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/***********************************************************************/
/* */
/* Caml Special Light */
/* */
/* Xavier Leroy, projet Cristal, INRIA Rocquencourt */
/* */
/* Copyright 1995 Institut National de Recherche en Informatique et */
/* Automatique. Distributed only by permission. */
/* */
/***********************************************************************/
/* $Id$ */
#include "fail.h"
#include "memory.h"
#include "misc.h"
#include "mlvalues.h"
#include "str.h"
/* Structural comparison on trees.
May loop on cyclic structures. */
static long compare_val(v1, v2)
value v1,v2;
{
tag_t t1, t2;
tailcall:
if (v1 == v2) return 0;
if (Is_long(v1) || Is_long(v2)) return Long_val(v1) - Long_val(v2);
/* If one of the objects is outside the heap (but is not an atom),
use address comparison. */
if ((!Is_atom(v1) && !Is_young(v1) && !Is_in_heap(v1)) ||
(!Is_atom(v2) && !Is_young(v2) && !Is_in_heap(v2)))
return v1 - v2;
t1 = Tag_val(v1);
t2 = Tag_val(v2);
if (t1 != t2) return (long)t1 - (long)t2;
switch(t1) {
case String_tag: {
mlsize_t len1, len2, len;
unsigned char * p1, * p2;
len1 = string_length(v1);
len2 = string_length(v2);
for (len = (len1 <= len2 ? len1 : len2),
p1 = (unsigned char *) String_val(v1),
p2 = (unsigned char *) String_val(v2);
len > 0;
len--, p1++, p2++)
if (*p1 != *p2) return (long)*p1 - (long)*p2;
return len1 - len2;
}
case Double_tag: {
double d1 = Double_val(v1);
double d2 = Double_val(v2);
if (d1 < d2) return -1; else if (d1 > d2) return 1; else return 0;
}
case Double_array_tag: {
mlsize_t sz1 = Wosize_val(v1);
mlsize_t sz2 = Wosize_val(v2);
mlsize_t i;
if (sz1 != sz2) return sz1 - sz2;
for (i = 0; i < sz1; i++) {
double d1 = Double_field(v1, i);
double d2 = Double_field(v2, i);
if (d1 < d2) return -1; else if (d1 > d2) return 1;
}
return 0;
}
case Abstract_tag:
case Final_tag:
invalid_argument("equal: abstract value");
case Closure_tag:
case Infix_tag:
invalid_argument("equal: functional value");
default: {
mlsize_t sz1 = Wosize_val(v1);
mlsize_t sz2 = Wosize_val(v2);
value * p1, * p2;
long res;
if (sz1 != sz2) return sz1 - sz2;
if (sz1 == 0) return 0;
for(p1 = Op_val(v1), p2 = Op_val(v2);
sz1 > 1;
sz1--, p1++, p2++) {
res = compare_val(*p1, *p2);
if (res != 0) return res;
}
v1 = *p1;
v2 = *p2;
goto tailcall;
}
}
}
value compare(v1, v2) /* ML */
value v1, v2;
{
return Val_long(compare_val(v1, v2));
}
value equal(v1, v2) /* ML */
value v1, v2;
{
return Val_int(compare_val(v1, v2) == 0);
}
value notequal(v1, v2) /* ML */
value v1, v2;
{
return Val_int(compare_val(v1, v2) != 0);
}
value lessthan(v1, v2) /* ML */
value v1, v2;
{
return Val_int(compare_val(v1, v2) < 0);
}
value lessequal(v1, v2) /* ML */
value v1, v2;
{
return Val_int(compare_val(v1, v2) <= 0);
}
value greaterthan(v1, v2) /* ML */
value v1, v2;
{
return Val_int(compare_val(v1, v2) > 0);
}
value greaterequal(v1, v2) /* ML */
value v1, v2;
{
return Val_int(compare_val(v1, v2) >= 0);
}
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