void Token_stream::unget(Token t)
{
if(full) {
switch(buffer.kind) {
case SQRT:
sputback(SSQRT);
break;
case LET:
sputback(SLET);
break;
case QUIT:
sputback(SQUIT);
break;
case HELP:
sputback(SHELP);
case VAR:
case NUMBER:
sputback(buffer.name);
break;
default:
cin.putback(buffer.kind);
break;
}
}
full=true;
buffer=t;
}
/* convenience of reusing procedures that take 1 state parameter */
static int
zreadhexstring_at(i_ctx_t *i_ctx_p, os_ptr op, uint start, int odd)
{
stream *s;
uint len, nread;
byte *str;
int odd_byte = odd;
stream_cursor_write cw;
int status;
check_read_file(s, op - 1);
/*check_write_type(*op, t_string); *//* done by caller */
str = op->value.bytes;
len = r_size(op);
cw.ptr = str + start - 1;
cw.limit = str + len - 1;
for (;;) {
status = s_hex_process(&s->cursor.r, &cw, &odd_byte,
hex_ignore_garbage);
if (status == 1) { /* filled the string */
ref_assign_inline(op - 1, op);
make_true(op);
return 0;
} else if (status != 0) /* error or EOF */
break;
/* Didn't fill, keep going. */
status = spgetc(s);
if (status < 0)
break;
sputback(s);
}
nread = cw.ptr + 1 - str;
if (status != EOFC) { /* Error */
nread |= odd_byte << 24;
return handle_read_status(i_ctx_p, status, op - 1, &nread,
zreadhexstring_continue);
}
/* Reached end-of-file before filling the string. */
/* Return an appropriate substring. */
ref_assign_inline(op - 1, op);
r_set_size(op - 1, nread);
make_false(op);
return 0;
}