Write

Write a byte

Given a file named “main.scm” with:

(import (scheme base))

(write-u8 65)

When I successfully run stak main.scm

Then the stdout should contain exactly “A”.

Write a character

Given a file named “main.scm” with:

(import (scheme base))

(write-char #\<value>)

When I successfully run stak main.scm

Then the stdout should contain exactly “<value>”.

Examples

value
a
A
~

Write a multi-byte character

Given a file named “main.scm” with:

(import (scheme base))

(write-char #\<value>)

When I successfully run stak main.scm

Then the stdout should contain exactly “<value>”.

Examples

value
д
∰
😄

Write an escaped character

Given a file named “main.scm” with:

(import (scheme base) (scheme write))

(write <value>)

When I successfully run stak main.scm

Then the stdout should contain exactly “<output>”.

Examples

value	output
#\a	#\a
#\A	#\A
#(	#\(
##	#\#

Write an escaped special character

Given a file named “main.scm” with:

(import (scheme base) (scheme write))

(write <value>)

When I successfully run stak main.scm

Then the stdout should contain exactly “<output>”.

Examples

value	output
#\alarm	#\alarm
#\backspace	#\backspace
#\delete	#\delete
#\escape	#\escape
#\newline	#\newline
#\null	#\null
#\return	#\return
#\space	#\space
#\tab	#\tab

Write a string

Given a file named “main.scm” with:

(import (scheme base))

(write-string "Hello, world!")

When I successfully run stak main.scm

Then the stdout should contain exactly “Hello, world!”.

Write a special character in a string

Given a file named “main.scm” with:

(import (scheme base))

(write-string "<value>")

When I successfully run stak main.scm

Then the stdout should contain exactly “<value>”.

Examples

value
\n
\t
"

Write a boolean

Given a file named “main.scm” with:

(import (scheme base) (scheme write))

(write <value>)

When I successfully run stak main.scm

Then the stdout should contain exactly “<value>”.

Examples

value
#f
#t

Write a list

Given a file named “main.scm” with:

(import (scheme base) (scheme write))

(write '<value>)

When I successfully run stak main.scm

Then the stdout should contain exactly “<value>”.

Examples

value
()
(1)
(1 2)
(1 2 3)
(1 (1 2) (3 4 5))
(1 . 2)
(1 2 . 3)

Write a number

Given a file named “main.scm” with:

(import (scheme base) (scheme write))

(write <value>)

When I successfully run stak main.scm

Then the stdout should contain exactly “<value>”.

Examples

value
0
1
42
-1
-42

Write a procedure

Given a file named “main.scm” with:

(import (scheme base) (scheme write))

(write (lambda () #f))

When I successfully run stak main.scm

Then the stdout should contain exactly “#procedure”.

Write a record

Given a file named “main.scm” with:

(import (scheme base) (scheme write))

(define-record-type foo
  (make-foo)
  foo?)

(write (make-foo))

When I successfully run stak main.scm

Then the stdout should contain exactly “#record”.

Write a quoted string

Given a file named “main.scm” with:

(import (scheme base) (scheme write))

(write "<value>")

When I successfully run stak main.scm

Then the stdout should contain exactly “"<output>"”.

Examples

value	output
foo	foo
Hello, world!	Hello, world!
\n	\n
\t	\t
\r	\r
\n\t\r	\n\t\r

Write a symbol

Given a file named “main.scm” with:

(import (scheme base) (scheme write))

(write 'foo)

When I successfully run stak main.scm

Then the stdout should contain exactly “foo”.

Write an empty symbol

Given a file named “main.scm” with:

(import (scheme base) (scheme write))

(write (string->symbol ""))

When I successfully run stak main.scm

Then the stdout should contain exactly “||”.

Write a vector

Given a file named “main.scm” with:

(import (scheme base) (scheme write))

(write <value>)

When I successfully run stak main.scm

Then the stdout should contain exactly “<value>”.

Examples

value
#()
#(1)
#(1 2)
#(1 2 3)
#(1 #(1 2) #(3 4 5))

Write a byte vector

Given a file named “main.scm” with:

(import (scheme base) (scheme write))

(write <value>)

When I successfully run stak main.scm

Then the stdout should contain exactly “<value>”.

Examples

value
#u8()
#u8(1)
#u8(1 2)
#u8(1 2 3)

Write to a port

Given a file named “main.scm” with:

(import (scheme base) (scheme write))

(write '(42 foo #f) (current-output-port))

When I successfully run stak main.scm

Then the stdout should contain exactly “(42 foo #f)”.

Write a quote

Given a file named “main.scm” with:

(import (scheme base) (scheme write))

(write '<value>)

When I successfully run stak main.scm

Then the stdout should contain exactly “<value>”.

Examples

value
’()
`()
`(,1)
(quote)
(quasiquote)
(unquote)
(quote . 42)
(quasiquote . 42)
(unquote . 42)

Write a value in a collection

Given a file named “main.scm” with:

(import (scheme base) (scheme write))

(write '<value>)

When I successfully run stak main.scm

Then the stdout should contain exactly “<output>”.

Examples

value	output
(#\a)	(#\a)
(#\space)	(#\space)
(“foo”)	("foo")
((#\a))	((#\a))
((#\space))	((#\space))
((“foo”))	(("foo"))
#(#\a)	#(#\a)
#(#\space)	#(#\space)
#(“foo”)	#("foo")
#(#(#\a))	#(#(#\a))
#(#(#\space))	#(#(#\space))
#(#(“foo”))	#(#("foo"))

Display a value

Given a file named “main.scm” with:

(import (scheme base) (scheme write))

(display '<value>)

When I successfully run stak main.scm

Then the stdout should contain exactly “<output>”.

Examples

value	output
#\a	a
“foo”	foo
(#\a)	(a)
(#\space)	( )
(“foo”)	(foo)
((#\a))	((a))
((#\space))	(( ))
((“foo”))	((foo))
#(#\a)	#(a)
#(#\space)	#( )
#(“foo”)	#(foo)
#(#(#\a))	#(#(a))
#(#(#\space))	#(#( ))
#(#(“foo”))	#(#(foo))

Flush a port

Given a file named “main.scm” with:

(import (scheme base))

(flush-output-port)

When I successfully run stak main.scm

Then the exit status should be 0.

Recursive values

Write a recursive pair

Given a file named “main.scm” with:

(import (scheme base) (scheme write))

(define x (cons 42 #f))
(set-cdr! x x)

(<procedure> x)

When I successfully run stak main.scm

Then the stdout should contain exactly “#0=(42 . #0#)”.

Examples

procedure
write
write-shared

Write recursive pairs

Given a file named “main.scm” with:

(import (scheme base) (scheme write))

(define x (cons (cons 123 #f) (cons #f 42)))
(set-cdr! (car x) x)
(set-car! (cdr x) (cdr x))

(<procedure> x)

When I successfully run stak main.scm

Then the stdout should contain exactly “#0=((123 . #0#) . #1=(#1# . 42))”.

Examples

procedure
write
write-shared

Write a recursive vector

Given a file named “main.scm” with:

(import (scheme base) (scheme write))

(define x (vector 42 #f))
(vector-set! x 1 x)

(<procedure> x)

When I successfully run stak main.scm

Then the stdout should contain exactly “#0=#(42 #0#)”.

Examples

procedure
write
write-shared

Shared values

Write a shared pair

Given a file named “main.scm” with:

(import (scheme base) (scheme write))

(define x (cons 42 #f))

(<procedure> (cons x x))

When I successfully run stak main.scm

Then the stdout should contain exactly “<output>”.

Examples

procedure	output
write	((42 . #f) 42 . #f)
write-shared	(#0=(42 . #f) . #0#)

Write a shared vector

Given a file named “main.scm” with:

(import (scheme base) (scheme write))

(define x #(42 #f))

(<procedure> (vector x x))

When I successfully run stak main.scm

Then the stdout should contain exactly “<output>”.

Examples

procedure	output
write	#(#(42 #f) #(42 #f))
write-shared	#(#0=#(42 #f) #0#)