func NewRule(name string, r io.Reader) (*Rule, error) {
data, err := ioutil.ReadAll(r)
if err != nil {
return nil, err
}
fset := twik.NewFileSet()
scope := NewGlobalScope(fset)
node, err := twik.Parse(fset, name, data)
if err != nil {
return nil, err
}
return &Rule{
Name: name,
program: node,
scope: scope,
lock: &sync.Mutex{},
}, nil
}
func run() error {
fset := twik.NewFileSet()
scope := twik.NewDefaultScope(fset)
scope.Create("printf", printfFn)
scope.Create("list", listFn)
if len(os.Args) > 1 {
if strings.HasPrefix(os.Args[1], "-") {
return fmt.Errorf("usage: twik [<source file>]")
}
f, err := os.Open(os.Args[1])
if err != nil {
return err
}
defer f.Close()
data, err := ioutil.ReadAll(f)
if err != nil {
return err
}
node, err := twik.Parse(fset, os.Args[1], data)
if err != nil {
return err
}
_, err = scope.Eval(node)
return err
}
state, err := terminal.MakeRaw(1)
if err != nil {
return err
}
defer terminal.Restore(1, state)
t := terminal.NewTerminal(os.Stdout, "> ")
unclosed := ""
for {
line, err := t.ReadLine()
if err == io.EOF {
break
}
if err != nil {
return err
}
if unclosed != "" {
line = unclosed + "\n" + line
}
unclosed = ""
t.SetPrompt("> ")
node, err := twik.ParseString(fset, "", line)
if err != nil {
if strings.HasSuffix(err.Error(), "missing )") {
unclosed = line
t.SetPrompt(". ")
continue
}
fmt.Println(err)
continue
}
value, err := scope.Eval(node)
if err != nil {
fmt.Println(err)
continue
}
if value != nil {
if reflect.TypeOf(value).Kind() == reflect.Func {
fmt.Println("#func")
} else if v, ok := value.([]interface{}); ok {
if len(v) == 0 {
fmt.Println("()")
} else {
fmt.Print("(list")
for _, e := range v {
fmt.Printf(" %#v", e)
}
fmt.Println(")")
}
} else {
fmt.Printf("%#v\n", value)
}
}
}
fmt.Println()
return nil
}