value type_num_str(value f)
{
if (!f->L) return 0;
{
value x = arg(f->R);
if (x->T == type_num)
f = reduce_str(f,num_str(get_num(x)));
else
f = reduce_void(f);
drop(x);
return f;
}
}
/* (var_get var) returns val, where val is the current value of var. */
value type_var_get(value f)
{
if (!f->L) return 0;
{
value x = arg(f->R);
if (x->T == type_var)
f = hold(get_var(x));
else
f = reduce_void(f);
drop(x);
return f;
}
}
/* (fclose fh) Close the file handle. */
value type_fclose(value f)
{
if (!f->L) return 0;
{
value out = arg(f->R);
if (out->T == type_file)
{
fclose(get_fh(out));
f = hold(&QI);
}
else
f = reduce_void(f);
drop(out);
return f;
}
}
/* (remove path) Remove path from file system; return 0 if successful or -1
otherwise. */
value type_remove(value f)
{
if (!f->L) return 0;
{
value x = arg(f->R);
if (x->T == type_str)
{
string path = get_str(x);
int code = remove(path->data);
f = Qnum0(code);
}
else
f = reduce_void(f);
drop(x);
return f;
}
}
/* (var_put var val) replaces the value of the variable. */
value type_var_put(value f)
{
if (!f->L || !f->L->L) return 0;
{
value x = arg(f->L->R);
if (x->T == type_var)
{
value v = arg(f->R);
drop(x->R->R);
x->R->R = v;
f = hold(&QI);
}
else
f = reduce_void(f);
drop(x);
return f;
}
}
/* (fopen path mode) Open a file and return fh, where fh is the open file
handle or void on failure. */
value type_fopen(value f)
{
if (!f->L || !f->L->L) return 0;
{
value x = arg(f->L->R);
value y = arg(f->R);
if (x->T == type_str && y->T == type_str)
{
string path = get_str(x);
string mode = get_str(y);
FILE *fh = fopen(path->data,mode->data);
f = fh ? Qfile(fh) : hold(&Qvoid);
}
else
f = reduce_void(f);
drop(x);
drop(y);
return f;
}
}
static value op_flock(value f, int operation)
{
if (!f->L) return 0;
{
value x = arg(f->R);
if (x->T == type_file)
{
int code = flock(fileno(get_fh(x)),operation);
if (code < 0)
{
perror("flock");
die(0);
}
f = hold(&QI);
}
else
f = reduce_void(f);
drop(x);
return f;
}
}
/* (void x) = void */
value type_void(value f)
{
if (!f->L) return 0;
return reduce_void(f);
}
