repl.go

package repl

import (
  "bufio"
  "fmt"
  "io"
  "pizzascript/eval"
  "pizzascript/lexer"
  "pizzascript/parser"
)

const PROMPT = "\n>> "
// Start executes repl, to try PizzaScript with standard input/output
func Start(in io.Reader, out io.Writer) {
  scanner := bufio.NewScanner(in)
  for {
    fmt.Fprintf(out, PROMPT)
    scanned := scanner.Scan()
    if !scanned {
      return
    }
    line := scanner.Text()
    l := lexer.New(line)
    p := parser.New(l)
    e := eval.New(p)
    fmt.Println(e.Eval())
  }
}