Mixing
RackUnit check-eq? returns false for equal Strings
I am a little bit puzzled with RackUnit's check-eq? returning false for equal strings.
This is the code I am trying:
#lang racket
(require rackunit)
(define (get-output proc)
(let ([out (open-output-string)])
(parameterize ([current-output-port out])
(proc)
(get-output-string out))))
(define output (get-output
(λ () (display "hello"))))
(check-eq? output "hello")
Running this test results in this error:
--------------------
. FAILURE
name: check-eq?
location: unsaved-editor:14:0
actual: "hello"
expected: "hello"
--------------------
I thought I understood the meaning of eq? but it seems I'm still missing something... why is this failing?
I know that get-output-string calls bytes->string/utf8, which returns something that passes the string? contract, so I assumed this should work when comparing to a literal string.
racket rackunit
asked Nov 19 '18 at 19:28
RenatoRenato
6,60023348
add a comment |
I am a little bit puzzled with RackUnit's check-eq? returning false for equal strings.
This is the code I am trying:
#lang racket
(require rackunit)
(define (get-output proc)
(let ([out (open-output-string)])
(parameterize ([current-output-port out])
(proc)
(get-output-string out))))
(define output (get-output
(λ () (display "hello"))))
(check-eq? output "hello")
Running this test results in this error:
--------------------
. FAILURE
name: check-eq?
location: unsaved-editor:14:0
actual: "hello"
expected: "hello"
--------------------
I thought I understood the meaning of eq? but it seems I'm still missing something... why is this failing?
I know that get-output-string calls bytes->string/utf8, which returns something that passes the string? contract, so I assumed this should work when comparing to a literal string.
racket rackunit
asked Nov 19 '18 at 19:28
RenatoRenato
6,60023348
add a comment |
I am a little bit puzzled with RackUnit's check-eq? returning false for equal strings.
This is the code I am trying:
#lang racket
(require rackunit)
(define (get-output proc)
(let ([out (open-output-string)])
(parameterize ([current-output-port out])
(proc)
(get-output-string out))))
(define output (get-output
(λ () (display "hello"))))
(check-eq? output "hello")
Running this test results in this error:
--------------------
. FAILURE
name: check-eq?
location: unsaved-editor:14:0
actual: "hello"
expected: "hello"
--------------------
I thought I understood the meaning of eq? but it seems I'm still missing something... why is this failing?
I know that get-output-string calls bytes->string/utf8, which returns something that passes the string? contract, so I assumed this should work when comparing to a literal string.
racket rackunit
asked Nov 19 '18 at 19:28
RenatoRenato
6,60023348
I am a little bit puzzled with RackUnit's check-eq? returning false for equal strings.
This is the code I am trying:
#lang racket
(require rackunit)
(define (get-output proc)
(let ([out (open-output-string)])
(parameterize ([current-output-port out])
(proc)
(get-output-string out))))
(define output (get-output
(λ () (display "hello"))))
(check-eq? output "hello")
Running this test results in this error:
--------------------
. FAILURE
name: check-eq?
location: unsaved-editor:14:0
actual: "hello"
expected: "hello"
--------------------
I thought I understood the meaning of eq? but it seems I'm still missing something... why is this failing?
I know that get-output-string calls bytes->string/utf8, which returns something that passes the string? contract, so I assumed this should work when comparing to a literal string.
racket rackunit
racket rackunit
asked Nov 19 '18 at 19:28
RenatoRenato
6,60023348
asked Nov 19 '18 at 19:28
RenatoRenato
6,60023348
asked Nov 19 '18 at 19:28
RenatoRenato
6,60023348
asked Nov 19 '18 at 19:28
RenatoRenato
6,60023348
asked Nov 19 '18 at 19:28
RenatoRenato
6,60023348
6,60023348
add a comment |
add a comment |
1 Answer
1
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oldest
votes
Oh, looks like I mixed up eq? and equal?...
eq? compares by memory reference.
The more lenient one is the longer one, equal? which compares by value, roughly.
The docs, as usual, explain this quite well. Here more details about eq?, equal? and their weird friend, eqv?.
answered Nov 19 '18 at 19:35
RenatoRenato
6,60023348
add a comment |
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1 Answer
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active
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votes
1 Answer
1
active
oldest
votes
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oldest
votes
active
oldest
votes
Oh, looks like I mixed up eq? and equal?...
eq? compares by memory reference.
The more lenient one is the longer one, equal? which compares by value, roughly.
The docs, as usual, explain this quite well. Here more details about eq?, equal? and their weird friend, eqv?.
answered Nov 19 '18 at 19:35
RenatoRenato
6,60023348
add a comment |
Oh, looks like I mixed up eq? and equal?...
eq? compares by memory reference.
The more lenient one is the longer one, equal? which compares by value, roughly.
The docs, as usual, explain this quite well. Here more details about eq?, equal? and their weird friend, eqv?.
answered Nov 19 '18 at 19:35
RenatoRenato
6,60023348
add a comment |
Oh, looks like I mixed up eq? and equal?...
eq? compares by memory reference.
The more lenient one is the longer one, equal? which compares by value, roughly.
The docs, as usual, explain this quite well. Here more details about eq?, equal? and their weird friend, eqv?.
answered Nov 19 '18 at 19:35
RenatoRenato
6,60023348
Oh, looks like I mixed up eq? and equal?...
eq? compares by memory reference.
The more lenient one is the longer one, equal? which compares by value, roughly.
The docs, as usual, explain this quite well. Here more details about eq?, equal? and their weird friend, eqv?.
answered Nov 19 '18 at 19:35
RenatoRenato
6,60023348
answered Nov 19 '18 at 19:35
RenatoRenato
6,60023348
answered Nov 19 '18 at 19:35
RenatoRenato
6,60023348
answered Nov 19 '18 at 19:35
RenatoRenato
6,60023348
6,60023348
add a comment |
add a comment |
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