i)
+{
+    Value *v = makeNode(Value);
+    v->type = T_Integer;
+    v->val.ival = i;
+    return v;
+}
+
+Value *
+makeFloat(double d)
+{
+    Value *v = makeNode(Value);
+    v->type = T_Float;
+    v->val.dval = d;
+    return v;
+}
+
+Value *
+makeString(char *str)
+{
+    Value *v = makeNode(Value);
+    v->type = T_String;
+    v->val.str = str;
+    return v;
+}
+
+/* n starts with 0 */
+void *
+nth(int n, List *l)
+{
+    /* XXX assume list is long enough */
+    while(n > 0) {
+	l = lnext(l);
+	n--;
+    }
+    return lfirst(l);
+}
+
+/* this is here solely for rt_store. Get rid of me some day! */
+void
+set_nth(List *l, int n, void *elem)
+{
+    /* XXX assume list is long enough */
+    while(n > 0) {
+	l = lnext(l);
+	n--;
+    }
+    lfirst(l) = elem;
+    return;
+}
+
+int
+length(List *l)
+{
+    int i=0;
+    while(l!=NIL) {
+	l = lnext(l);
+	i++;
+    }
+    return i;
+}
+
+void
+freeList(List *list)
+{
+    while(list!=NIL) {
+	List *l = list;
+	list = lnext(list);
+	pfree(l);
+    }
+}
+
+/*
+ * below are for backwards compatibility
+ */
+List *
+append(List *l1, List *l2)
+{
+    List *newlist, *newlist2, *p;
+
+    if (l1==NIL)
+	return copyObject(l2);
+
+    newlist = copyObject(l1);
+    newlist2 = copyObject(l2);
+
+    for (p=newlist; lnext(p)!=NIL; p=lnext(p))
+	;
+    lnext(p) = newlist2;
+    return newlist;
+}
+
+/*
+ * below are for backwards compatibility
+ */
+List *
+intAppend(List *l1, List *l2)
+{
+    List *newlist, *newlist2, *p;
+
+    if (l1==NIL)
+	return listCopy(l2);
+
+    newlist = listCopy(l1);
+    newlist2 = listCopy(l2);
+
+    for (p=newlist; lnext(p)!=NIL; p=lnext(p))
+	;
+    lnext(p) = newlist2;
+    return newlist;
+}
+
+List *
+nconc(List *l1, List *l2)
+{
+    List *temp;
+
+    if (l1 == NIL)
+	return l2;
+    if (l2 == NIL)
+	return l1;
+    if (l1 == l2)
+	elog(WARN, "tryout to nconc a list to itself");
+
+    for (temp = l1; lnext(temp)!=NULL; temp = lnext(temp))
+	;
+    
+    lnext(temp) = l2;
+    return(l1);      /* list1 is now list1[]list2  */
+}
+
+
+List *
+nreverse(List *list)
+{
+    List *rlist = NIL;
+    List *p = NIL;
+    
+    if(list==NULL)
+	return(NIL);
+    
+    if (length(list) == 1)
+	return(list);
+    
+    for (p = list; p!=NULL; p = lnext(p)) {
+	rlist = lcons(lfirst(p),rlist);
+    }
+    
+    lfirst(list) = lfirst(rlist);
+    lnext(list)  = lnext(rlist);
+    return(list);
+}
+
+/*    
+ *    	same
+ *    
+ *    	Returns t if two lists contain the same elements.
+ *       now defined in lispdep.c
+ *
+ * XXX only good for IntList	-ay
+ */
+bool
+same(List *foo, List *bar)
+{
+    List *temp = NIL;
+    
+    if (foo == NULL)
+	return (bar==NULL);
+    if (bar == NULL)
+	return (foo==NULL);
+    if (length(foo) == length(bar)) {
+	foreach (temp,foo) {
+	    if (!intMember((int)lfirst(temp),bar))
+		return(false);
+	}
+	return(true);
+    }
+    return(false);
+    
+}	  
+
+List *
+LispUnion(List *foo, List *bar)
+{
+    List *retval = NIL;
+    List *i = NIL;
+    List *j = NIL;
+    
+    if (foo==NIL)
+	return(bar); /* XXX - should be copy of bar */
+    
+    if (bar==NIL)
+	return(foo); /* XXX - should be copy of foo */
+    
+    foreach (i,foo) {
+	foreach (j,bar) {
+	    if (! equal(lfirst(i), lfirst(j))) {
+		retval = lappend(retval,lfirst(i));
+		break;
+	    }
+	}
+    }
+    foreach(i,bar) {
+	retval = lappend(retval,lfirst(i));
+    }
+    
+    return(retval);
+}
+
+List *
+LispUnioni(List *foo, List *bar)
+{
+    List *retval = NIL;
+    List *i = NIL;
+    List *j = NIL;
+    
+    if (foo==NIL)
+	return(bar); /* XXX - should be copy of bar */
+    
+    if (bar==NIL)
+	return(foo); /* XXX - should be copy of foo */
+    
+    foreach (i,foo) {
+	foreach (j,bar) {
+	    if (lfirsti(i) != lfirsti(j)) {
+		retval = lappendi(retval,lfirst(i));
+		break;
+	    }
+	}
+    }
+    foreach(i,bar) {
+	retval = lappendi(retval, lfirsti(i));
+    }
+    
+    return(retval);
+}
+
+/*
+ * member()
+ * - nondestructive, returns t iff foo is a member of the list
+ *   bar
+ */
+bool
+member(void *foo, List *bar)
+{
+    List *i;
+    foreach (i,bar)
+	if (equal((Node*)(lfirst(i)),(Node*)foo))
+	    return(true);
+    return(false);
+}
+
+bool
+intMember(int foo, List *bar)
+{
+    List *i;
+    foreach (i,bar)
+	if (foo == (int)lfirst(i))
+	    return(true);
+    return(false);
+}
+
+/*
+ * lremove -
+ *    only does pointer comparisons. Removes 'elem' from the the linked list.
+ */
+List *
+lremove(void *elem, List *list)
+{
+    List *l;
+    List *prev = NIL;
+    List *result = list;
+
+    foreach(l, list) {
+	if (elem == lfirst(l))
+	    break;
+	prev = l;
+    }
+    if (l!=NULL) {
+	if (prev == NIL) {
+	    result = lnext(list);
+	} else {
+	    lnext(prev) = lnext(l);
+	}
+    }
+    return result;
+}
+	
+List *
+LispRemove(void *elem, List *list)
+{
+    List *temp = NIL;
+    List *prev = NIL;
+    
+    if (equal(elem, lfirst(list)))
+	return lnext(list);
+
+    temp = lnext(list);
+    prev = list;
+    while(temp!=NIL) {
+	if (equal(elem, lfirst(temp))) {
+	    lnext(prev) = lnext(temp);
+	    break;
+	}
+	temp = lnext(temp);
+	prev = lnext(prev);
+    }
+    return(list);
+}
+
+List *
+intLispRemove(int elem, List *list)
+{
+    List *temp = NIL;
+    List *prev = NIL;
+    
+    if (elem == (int)lfirst(list))
+	return lnext(list);
+
+    temp = lnext(list);
+    prev = list;
+    while(temp!=NIL) {
+	if (elem == (int)lfirst(temp)) {
+	    lnext(prev) = lnext(temp);
+	    break;
+	}
+	temp = lnext(temp);
+	prev = lnext(prev);
+    }
+    return(list);
+}
+
+List *
+set_difference(List *list1, List *list2)
+{
+    List *temp1 = NIL;
+    List *result = NIL;
+    
+    if (list2==NIL)
+	return(list1); 
+    
+    foreach (temp1, list1) {
+	if (!member(lfirst(temp1), list2))
+	    result = lappend(result, lfirst(temp1));
+    }
+    return(result);
+}
+
+List *
+set_differencei(List *list1, List *list2)
+{
+    List *temp1 = NIL;
+    List *result = NIL;
+    
+    if (list2==NIL)
+	return(list1); 
+    
+    foreach (temp1, list1) {
+	if (!intMember(lfirsti(temp1), list2))
+	    result = lappendi(result, lfirst(temp1));
+    }
+    return(result);
+}
+