ref: 75c92428225428c8fde2d015f010e608a0b12f1d
dir: purgatorio/appl/cmd/tr.b
implement Tr;
include "sys.m";
sys: Sys;
include "draw.m";
include "bufio.m";
bufio: Bufio;
Iobuf: import bufio;
include "arg.m";
arg: Arg;
Tr: module
{
init: fn(nil: ref Draw->Context, nil: list of string);
};
Pcb: adt { # Control block controlling specification parse
spec: string; # specification string
end: int; # its length
current: int; # current parse point
last: int; # last Rune returned
final: int; # final Rune in a span
new: fn(nil: string): ref Pcb;
rewind: fn(nil: self ref Pcb);
getc: fn(nil: self ref Pcb): int;
canon: fn(nil: self ref Pcb): int;
};
bits := array [] of { byte 1, byte 2, byte 4, byte 8, byte 16, byte 32, byte 64, byte 128 };
SETBIT(a: array of byte, c: int)
{
a[c>>3] |= bits[c & 7];
}
CLEARBIT(a: array of byte, c: int)
{
a[c>>3] &= ~bits[c & 7];
}
BITSET(a: array of byte, c: int): int
{
return int (a[c>>3] & bits[c&7]);
}
f := array[(Sys->Runemax+1)/8] of byte;
t := array[(Sys->Runemax+1)/8] of byte;
pto, pfrom: ref Pcb;
cflag := 0;
dflag := 0;
sflag := 0;
stderr: ref Sys->FD;
ib: ref Iobuf;
ob: ref Iobuf;
usage()
{
sys->fprint(stderr, "Usage: tr [-sdc] [from-set [to-set]]\n");
raise "fail: usage";
}
init(nil: ref Draw->Context, args: list of string)
{
sys = load Sys Sys->PATH;
stderr = sys->fildes(2);
bufio = load Bufio Bufio->PATH;
arg = load Arg Arg->PATH;
arg->init(args);
while((c := arg->opt()) != 0)
case c {
's' => sflag = 1;
'd' => dflag = 1;
'c' => cflag = 1;
* => usage();
}
args = arg->argv();
argc := len args;
if(args != nil){
pfrom = Pcb.new(hd args);
args = tl args;
}
if(args != nil){
pto = Pcb.new(hd args);
args = tl args;
}
if(args != nil)
usage();
ib = bufio->fopen(sys->fildes(0), Bufio->OREAD);
ob = bufio->fopen(sys->fildes(1), Bufio->OWRITE);
if(dflag) {
if(sflag && argc != 2 || !sflag && argc != 1)
usage();
delete();
} else {
if(argc != 2)
usage();
if(cflag)
complement();
else
translit();
}
if(ob.flush() == Bufio->ERROR)
error(sys->sprint("write error: %r"));
}
delete()
{
if (cflag) {
for(i := 0; i < len f; i++)
f[i] = byte 16rFF;
while ((c := pfrom.canon()) >= 0)
CLEARBIT(f, c);
} else {
while ((c := pfrom.canon()) >= 0)
SETBIT(f, c);
}
if (sflag) {
while ((c := pto.canon()) >= 0)
SETBIT(t, c);
}
last := Sys->Runemax+1;
while ((c := ib.getc()) >= 0) {
if(!BITSET(f, c) && (c != last || !BITSET(t,c))) {
last = c;
ob.putc(c);
}
}
}
complement()
{
lastc := 0;
high := 0;
while ((from := pfrom.canon()) >= 0) {
if (from > high)
high = from;
SETBIT(f, from);
}
while ((cto := pto.canon()) >= 0) {
if (cto > high)
high = cto;
SETBIT(t,cto);
}
pto.rewind();
p := array[high+1] of int;
for (i := 0; i <= high; i++){
if (!BITSET(f,i)) {
if ((cto = pto.canon()) < 0)
cto = lastc;
else
lastc = cto;
p[i] = cto;
} else
p[i] = i;
}
if (sflag){
lastc = Sys->Runemax+1;
while ((from = ib.getc()) >= 0) {
if (from > high)
from = cto;
else
from = p[from];
if (from != lastc || !BITSET(t,from)) {
lastc = from;
ob.putc(from);
}
}
} else {
while ((from = ib.getc()) >= 0){
if (from > high)
from = cto;
else
from = p[from];
ob.putc(from);
}
}
}
translit()
{
lastc := 0;
high := 0;
while ((from := pfrom.canon()) >= 0)
if (from > high)
high = from;
pfrom.rewind();
p := array[high+1] of int;
for (i := 0; i <= high; i++)
p[i] = i;
while ((from = pfrom.canon()) >= 0) {
if ((cto := pto.canon()) < 0)
cto = lastc;
else
lastc = cto;
if (BITSET(f,from) && p[from] != cto)
error("ambiguous translation");
SETBIT(f,from);
p[from] = cto;
SETBIT(t,cto);
}
while ((cto := pto.canon()) >= 0)
SETBIT(t,cto);
if (sflag){
lastc = Sys->Runemax+1;
while ((from = ib.getc()) >= 0) {
if (from <= high)
from = p[from];
if (from != lastc || !BITSET(t,from)) {
lastc = from;
ob.putc(from);
}
}
} else {
while ((from = ib.getc()) >= 0) {
if (from <= high)
from = p[from];
ob.putc(from);
}
}
}
Pcb.new(s: string): ref Pcb
{
return ref Pcb(s, len s, 0, -1, -1);
}
Pcb.rewind(p: self ref Pcb)
{
p.current = 0;
p.last = p.final = -1;
}
Pcb.getc(p: self ref Pcb): int
{
if(p.current >= p.end)
return -1;
s := p.current;
r := p.spec[s++];
if(r == '\\' && s < p.end){
n := 0;
if ((r = p.spec[s]) == 'x') {
s++;
for (i := 0; i < 6 && s < p.end; i++) {
p.current = s;
r = p.spec[s++];
if ('0' <= r && r <= '9')
n = 16*n + r - '0';
else if ('a' <= r && r <= 'f')
n = 16*n + r - 'a' + 10;
else if ('A' <= r && r <= 'F')
n = 16*n + r - 'A' + 10;
else {
if (i == 0)
return 'x';
return n;
}
}
r = n;
} else {
for(i := 0; i < 3 && s < p.end; i++) {
p.current = s;
r = p.spec[s++];
if('0' <= r && r <= '7')
n = 8*n + r - '0';
else {
if (i == 0)
return r;
return n;
}
}
if(n > 0377)
error("char>0377");
r = n;
}
}
p.current = s;
return r;
}
Pcb.canon(p: self ref Pcb): int
{
if (p.final >= 0) {
if (p.last < p.final)
return ++p.last;
p.final = -1;
}
if (p.current >= p.end)
return -1;
if(p.spec[p.current] == '-' && p.last >= 0 && p.current+1 < p.end){
p.current++;
r := p.getc();
if (r < p.last)
error ("Invalid range specification");
if (r > p.last) {
p.final = r;
return ++p.last;
}
}
r := p.getc();
p.last = r;
return p.last;
}
error(s: string)
{
sys->fprint(stderr, "tr: %s\n", s);
raise "fail: error";
}