// Calc passes input to clac and returns the calculated result.
func Calc(in, out *bort.Message) error {
out.Type = bort.PrivMsg
cl.Reset()
cmdReader := strings.NewReader(in.Args)
isHex := false
for {
tok := ""
if _, err := fmt.Fscan(cmdReader, &tok); err != nil {
if err != io.EOF {
return err
}
break
}
switch tok { // special cases
case "help":
out.Target = in.Nick
out.Text = helpStr
return nil
case "hex":
isHex = true
continue
}
num, err := clac.ParseNum(tok)
if err == nil {
if err = cl.Exec(func() error { return cl.Push(num) }); err != nil {
return fmt.Errorf("push: %s", err)
}
continue
}
if cmd, ok := cmdMap[tok]; ok {
if err = cl.Exec(cmd); err != nil {
return fmt.Errorf("calc: %s: invalid input", tok)
}
continue
}
return fmt.Errorf("calc: %s: invalid input", tok)
}
stack := cl.Stack()
if len(stack) == 0 {
return errors.New("empty stack")
}
ans := ""
for i := range stack {
val := stack[len(stack)-i-1]
if isHex {
if math.Abs(val) >= 1<<53 {
ans += "overflow"
} else {
ans += fmt.Sprintf("%#x", int64(val))
}
} else {
ans += fmt.Sprintf("%g", val)
}
if i < len(stack)-1 {
ans += " "
}
}
out.Text = ans
return nil
}
