From 70ff9b7e1b9e7a666eee7f509ecff846144eeeea Mon Sep 17 00:00:00 2001
From: Nat Quayle Nelson <natquaylenelson@gmail.com>
Date: Wed, 25 Nov 2020 11:43:04 -0700
Subject: [PATCH] add not, with a reader macro

---
 src/kiss/Reader.hx                | 2 ++
 src/kiss/SpecialForms.hx          | 8 ++++++++
 src/test/cases/BasicTestCase.hx   | 5 +++++
 src/test/cases/BasicTestCase.kiss | 5 ++++-
 4 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/src/kiss/Reader.hx b/src/kiss/Reader.hx
index fc5a6bd2..1e6cfd8e 100644
--- a/src/kiss/Reader.hx
+++ b/src/kiss/Reader.hx
@@ -48,6 +48,8 @@ class Reader {
 
         readTable["&"] = (stream) -> MetaExp(nextToken(stream, "a meta symbol like mut, optional, rest"));
 
+        readTable["!"] = (stream:Stream) -> CallExp(Symbol("not").withPos(stream.position()), [assertRead(stream, readTable)]);
+
         // Because macro keys are sorted by length and peekChars(0) returns "", this will be used as the default reader macro:
         readTable[""] = (stream) -> Symbol(nextToken(stream, "a symbol name"));
 
diff --git a/src/kiss/SpecialForms.hx b/src/kiss/SpecialForms.hx
index 60722c9b..bc97ce9d 100644
--- a/src/kiss/SpecialForms.hx
+++ b/src/kiss/SpecialForms.hx
@@ -195,6 +195,14 @@ class SpecialForms {
                 $elseExp;
         };
 
+        map["not"] = (args:Array<ReaderExp>, convert:ExprConversion) -> {
+            if (args.length != 1)
+                throw '(not... ) only takes one argument, not $args';
+            var condition = convert(args[0]);
+            var truthyExp = macro Prelude.truthy($condition);
+            macro !$truthyExp;
+        };
+
         return map;
     }
 
diff --git a/src/test/cases/BasicTestCase.hx b/src/test/cases/BasicTestCase.hx
index 725886e3..b8b7d1fc 100644
--- a/src/test/cases/BasicTestCase.hx
+++ b/src/test/cases/BasicTestCase.hx
@@ -173,4 +173,9 @@ class BasicTestCase extends Test {
     function testOr() {
         Assert.equals(5, BasicTestCase.myOr1);
     }
+
+    function testNot() {
+        Assert.equals(false, BasicTestCase.myNot1);
+        Assert.equals(false, BasicTestCase.myNot2);
+    }
 }
diff --git a/src/test/cases/BasicTestCase.kiss b/src/test/cases/BasicTestCase.kiss
index d3a870b2..f0220b7b 100644
--- a/src/test/cases/BasicTestCase.kiss
+++ b/src/test/cases/BasicTestCase.kiss
@@ -133,4 +133,7 @@
 (defun mySetLocal []
     (deflocal loc &mut "one thing")
     (set loc "another thing")
-    loc)
\ No newline at end of file
+    loc)
+
+(defvar myNot1 (not 5))
+(defvar myNot2 !5)
\ No newline at end of file