From 3913b3c4f314f100f53fb72009e51fee6c9cf7da Mon Sep 17 00:00:00 2001
From: Jacob Signorovitch <jsignorovitch@commschool.org>
Date: Tue, 12 Nov 2024 12:56:58 -0500
Subject: [PATCH] Added Generics.

---
 generics/.classpath                           | 12 +++
 generics/.project                             | 17 ++++
 .../org.eclipse.core.resources.prefs          |  2 +
 generics/.settings/org.eclipse.jdt.core.prefs | 11 +++
 generics/src/generics/Main.java               | 77 +++++++++++++++++++
 5 files changed, 119 insertions(+)
 create mode 100644 generics/.classpath
 create mode 100644 generics/.project
 create mode 100644 generics/.settings/org.eclipse.core.resources.prefs
 create mode 100644 generics/.settings/org.eclipse.jdt.core.prefs
 create mode 100644 generics/src/generics/Main.java

diff --git a/generics/.classpath b/generics/.classpath
new file mode 100644
index 0000000..f9ed317
--- /dev/null
+++ b/generics/.classpath
@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-21">
+		<attributes>
+			<attribute name="module" value="true"/>
+		</attributes>
+	</classpathentry>
+	<classpathentry kind="src" path="src"/>
+	<classpathentry kind="lib" path="/home/jacob/School/CS3/libs/javalib.jar"/>
+	<classpathentry kind="lib" path="/home/jacob/School/CS3/libs/tester.jar"/>
+	<classpathentry kind="output" path="bin"/>
+</classpath>
diff --git a/generics/.project b/generics/.project
new file mode 100644
index 0000000..520a6cf
--- /dev/null
+++ b/generics/.project
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>generics</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.eclipse.jdt.core.javanature</nature>
+	</natures>
+</projectDescription>
diff --git a/generics/.settings/org.eclipse.core.resources.prefs b/generics/.settings/org.eclipse.core.resources.prefs
new file mode 100644
index 0000000..99f26c0
--- /dev/null
+++ b/generics/.settings/org.eclipse.core.resources.prefs
@@ -0,0 +1,2 @@
+eclipse.preferences.version=1
+encoding/<project>=UTF-8
diff --git a/generics/.settings/org.eclipse.jdt.core.prefs b/generics/.settings/org.eclipse.jdt.core.prefs
new file mode 100644
index 0000000..9a7984b
--- /dev/null
+++ b/generics/.settings/org.eclipse.jdt.core.prefs
@@ -0,0 +1,11 @@
+eclipse.preferences.version=1
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=21
+org.eclipse.jdt.core.compiler.codegen.unusedLocal=preserve
+org.eclipse.jdt.core.compiler.compliance=21
+org.eclipse.jdt.core.compiler.debug.lineNumber=generate
+org.eclipse.jdt.core.compiler.debug.localVariable=generate
+org.eclipse.jdt.core.compiler.debug.sourceFile=generate
+org.eclipse.jdt.core.compiler.problem.enablePreviewFeatures=disabled
+org.eclipse.jdt.core.compiler.problem.reportPreviewFeatures=warning
+org.eclipse.jdt.core.compiler.release=enabled
+org.eclipse.jdt.core.compiler.source=21
diff --git a/generics/src/generics/Main.java b/generics/src/generics/Main.java
new file mode 100644
index 0000000..84a16a0
--- /dev/null
+++ b/generics/src/generics/Main.java
@@ -0,0 +1,77 @@
+package generics;
+
+import tester.Tester;
+
+class Examples {
+    ILo<Integer> mint = new Mt<Integer>();
+    ILo<Integer> lint = new Cons<Integer>(1, new Cons<Integer>(92, new Cons<Integer>(-12, mint)));
+    ILo<Integer> lint2 = new Cons<Integer>(1, new Cons<Integer>(1, mint));
+    
+    ILo<String> mstr = new Mt<String>();
+    ILo<String> hello = new Cons<String>("Hello, ", mstr);
+    ILo<String> world = new Cons<String>("world.", mstr);
+    ILo<String> ajcmsdj = new Cons<String>("ajcmsdj", mstr);
+    ILo<String> helloWorld = new Cons<String>("Hello, ", new Cons<String>("world.", mstr));
+    ILo<String> helloAjcmsdj = new Cons<String>("Hello, ", ajcmsdj);
+    
+    boolean testILoAppend(Tester t) {
+        return t.checkExpect(hello.append(world), helloWorld) &&
+                        t.checkExpect(lint.append(mint), lint) &&
+                        t.checkExpect(mint.append(lint), lint);
+    }
+    
+    boolean testILoArmax(Tester t) {
+        return t.checkExpect(helloWorld.argmax(new IEvaluator<StrLen>()), "Hello, ")
+                        && t.checkExpect(helloAjcmsdj.argmax(new IEvaluator<StrLen>()), "Hello, ")
+                        && t.checkExpect(lint2.argmax(new IEvaluator<IntSize>()), 1)
+                        && t.checkExpect(lint.argmax(new IEvaluator<IntSize>()), 92);
+    }
+    
+    
+}
+
+// Generic function.
+interface IFunc<X, Y> {
+    Y apply(X input);
+}
+
+// Calculate the length of a string.
+class StrLen implements IFunc<String, Integer> { public Integer apply(String input) {
+    return input.length();
+}}
+
+// Calculate the size of an integer.
+class IntSize implements IFunc<Integer, Integer> { public Integer apply(Integer input) {
+    return input - 14;
+}}
+
+// Extracts the value of an input.
+interface IEvaluator<X> extends IFunc<X, Integer> {}
+
+interface ILo<A> { 
+    ILo<A> append(ILo<A> a);
+    A argmax(IEvaluator<A> eval);
+}
+
+class Cons<A> implements ILo<A> {
+    A first;
+    ILo<A> rest;
+    
+    Cons(A first, ILo<A> rest) {
+        this.first = first;
+        this.rest = rest;
+    }
+    
+    public ILo<A> append(ILo<A> a) { return new Cons<A>(this.first, this.rest.append(a)); }
+    
+    public A argmax(IEvaluator<A> eval) {
+        return null;
+    }
+}
+
+class Mt<A> implements ILo<A> {
+    public ILo<A> append(ILo<A> a) { return a; }
+    public A argmax(IEvaluator<A> eval) {
+        throw new UnsupportedOperationException("No max of empty list.");
+    }
+}