ref: 8a788aea84aad3bfbd5b39d78c1925654f3b9e14
dir: /appl/lib/sets32.b/
implement Sets;
include "sys.m";
sys: Sys;
include "sets32.m";
init()
{
sys = load Sys Sys->PATH;
}
set(): Set
{
return Set(0);
}
BITS: con 32;
MSB: con 1 << (BITS - 1);
Set.X(s1: self Set, o: int, s2: Set): Set
{
return Set(op(o, s1.s, s2.s));
}
Set.invert(s: self Set): Set
{
return Set(~s.s);
}
Set.add(s: self Set, n: int): Set
{
return Set(s.s | (1 << n));
}
Set.del(s: self Set, n: int): Set
{
return Set(s.s & ~(1 << n));
}
Set.addlist(s: self Set, ns: list of int): Set
{
for (; ns != nil; ns = tl ns)
s.s |= (1 << hd ns);
return s;
}
Set.holds(s: self Set, n: int): int
{
return s.s & (1 << n);
}
Set.str(s: self Set): string
{
msb := s.s >> (BITS - 1);
# discard all top bits that are the same as msb
t := 16rf << (BITS - 4);
sig := 8;
while (t != 0) {
if ((msb & t) != (s.s & t))
break;
sig--;
t = (t >> 4) & 16r0fffffff; # logical shift right
}
str: string;
if (sig > 0) {
top := ~MSB & s.s;
if (sig < 8) # shifting left by 32 bits is undefined.
top &= (1 << (sig << 2)) - 1;
str = sys->sprint("%.*ux", sig, top);
}
return str + ":" + string (msb & 1);
}
Set.bytes(s: self Set, n: int): array of byte
{
m := (s.limit() >> 3) + 1;
if(m > n)
n = m;
d := array[n] of byte;
case len d {
1 =>
d[0] = byte s.s;
2 =>
d[0] = byte s.s;
d[1] = byte (s.s >> 8);
3 =>
d[0] = byte s.s;
d[1] = byte (s.s >> 8);
d[2] = byte (s.s >> 16);
4 =>
d[0] = byte s.s;
d[1] = byte (s.s >> 8);
d[2] = byte (s.s >> 16);
d[3] = byte (s.s >> 24);
* =>
d[0] = byte s.s;
d[1] = byte (s.s >> 8);
d[2] = byte (s.s >> 16);
d[3] = byte (s.s >> 24);
msb := byte (s.s >> (BITS - 1)); # sign extension
for(i := 4; i < len d; i++)
d[i] = msb;
}
return d;
}
bytes2set(d: array of byte): Set
{
if(len d == 0)
return Set(0);
msb := ~(int (d[len d - 1] >> 7) - 1);
v: int;
case len d {
1 =>
v = int d[0] | (msb & int 16rffffff00);
2 =>
v = int d[0] | (int d[1] << 8) | (msb & int 16rffff0000);
3 =>
v = int d[0] | (int d[1] << 8) | (int d[2] << 16) | (msb & int 16rff000000);
* or # XXX could raise (or return) an error for len d > 4
4 =>
v = int d[0] | (int d[1] << 8) | (int d[2] << 16) | (int d[3] << 24);
}
return Set(v);
}
Set.debugstr(s: self Set): string
{
return sys->sprint("%ux", s.s);
}
Set.eq(s1: self Set, s2: Set): int
{
return s1.s == s2.s;
}
Set.isempty(s: self Set): int
{
return s.s == 0;
}
Set.msb(s: self Set): int
{
return (s.s & MSB) != 0;
}
Set.limit(s: self Set): int
{
m := s.s >> (BITS - 1); # sign extension
return topbit(s.s ^ m);
}
topbit(v: int): int
{
if (v == 0)
return 0;
(b, n, mask) := (1, 16, int 16rffff0000);
while (n != 0) {
if (v & mask) {
b += n;
v >>= n; # could return if v==0 here if we thought it worth it
}
n >>= 1;
mask >>= n;
}
return b;
}
str2set(str: string): Set
{
n := len str;
if (n < 2 || str[n - 2] != ':')
return Set(0);
c := str[n - 1];
if (c != '0' && c != '1')
return Set(0);
n -= 2;
msb := ~(c - '1');
# XXX should we give some sort of error if there
# are more bits than we can hold?
return Set((hex2int(str[0:n], msb) & ~MSB) | (msb & MSB));
}
hex2int(s: string, fill: int): int
{
n := fill;
for (i := 0; i < len s; i++) {
c := s[i];
if (c >= '0' && c <= '9')
c -= '0';
else if (c >= 'a' && c <= 'f')
c -= 'a' - 10;
else if (c >= 'A' && c <= 'F')
c -= 'A' - 10;
else
c = 0;
n = (n << 4) | c;
}
return n;
}
op(o: int, a, b: int): int
{
case o & 2r1111 {
2r0000 => return 0;
2r0001 => return ~(a | b);
2r0010 => return a & ~b;
2r0011 => return ~b;
2r0100 => return ~a & b;
2r0101 => return ~a;
2r0110 => return a ^ b;
2r0111 => return ~(a & b);
2r1000 => return a & b;
2r1001 => return ~(a ^ b);
2r1010 => return a;
2r1011 => return a | ~b;
2r1100 => return b;
2r1101 => return ~a | b;
2r1110 => return a | b;
2r1111 => return ~0;
}
return 0;
}