From c52e74c2351c3f5f430cc54ea3dc642702b253e7 Mon Sep 17 00:00:00 2001
From: Nat Quayle Nelson <natquaylenelson@gmail.com>
Date: Mon, 23 May 2022 00:29:01 +0000
Subject: [PATCH] whileLet

---
 src/kiss/Macros.hx                | 12 ++++++++++++
 src/test/cases/BasicTestCase.hx   |  5 +++++
 src/test/cases/BasicTestCase.kiss | 10 +++++++++-
 3 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/src/kiss/Macros.hx b/src/kiss/Macros.hx
index 63b0366..e8a38b2 100644
--- a/src/kiss/Macros.hx
+++ b/src/kiss/Macros.hx
@@ -747,6 +747,18 @@ class Macros {
         }
 
         macros["awaitLet"] = awaitLet;
+        
+        macros["whileLet"] = (wholeExp:ReaderExp, exps:Array<ReaderExp>, k:KissState) -> {
+            wholeExp.checkNumArgs(2, null, "(whileLet [<bindings...>] <body...>)");
+            var b = wholeExp.expBuilder();
+            return b.callSymbol("loop", [
+                b.callSymbol("ifLet", [
+                    exps[0],
+                        b.begin(exps.slice(1)),
+                    b.callSymbol("break", [])
+                ])
+            ]);
+        };
 
         // TODO test defNew
         macros["defnew"] = (wholeExp:ReaderExp, exps:Array<ReaderExp>, k:KissState) -> {
diff --git a/src/test/cases/BasicTestCase.hx b/src/test/cases/BasicTestCase.hx
index f267b76..abd2ad3 100644
--- a/src/test/cases/BasicTestCase.hx
+++ b/src/test/cases/BasicTestCase.hx
@@ -4,6 +4,7 @@ import utest.Test;
 import utest.Assert;
 import kiss.Prelude;
 import kiss.List;
+import kiss.Stream;
 import haxe.ds.Option;
 
 using StringTools;
@@ -341,6 +342,10 @@ class BasicTestCase extends Test {
     function testIntersect() {
         _testIntersect();
     }
+
+    function testWhileLet() {
+        _testWhileLet();
+    }
 }
 
 class BasicObject {
diff --git a/src/test/cases/BasicTestCase.kiss b/src/test/cases/BasicTestCase.kiss
index 455d7a2..cbfb3d4 100644
--- a/src/test/cases/BasicTestCase.kiss
+++ b/src/test/cases/BasicTestCase.kiss
@@ -628,4 +628,12 @@
         (assert (contains intersection3d "cy1"))
         (assert (contains intersection3d "cy3"))
         )
-    (Assert.pass))
\ No newline at end of file
+    (Assert.pass))
+
+(function _testWhileLet []
+    (let [&mut idx 0
+            lines ["a" "b" "c"]
+            stream (Stream.fromString "a\nb\nc")]
+        (whileLet [(Some line) (stream.takeLine)]
+            (Assert.equals (nth lines idx) line)
+            (+= idx 1))))
\ No newline at end of file