public static ushort gxPerm(ushort n, ushort k)
{
return(Support.permutation_nbits(n, k));
}
public void Parse(char[] fmt)
{
num.Clear();
stack.Clear();
try
{
foreach (char ch in fmt)
{
switch (ch)
{
/////////////// basic types
case char n when numbers.Contains(ch):
num.Extend(n);
break;
case '.': // set fracpart
num.ConvertFrac();
break;
case '-': // negate
num.Negate();
break;
case ',': // save arg
PushNum();
num.Clear();
break;
/////////////// higher level types
case 'n': // nil field
states[col].fmt = 'n';
states[col].bit_width = 0;
states[col].bit_mask = 0;
num.Clear();
break;
case 'b': // bits as integer: b,<bitlength>
states[col].fmt = (stack.Count == 0) ? 'b' : 'e';
states[col].bit_width = num.ExtractUInt();
states[col].bit_mask = (uint)(1 << (int)states[col].bit_width) - 1;
num.Clear();
break;
case 'f': // float: f,<offset>,<stepsize>,<stepcount>
states[col].fmt = (stack.Count == 2) ? 'f' : 'e';
states[col].float_offset = num.ExtractFloat(); // arg1
states[col].float_step = PopFloat(); // arg2
states[col].float_count = PopUInt(); // arg3
states[col].bit_width = Support.count_nbits(states[col].float_count);
states[col].bit_mask = (ulong)(1 << (int)states[col].bit_width) - 1;
num.Clear();
break;
case 'p': // permutation: p,<n>,<k>,<group>,<pick>
states[col].fmt = (stack.Count == 3) ? 'p' : 'e';
states[col].perm_n = num.ExtractUInt(); // arg1
states[col].perm_k = PopUInt(); // arg2;
states[col].perm_group = PopUInt(); // arg3;
states[col].perm_pick = PopUInt(); // arg4;
states[col].bit_width = Support.permutation_nbits(states[col].perm_n, states[col].perm_k);
states[col].bit_mask = (ulong)(1 << (int)states[col].bit_width) - 1;
num.Clear();
break;
}
}
}
catch
{
states[col].fmt = 'e'; // err
}
col++;
}
