标签: racket eval
#lang plait number: DIGIT number eval(0) = 0 eval(1) = 1 eval(2) = 2 ... eval(9) = 9 eval(DIGIT) = DIGIT eval(DIGIT number) = 10*eval(DIGIT) + eval(number)
Racket的文档指出eval仅可在DrRacket的交互窗口中使用。如何在定义窗口中编写此代码?
eval