# Require in htdp/bsl
**URL:** https://racket.discourse.group/t/require-in-htdp-bsl/3988
**Category:** Questions & Answers
**Tags:** teaching
**Created:** [October 28, 2025, 12:59pm UTC](https://racket.discourse.group/t/require-in-htdp-bsl/3988 "2025-10-28T12:59:04Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@ToddOBryan](https://racket.discourse.group/u/ToddOBryan)
#### Post date: [October 28, 2025, 12:59pm UTC](https://racket.discourse.group/t/require-in-htdp-bsl/3988/1 "2025-10-28T12:59:05Z")
How could I allow students to use `read` and `display` in BSL?
I've tried `(require (only-in racket/base read))` but get an error saying that the module has to be a string or a `lib` or `planet` form.
I know why they're not provided in BSL and I mostly agree with that reasoning, but when you're trapped by an AP curriculum that thinks they're a fundamental part of what programming and computation are, you have to adapt. Basically, I have rubrics that specify that input and output have to be external to the program itself, so students wouldn't get full credit for a test case, but would if they `read` the check and `display` the expect.
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### Author:  [@soegaard](https://racket.discourse.group/u/soegaard)
#### Post date: [October 28, 2025, 1:05pm UTC](https://racket.discourse.group/t/require-in-htdp-bsl/3988/2 "2025-10-28T13:05:01Z")
You could follow the lead of the "convert" TeachPack.
> **[1.3 Converting Temperatures: "convert.rkt"](https://docs.racket-lang.org/teachpack/convert.html)**
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### Author:  [@shhyou](https://racket.discourse.group/u/shhyou)
#### Post date: [October 28, 2025, 1:05pm UTC](https://racket.discourse.group/t/require-in-htdp-bsl/3988/3 "2025-10-28T13:05:57Z")
What we've been doing is to provide our own `lib.rkt` that re-exports the needed functions to the students (either through a package or an accompanying file).
`#lang htdp/asl` also provides `read`, `write` and `display`, but then variables become mutable and functions can be nullary which might not be desired.
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### Author:  [@EmEf](https://racket.discourse.group/u/EmEf)
#### Post date: [October 28, 2025, 2:19pm UTC](https://racket.discourse.group/t/require-in-htdp-bsl/3988/4 "2025-10-28T14:19:32Z")
1. @shhyou solution works, and I recommend this approach to students who use ISL+ in my junior-level PL course:
(a) create a module `#lang racket (provide whatever you need)`
(b) (require "my-favorite-file.rkt")
1. I would recommend a look at 2htdp/batch-io. It is a teach pack that provides I/O in a way that fits into BSL. I have used it this way in our introductory course.
2. ASL has become a somewhat unsupported language. I recommend against using it.
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### Author:  [@ToddOBryan](https://racket.discourse.group/u/ToddOBryan)
#### Post date: [October 28, 2025, 4:28pm UTC](https://racket.discourse.group/t/require-in-htdp-bsl/3988/5 "2025-10-28T16:28:24Z")
Thanks for the suggestions. I'll take a look.