From 516a606aabed940f993d91842fa1ce0d9cf6c43a Mon Sep 17 00:00:00 2001
From: Sameer Rahmani <lxsameer@gnu.org>
Date: Tue, 31 Dec 2019 18:00:30 +0000
Subject: [PATCH] eq fn has been added

---
 src/main/java/serene/simple/RootScope.java    | 12 +---
 src/main/java/serene/simple/SNumber.java      |  3 +
 src/main/java/serene/simple/TrueNode.java     |  2 +-
 src/main/java/serene/simple/builtin/EqFn.java | 59 +++++++++++++++++++
 4 files changed, 66 insertions(+), 10 deletions(-)
 create mode 100644 src/main/java/serene/simple/builtin/EqFn.java

diff --git a/src/main/java/serene/simple/RootScope.java b/src/main/java/serene/simple/RootScope.java
index ca63fad..ca65c33 100644
--- a/src/main/java/serene/simple/RootScope.java
+++ b/src/main/java/serene/simple/RootScope.java
@@ -22,14 +22,8 @@ package serene.simple;
 import java.util.HashMap;
 import java.util.Map;
 
-import serene.simple.builtin.PrintlnFn;
-import serene.simple.builtin.QuitFn;
-import serene.simple.builtin.PlusFn;
-import serene.simple.builtin.MinusFn;
-import serene.simple.builtin.TimesFn;
-import serene.simple.builtin.ObelusFn;
-import serene.simple.builtin.ModFn;
-import serene.simple.builtin.NewFn;
+import serene.simple.builtin.*;
+
 
 public class RootScope extends AScope {
 
@@ -41,6 +35,7 @@ public class RootScope extends AScope {
       put("*", new TimesFn());
       put("/", new ObelusFn());
       put("mod", new ModFn());
+      put("=", new EqFn());
       put("System", System.class);
       put("Boolean", Boolean.class);
       put("String", String.class);
@@ -48,7 +43,6 @@ public class RootScope extends AScope {
     }};
 
 
-  // "mod", ModFn,
   // "now", NowFn,;
 
   public RootScope() {
diff --git a/src/main/java/serene/simple/SNumber.java b/src/main/java/serene/simple/SNumber.java
index 958fcd4..c74aa7f 100644
--- a/src/main/java/serene/simple/SNumber.java
+++ b/src/main/java/serene/simple/SNumber.java
@@ -150,6 +150,9 @@ public class SNumber {
     }
   }
 
+  /**
+   * Double number implementation.
+   */
   public static class DoubleNumber  implements IOps  {
     private Double v;
 
diff --git a/src/main/java/serene/simple/TrueNode.java b/src/main/java/serene/simple/TrueNode.java
index 43c5ff3..bb1e0ba 100644
--- a/src/main/java/serene/simple/TrueNode.java
+++ b/src/main/java/serene/simple/TrueNode.java
@@ -22,7 +22,7 @@ package serene.simple;
 public class TrueNode extends Node {
     @Override
     public Object eval(IScope scope) {
-        return true;
+        return Boolean.TRUE;
     }
 
     @Override
diff --git a/src/main/java/serene/simple/builtin/EqFn.java b/src/main/java/serene/simple/builtin/EqFn.java
new file mode 100644
index 0000000..59435f4
--- /dev/null
+++ b/src/main/java/serene/simple/builtin/EqFn.java
@@ -0,0 +1,59 @@
+/**
+ * Serene (simple) - A PoC lisp to collect data on Serenes concepts
+ * Copyright (C) 2019-2020 Sameer Rahmani <lxsameer@gnu.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA  02110-1301, USA.
+ */
+package serene.simple.builtin;
+
+import java.util.List;
+
+import serene.simple.IScope;
+import serene.simple.SNumber;
+import serene.simple.SereneException;
+
+
+public class EqFn extends AFn {
+  public String fnName() {
+    return "=";
+  };
+
+  public Object eval(IScope scope) throws SereneException{
+    List<Object> args = this.arguments();
+
+    if (args.size() == 0) {
+      throw new SereneException(
+        "ArityError: You need 1 or more parameters for this functions.");
+    }
+
+    if (args.size() == 1) {
+      return true;
+    }
+
+    Object result = args.get(0);
+
+    for (Object x : args.subList(1, args.size())) {
+      if (x == null) {
+        result = (Object) (result == null);
+      }
+      else {
+        result = result.equals(x);
+      }
+    }
+
+    return (boolean) result;
+  }
+}