Add wordy exercise (#157)

Author: ErikSchierboom

config.json

@@ -585,6 +585,22 @@
         ],
         "difficulty": 2
       },
+      {
+        "slug": "wordy",
+        "name": "Wordy",
+        "uuid": "fae36fc2-9c03-42a0-b1a1-3d1dd61783ba",
+        "practices": [
+          "numbers",
+          "strings",
+          "conditionals"
+        ],
+        "prerequisites": [
+          "numbers",
+          "strings",
+          "conditionals"
+        ],
+        "difficulty": 6
+      },
       {
         "slug": "perfect-numbers",
         "name": "Perfect Numbers",

exercises/practice/wordy/.docs/instructions.md

@@ -0,0 +1,59 @@
+# Instructions
+
+Parse and evaluate simple math word problems returning the answer as an integer.
+
+## Iteration 0 — Numbers
+
+Problems with no operations simply evaluate to the number given.
+
+> What is 5?
+
+Evaluates to 5.
+
+## Iteration 1 — Addition
+
+Add two numbers together.
+
+> What is 5 plus 13?
+
+Evaluates to 18.
+
+Handle large numbers and negative numbers.
+
+## Iteration 2 — Subtraction, Multiplication and Division
+
+Now, perform the other three operations.
+
+> What is 7 minus 5?
+
+2
+
+> What is 6 multiplied by 4?
+
+24
+
+> What is 25 divided by 5?
+
+5
+
+## Iteration 3 — Multiple Operations
+
+Handle a set of operations, in sequence.
+
+Since these are verbal word problems, evaluate the expression from left-to-right, _ignoring the typical order of operations._
+
+> What is 5 plus 13 plus 6?
+
+24
+
+> What is 3 plus 2 multiplied by 3?
+
+15  (i.e. not 9)
+
+## Iteration 4 — Errors
+
+The parser should reject:
+
+- Unsupported operations ("What is 52 cubed?")
+- Non-math questions ("Who is the President of the United States")
+- Word problems with invalid syntax ("What is 1 plus plus 2?")

exercises/practice/wordy/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "ErikSchierboom"
+  ],
+  "files": {
+    "solution": [
+      "src/wordy.cljs"
+    ],
+    "test": [
+      "test/wordy_test.cljs"
+    ],
+    "example": [
+      ".meta/src/example.cljs"
+    ]
+  },
+  "blurb": "Parse and evaluate simple math word problems returning the answer as an integer.",
+  "source": "Inspired by one of the generated questions in the Extreme Startup game.",
+  "source_url": "https://github.com/rchatley/extreme_startup"
+}

exercises/practice/wordy/.meta/src/example.cljs

@@ -0,0 +1,23 @@
+(ns wordy
+  (:require [clojure.string :refer [join]]))
+
+(def ^:private ops {"plus" +
+                    "minus" -
+                    "multiplied by" *
+                    "divided by" /})
+
+(def ^:private tokens-pattern (re-pattern
+                               (str (join "|" (keys ops)) "|-?\\d+|\\S+")))
+
+(defn- parse-op [op-str]
+  (or (ops op-str)
+      (throw (js/Error. (str "unknown operator " op-str)))))
+
+(defn evaluate [expr]
+  (if-let [[_ exprs] (re-matches #"What is (.+)\?" expr)]
+    (if-let [[token & tokens] (re-seq tokens-pattern exprs)]
+      (reduce (fn [acc [op x]]
+                ((parse-op op) acc (js/parseInt x)))
+              (js/parseInt token) (partition-all 2 tokens))
+      (throw (js/Error. "no arithmetic expression found")))
+    (throw (js/Error. "cannot recognize question"))))

exercises/practice/wordy/.meta/tests.toml

@@ -0,0 +1,72 @@
+# This is an auto-generated file. Regular comments will be removed when this
+# file is regenerated. Regenerating will not touch any manually added keys,
+# so comments can be added in a "comment" key.
+
+[88bf4b28-0de3-4883-93c7-db1b14aa806e]
+description = "just a number"
+
+[bb8c655c-cf42-4dfc-90e0-152fcfd8d4e0]
+description = "addition"
+
+[79e49e06-c5ae-40aa-a352-7a3a01f70015]
+description = "more addition"
+
+[b345dbe0-f733-44e1-863c-5ae3568f3803]
+description = "addition with negative numbers"
+
+[cd070f39-c4cc-45c4-97fb-1be5e5846f87]
+description = "large addition"
+
+[0d86474a-cd93-4649-a4fa-f6109a011191]
+description = "subtraction"
+
+[30bc8395-5500-4712-a0cf-1d788a529be5]
+description = "multiplication"
+
+[34c36b08-8605-4217-bb57-9a01472c427f]
+description = "division"
+
+[da6d2ce4-fb94-4d26-8f5f-b078adad0596]
+description = "multiple additions"
+
+[7fd74c50-9911-4597-be09-8de7f2fea2bb]
+description = "addition and subtraction"
+
+[b120ffd5-bad6-4e22-81c8-5512e8faf905]
+description = "multiple subtraction"
+
+[4f4a5749-ef0c-4f60-841f-abcfaf05d2ae]
+description = "subtraction then addition"
+
+[312d908c-f68f-42c9-aa75-961623cc033f]
+description = "multiple multiplication"
+
+[38e33587-8940-4cc1-bc28-bfd7e3966276]
+description = "addition and multiplication"
+
+[3c854f97-9311-46e8-b574-92b60d17d394]
+description = "multiple division"
+
+[3ad3e433-8af7-41ec-aa9b-97b42ab49357]
+description = "unknown operation"
+
+[8a7e85a8-9e7b-4d46-868f-6d759f4648f8]
+description = "Non math question"
+
+[42d78b5f-dbd7-4cdb-8b30-00f794bb24cf]
+description = "reject problem missing an operand"
+
+[c2c3cbfc-1a72-42f2-b597-246e617e66f5]
+description = "reject problem with no operands or operators"
+
+[4b3df66d-6ed5-4c95-a0a1-d38891fbdab6]
+description = "reject two operations in a row"
+
+[6abd7a50-75b4-4665-aa33-2030fd08bab1]
+description = "reject two numbers in a row"
+
+[10a56c22-e0aa-405f-b1d2-c642d9c4c9de]
+description = "reject postfix notation"
+
+[0035bc63-ac43-4bb5-ad6d-e8651b7d954e]
+description = "reject prefix notation"

exercises/practice/wordy/deps.edn

@@ -0,0 +1,10 @@
+{:deps
+ {org.clojure/clojure {:mvn/version "1.10.1"}
+  org.clojure/clojurescript {:mvn/version "1.10.773"}}
+
+ :aliases
+ {:test
+  {:extra-paths ["test"]
+   :extra-deps
+   {olical/cljs-test-runner {:mvn/version "3.8.0"}}
+   :main-opts ["-m" "cljs-test-runner.main"]}}}

exercises/practice/wordy/src/wordy.cljs

@@ -0,0 +1,5 @@
+(ns wordy)
+
+(defn evaluate [] ;; <- arglist goes here
+      ;; your code goes here
+)

exercises/practice/wordy/test/wordy_test.cljs

@@ -0,0 +1,56 @@
+(ns wordy-test
+  (:require [clojure.test :refer [deftest is]]
+            wordy))
+
+(deftest addition
+  (is (= (wordy/evaluate "What is 1 plus 1?") 2)))
+
+(deftest more-addition
+  (is (= (wordy/evaluate "What is 53 plus 2?") 55)))
+
+(deftest addition-with-negative-numbers
+  (is (= (wordy/evaluate "What is -1 plus -10?") -11)))
+
+(deftest large-addition
+  (is (= (wordy/evaluate "What is 123 plus 45678?") 45801)))
+
+(deftest subtraction
+  (is (= (wordy/evaluate "What is 4 minus -12?") 16)))
+
+(deftest multiplication
+  (is (= (wordy/evaluate "What is -3 multiplied by 25?") -75)))
+
+(deftest division
+  (is (= (wordy/evaluate "What is 33 divided by -3?") -11)))
+
+(deftest multiple-additions
+  (is (= (wordy/evaluate "What is 1 plus 1 plus 1?") 3)))
+
+(deftest addition-and-subtraction
+  (is (= (wordy/evaluate "What is 1 plus 5 minus -2?") 8)))
+
+(deftest multiple-subtraction
+  (is (= (wordy/evaluate "What is 20 minus 4 minus 13?") 3)))
+
+(deftest subtraction-then-addition
+  (is (= (wordy/evaluate "What is 17 minus 6 plus 3?") 14)))
+
+(deftest multiple-multiplication
+  (is (= (wordy/evaluate "What is 2 multiplied by -2 multiplied by 3?") -12)))
+
+(deftest addition-and-multiplication
+  (is (= (wordy/evaluate "What is -3 plus 7 multiplied by -2?") -8)))
+
+(deftest multiple-division
+  (is (= (wordy/evaluate "What is -12 divided by 2 divided by -3?") 2)))
+
+(deftest unknown-operation
+  (is (thrown?
+       js/Error
+       (wordy/evaluate "What is 52 cubed?"))))
+
+(deftest Non-math-question
+  (is (thrown?
+       js/Error
+       (wordy/evaluate "Who is the President of the United States?"))))
+