let

Bind a variable

Given a file named “main.scm” with:

(import (scheme base))

(write-u8 (let ((x 65)) x))

When I successfully run stak main.scm

Then the stdout should contain exactly “A”.

Bind two variables

Given a file named “main.scm” with:

(import (scheme base))

(write-u8 (let ((x 60) (y 5)) (+ x y)))

When I successfully run stak main.scm

Then the stdout should contain exactly “A”.

Call a bound procedure

Given a file named “main.scm” with:

(import (scheme base))

(define (f) 65)

(define (g)
  (let ((h f))
    (h)))

(write-u8 (g))

When I successfully run stak main.scm

Then the stdout should contain exactly “A”.

Cause a side effect in a body

Given a file named “main.scm” with:

(import (scheme base))

(write-u8
  (let ((x 66))
    (write-u8 65)
    x))

When I successfully run stak main.scm

Then the stdout should contain exactly “AB”.

Do not corrupt a procedure environment

Given a file named “main.scm” with:

(import (scheme base))

(define (f)
  (let (
      (g
        (let ((x 65))
          (lambda () x))))
    g))

(write-u8 ((f)))

When I successfully run stak main.scm

Then the stdout should contain exactly “A”.