From 3f9bc2dbb00102b17488afaa353083e36c230940 Mon Sep 17 00:00:00 2001
From: Ian Price <ianprice90@googlemail.com>
Date: Mon, 14 Aug 2017 16:26:39 +0100
Subject: [PATCH] Implement basic `equal?' implementation

* module/language/js-il/runtime.js (equal?): Remove primitive.
  Implement as builtin procedure. This version Only handles pairs.
---
 module/language/js-il/runtime.js | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/module/language/js-il/runtime.js b/module/language/js-il/runtime.js
index c9328a675..34dd3a66a 100644
--- a/module/language/js-il/runtime.js
+++ b/module/language/js-il/runtime.js
@@ -496,8 +496,6 @@ scheme.primitives["eqv?"] = function(x, y) {
     return coerce_bool(x === y);
 };
 
-scheme.primitives["equal?"] = not_implemented_yet;
-
 // Fluids
 scheme.Fluid = function (x) {
     this.value = x;
@@ -761,6 +759,24 @@ def_guile0("append", function (self, cont, l1, l2) {
     return cont(l);
 });
 
+function scm_equal(x,y) {
+    if (x instanceof scheme.Pair) {
+        if (y instanceof scheme.Pair) {
+            return (scm_equal(x.car,y.car) && scm_equal(x.cdr,y.cdr));
+        } else {
+            return false;
+        }
+    } else if (y instanceof scheme.Pair) {
+        return false;
+    } else {
+        return (x === y);
+    }
+}
+
+def_guile0("equal?", function (self, cont, x, y) {
+    return cont(coerce_bool(scm_equal(x,y)));
+});
+
 def_guile0("memq", function (self, cont, val, args) {
     return cont(scheme.FALSE);
 });