Add dot-dsl exercise

Closes #1809

config.json

@@ -1802,6 +1802,16 @@
           "if-statements"
         ],
         "difficulty": 5
+      },
+      {
+        "slug": "dot-dsl",
+        "name": "DOT DSL",
+        "uuid": "03e1070d-a3ed-4664-9559-283e535c6bc4",
+        "practices": [],
+        "prerequisites": [
+          "classes"
+        ],
+        "difficulty": 5
       }
     ],
     "foregone": [

exercises/practice/dot-dsl/.docs/instructions.md

@@ -0,0 +1,30 @@
+# Instructions
+
+A [Domain Specific Language (DSL)][dsl] is a small language optimized for a specific domain.
+Since a DSL is targeted, it can greatly impact productivity/understanding by allowing the writer to declare _what_ they want rather than _how_.
+
+One problem area where they are applied are complex customizations/configurations.
+
+For example the [DOT language][dot-language] allows you to write a textual description of a graph which is then transformed into a picture by one of the [Graphviz][graphviz] tools (such as `dot`).
+A simple graph looks like this:
+
+    graph {
+        graph [bgcolor="yellow"]
+        a [color="red"]
+        b [color="blue"]
+        a -- b [color="green"]
+    }
+
+Putting this in a file `example.dot` and running `dot example.dot -T png -o example.png` creates an image `example.png` with red and blue circle connected by a green line on a yellow background.
+
+Write a Domain Specific Language similar to the Graphviz dot language.
+
+Our DSL is similar to the Graphviz dot language in that our DSL will be used to create graph data structures.
+However, unlike the DOT Language, our DSL will be an internal DSL for use only in our language.
+
+More information about the difference between internal and external DSLs can be found [here][fowler-dsl].
+
+[dsl]: https://en.wikipedia.org/wiki/Domain-specific_language
+[dot-language]: https://en.wikipedia.org/wiki/DOT_(graph_description_language)
+[graphviz]: https://graphviz.org/
+[fowler-dsl]: https://martinfowler.com/bliki/DomainSpecificLanguage.html

exercises/practice/dot-dsl/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "kahgoh"
+  ],
+  "files": {
+    "solution": [
+      "src/main/java/DotDsl.java"
+    ],
+    "test": [
+      "src/test/java/DotDslTest.java"
+    ],
+    "example": [
+      ".meta/src/reference/java/DotDsl.java"
+    ]
+  },
+  "blurb": "Write a Domain Specific Language similar to the Graphviz dot language.",
+  "source": "Wikipedia",
+  "source_url": "https://en.wikipedia.org/wiki/DOT_(graph_description_language)"
+}

exercises/practice/dot-dsl/.meta/src/reference/java/DotDsl.java

@@ -0,0 +1,108 @@
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public class DotDsl {
+    private static class Element<T> {
+        private final Map<String, String> attributes = new HashMap<>();
+
+        public Element() {
+        }
+
+        public Element(Map<String, String> attributes) {
+            this.attributes.putAll(attributes);
+        }
+
+        public Map<String, String> getAttributes() {
+            return Collections.unmodifiableMap(attributes);
+        }
+    }
+
+    public static class Graph extends Element<Graph> {
+
+        private final List<Node> nodes = new ArrayList<>();
+
+        private final List<Edge> edges = new ArrayList<>();
+
+        public Graph() {
+            super();
+        }
+
+        public Graph(Map<String, String> attributes) {
+            super(attributes);
+        }
+
+        public Collection<Node> getNodes() {
+            return Collections.unmodifiableList(nodes);
+        }
+
+        public Collection<Edge> getEdges() {
+            return Collections.unmodifiableList(edges);
+        }
+
+        public Graph node(String name) {
+            nodes.add(new Node(name));
+            return this;
+        }
+
+        public Graph node(String name, Map<String, String> attributes) {
+            nodes.add(new Node(name, attributes));
+            return this;
+        }
+
+        public Graph edge(String start, String end) {
+            edges.add(new Edge(start, end));
+            return this;
+        }
+
+        public Graph edge(String start, String end, Map<String, String> attributes) {
+            edges.add(new Edge(start, end, attributes));
+            return this;
+        }
+    }
+
+    public static class Node extends Element<Node> {
+        private final String name;
+
+        public Node(String name) {
+            this.name = name;
+        }
+
+        public Node(String name, Map<String, String> attributes) {
+            super(attributes);
+            this.name = name;
+        }
+
+        public String getName() {
+            return name;
+        }
+    }
+
+    public static class Edge extends Element<Edge> {
+        private final String start;
+
+        private final String end;
+
+        public Edge(String start, String end) {
+            this.start = start;
+            this.end = end;
+        }
+
+        public Edge(String start, String end, Map<String, String> attributes) {
+            super(attributes);
+            this.start = start;
+            this.end = end;
+        }
+
+        public String getStart() {
+            return start;
+        }
+
+        public String getEnd() {
+            return end;
+        }
+    }
+}

exercises/practice/dot-dsl/build.gradle

@@ -0,0 +1,23 @@
+plugins {
+    id "java"
+}
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    testImplementation platform("org.junit:junit-bom:5.10.0")
+    testImplementation "org.junit.jupiter:junit-jupiter"
+    testImplementation "org.assertj:assertj-core:3.25.1"
+}
+
+test {
+    useJUnitPlatform()
+
+    testLogging {
+        exceptionFormat = "full"
+        showStandardStreams = true
+        events = ["passed", "failed", "skipped"]
+    }
+}

exercises/practice/dot-dsl/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,6 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.7-bin.zip
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists