Chapter 3 done

madsravn · Nov 5, 2023 · c9862d4 · c9862d4
1 parent 895b4a3
commit c9862d4
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Showing 5 changed files with 64 additions and 17 deletions.
diff --git a/.github/workflows/maven.yml b/.github/workflows/maven.yml
@@ -31,13 +31,13 @@ jobs:
       run: mvn -B package --file pom.xml
     - name: Test with Maven
       run: mvn -B test --file pom.xml
-  checkstyle:
-    name: runner / checkstyle
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: dbelyaev/action-checkstyle@master
-        with:
-          github_token: ${{ secrets.token }}
-          reporter: github-check
-          level: warning
+        #checkstyle:
+        #name: runner / checkstyle
+        #runs-on: ubuntu-latest
+        #steps:
+        #- uses: actions/checkout@v4
+        #- uses: dbelyaev/action-checkstyle@master
+        #with:
+        #github_token: ${{ secrets.token }}
+        #reporter: github-check
+        #level: warning
diff --git a/src/main/java/dk/madsravn/interpreter/evaluator/Evaluator.java b/src/main/java/dk/madsravn/interpreter/evaluator/Evaluator.java
@@ -263,6 +263,33 @@ private static List<IObject> evaluateExpressions(List<IExpression> expressions,
         return result;
     }
 
+    private static IObject applyFunction(IObject function, List<IObject> arguments) {
+        if(function instanceof FunctionObject) {
+            FunctionObject functionObject = (FunctionObject) function;
+            Environment extendedEnvironment = extendFunctionEnvironment(functionObject, arguments);
+            IObject evaluated = evaluate(functionObject.getBody(), extendedEnvironment);
+            return unwrapReturnValue(evaluated);
+        } else {
+            return ErrorObject.notAFunction(function.type());
+        }
+    }
+
+    private static Environment extendFunctionEnvironment(FunctionObject function, List<IObject> arguments) {
+        Environment env = new Environment(function.getEnvironment());
+        for(int i = 0; i < function.getParametersLength(); ++i) {
+            env.set(function.getParameters().get(i).getValue(), arguments.get(i));
+        }
+        return env;
+    }
+
+    private static IObject unwrapReturnValue(IObject object) {
+        if(object instanceof ReturnObject) {
+            ReturnObject returnObject = (ReturnObject) object;
+            return returnObject.getValue();
+        }
+        return object;
+    }
+
     private static boolean isError(IObject object) {
         return (object instanceof ErrorObject);
     }

diff --git a/src/main/java/dk/madsravn/interpreter/object/Environment.java b/src/main/java/dk/madsravn/interpreter/object/Environment.java
@@ -6,22 +6,34 @@
 
 public class Environment {
     private Map<String, IObject> store;
-    private Map<String, IObject> outerStore;
+    // TODO: Is Optional the correct solution here?
+    private Optional<Environment> outerStore;
 
     public Environment() {
         store = new HashMap<String, IObject>();
-        outerStore = new HashMap<String, IObject>();
+        outerStore = Optional.empty();
     }
 
-    public Environment(Map<String, IObject> outerStore) {
+    public Environment(Environment outerStore) {
         store = new HashMap<String, IObject>();
-        this.outerStore = outerStore;
+        this.outerStore = Optional.of(outerStore);
     }
 
+    //TODO: UGLY AS HELL
     public Optional<IObject> get(String name) {
-        return Optional.ofNullable(
-                Optional.ofNullable(store.get(name)).orElse(outerStore.get(name))
-        );
+        //return Optional.ofNullable(store.get(name)).orElse(Optional.ofNullable(outerStore.get(name).get()));
+        var first = store.get(name);
+        if(first != null) {
+            return Optional.ofNullable(first);
+        } else {
+            if(outerStore.isPresent()) {
+                var second = outerStore.get().get(name);
+                if (second.isPresent()) {
+                    return second;
+                }
+            }
+        }
+        return Optional.empty();
     }
 
     public IObject set(String name, IObject value) {

diff --git a/src/main/java/dk/madsravn/interpreter/object/ErrorObject.java b/src/main/java/dk/madsravn/interpreter/object/ErrorObject.java
@@ -15,6 +15,10 @@ public static ErrorObject identifierNotFoundError(String message) {
         return new ErrorObject("identifier not found: " + message);
     }
 
+    public static ErrorObject notAFunction(String message) {
+        return new ErrorObject("not a function: " + message);
+    }
+
     public ErrorObject(String message) {
         this.message = message;
     }

diff --git a/src/main/java/dk/madsravn/interpreter/object/FunctionObject.java b/src/main/java/dk/madsravn/interpreter/object/FunctionObject.java
@@ -29,6 +29,10 @@ public BlockStatement getBody() {
         return body;
     }
 
+    public Environment getEnvironment() {
+        return env;
+    }
+
     @Override
     public String type() {
         return OBJ_TYPE;