package erjang.m.io_lib;
import erjang.BIF;
import erjang.EBitString;
import erjang.EInteger;
import erjang.ENative;
import erjang.EObject;
import erjang.ERT;
import erjang.EString;
import erjang.ESeq;
import erjang.ESmall;
public class Native extends ENative {
/** Emulate io_lib:write_binary_body(), but without using deep stack. */
@BIF
static public EObject write_binary_body(EObject arg1, EObject arg2)
{
EBitString bin = arg1.testBitString();
EInteger d = arg2.testInteger();
if (bin == null || d == null)
throw ERT.badarg(arg1, arg2);
int depth = d.intValue();
if (depth < 0) depth=Integer.MAX_VALUE;
ESeq builder = ERT.NIL;
long bitCount = bin.bitSize();
if (bitCount > 8*(depth-1)) {
// Replace tail with ellipsis:
builder = builder.cons(EString.fromString("..."));
} else if (bitCount % 8 > 0) {
// Handle tail bits
int tailBitCount = (int)(bitCount & 7);
int tailBits = bin.intBitsAt(bitCount & (~7), tailBitCount);
builder = builder.cons(EString.fromString(String.valueOf(tailBitCount)));
builder = builder.cons(ESmall.make(':'));
builder = builder.cons(EString.fromString(String.valueOf(tailBits)));
}
// Handle whole bytes:
for (long bitPos=8*(Math.min(bitCount/8, depth-1)-1);
bitPos>=0;
bitPos-=8)
{
if (bitPos < bitCount-8) {
builder = builder.cons(ESmall.make(','));
}
String byteAsIntString = String.valueOf(bin.intBitsAt(bitPos, 8));
builder = builder.cons(EString.fromString(byteAsIntString));
}
return builder;
}
}