package repl

import (
    "bufio"
    "fmt"
    "github/runnignwater/monkey/lexer"
    "github/runnignwater/monkey/token"
    "io"
)

/**
 * @Author: simon
 * @Author: ynwdlxm@163.com
 * @Date: 2022/10/2 下午5:41
 * @Desc: REPL that tokenizes Monkey source code and prints the tokens
 */

const PROMPT = ">>> "

func Start(in io.Reader, out io.Writer) {
    scanner := bufio.NewScanner(in)

    for {
        fmt.Printf(PROMPT)
        scan := scanner.Scan()
        if !scan {
            return
        }
        line := scanner.Text()

        l := lexer.New(line)

        for tok := l.NextToken(); tok.Type != token.EOF; tok = l.NextToken() {
            fmt.Printf("%+v\n", tok)
        }
    }
}