Add most of lab 6 content

journal/_src/posts/2022-09-28-lab-six.md

@@ -5,3 +5,9 @@
 In this lab I learned about using hash sets and json parsing in racket.
 <!-- more -->
 
+## Hash Sets
+I learned about how to create, access and how to perform operations around hash sets, such as retrieving a color when accessing the hash set with the key of a fruit. You can use them to keep track of counts of a given string, such as in the test module in the lab.
+
+## JSON Parsing
+
+To be filled

labs/L06/Lab6.rkt

@@ -0,0 +1,30 @@
+#lang racket
+
+(define ht (hash "apple" 'red "banana" 'yellow))
+
+(module+ test
+  (require rackunit)
+  (check-equal? (hash-ref ht "apple") 'red))
+
+(define ht2 (hash-set ht "coconut" 'brown))
+
+(module+ test
+  (check-equal? (hash-ref ht2 "coconut") 'brown)
+  (check-exn exn:fail? (lambda () (hash-ref ht "coconut"))))
+
+(define (census . lst)
+  (define (helper lst acc-hash)
+    (cond
+      [(empty? lst) (hash->list acc-hash)]
+      [else
+       (let* ([key (first lst)]
+              [current (hash-ref acc-hash key 0)])
+         (helper (rest lst) (hash-set acc-hash key (add1 current))))]))
+  (helper lst (hash)))
+
+(module+ test
+  (check-equal?
+   (sort (census 1 2 3 1 2) #:key car <) '((1 . 2) (2 . 2) (3 . 1)))
+  (check-equal?
+   (sort (census "aardvark" "dingo" "buffalo" "buffalo" "bear") #:key car string<?)
+   '(("aardvark" . 1) ("bear" . 1) ("buffalo" . 2) ("dingo" . 1))))

labs/L06/errors.json

@@ -0,0 +1,20 @@
+{
+  "errors": [
+    {
+      "status": "403",
+      "source": { "pointer": "/data/attributes/secret-powers" },
+      "detail": "Editing secret powers is not authorized on Sundays."
+    },
+    {
+      "status": "422",
+      "source": { "pointer": "/data/attributes/volume" },
+      "detail": "Volume does not, in fact, go to 11."
+    },
+    {
+      "status": "500",
+      "source": { "pointer": "/data/attributes/reputation" },
+      "title": "The backend responded with an error",
+      "detail": "Reputation service not responding after three requests."
+    }
+  ]
+}