From adc9664c699104aba2e8b16e3a06ca08c12296a5 Mon Sep 17 00:00:00 2001
From: Pekka Laiho <pekka.i.laiho@gmail.com>
Date: Wed, 3 Jun 2020 14:37:04 +0700
Subject: [PATCH] add 3 new functions for collections

---
 src/Evaller.php         |  2 ++
 src/Lib/Collections.php | 24 ++++++++++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/src/Evaller.php b/src/Evaller.php
index fd71c80..49e7b7e 100644
--- a/src/Evaller.php
+++ b/src/Evaller.php
@@ -66,6 +66,8 @@ class Evaller
                 }
 
                 return $value;
+            } elseif ($ast->get(0)->getName() == 'env') {
+                return $env;
             } elseif ($ast->get(0)->getName() == 'fn') {
                 if ($ast->count() != 3) {
                     throw new MadLispException("fn requires exactly 2 arguments");
diff --git a/src/Lib/Collections.php b/src/Lib/Collections.php
index 1f1d105..0f956b8 100644
--- a/src/Lib/Collections.php
+++ b/src/Lib/Collections.php
@@ -104,6 +104,10 @@ class Collections implements ILib
             }
         ));
 
+        $env->set('reverse', new CoreFunc('reverse', 'Create new sequence with reversed order.', 1, 1,
+            fn (Seq $a) => $a::new(array_reverse($a->getData()))
+        ));
+
         // Hash map functions
 
         $env->set('key?', new CoreFunc('key?', 'Return true if first argument (hash-map) contains the second argument as key.', 2, 2,
@@ -133,5 +137,25 @@ class Collections implements ILib
         $env->set('values', new CoreFunc('values', 'Return the values of a hash-map as a list.', 1, 1,
             fn (Hash $a) => new MList(array_values($a->getData()))
         ));
+
+        $env->set('zip', new CoreFunc('zip', 'Create new hash-map using first argument as keys and second argument as values.', 2, 2,
+            function (Seq $keys, Seq $vals) {
+                if ($keys->count() != $vals->count()) {
+                    throw new MadLispException('zip requires equal number of keys and values');
+                }
+
+                return new Hash(array_combine($keys->getData(), $vals->getData()));
+            }
+        ));
+
+        // Sorting
+
+        $env->set('sort', new CoreFunc('sort', 'Sort the sequence in ascending order.', 1, 1,
+            function (Seq $a) {
+                $data = $a->getData();
+                sort($data);
+                return $a::new($data);
+            }
+        ));
     }
 }