collectWhileLet

src/kiss/Macros.hx

@@ -839,6 +839,22 @@ class Macros {
             ]);
         };
 
+        k.doc("collectWhileLet", 2, null, "(collectWhileLet [<bindings...>] <body...>)");
+        macros["collectWhileLet"] = (wholeExp:ReaderExp, exps:Array<ReaderExp>, k:KissState) -> {
+            var b = wholeExp.expBuilder();
+            var results = b.symbol();
+            var nextExp = b.symbol();
+            var body = b.begin(exps.slice(1));
+            return b.let([results, b.list([])], [
+                b.callSymbol("whileLet", [
+                    exps[0],
+                    b.let([nextExp, body],
+                        [b.callField("push", results, [nextExp])])
+                ]),
+                results
+            ]);
+        };
+
         k.doc("withTempSet", 2, null, "(withTempSet [<bindings...>] <body...>)");
         macros["withTempSet"] = (wholeExp:ReaderExp, exps:Array<ReaderExp>, k:KissState) -> {
             var b = wholeExp.expBuilder();

src/test/cases/BasicTestCase.kiss

@@ -679,7 +679,14 @@ From:[(assert false (+ \"false \" \"should \" \"have \" \"been \" \"true\"))]" m
             stream (Stream.fromString "a\nb\nc")]
         (whileLet [(Some line) (stream.takeLine)]
             (Assert.equals (nth lines idx) line)
-            (+= idx 1))))
+            (+= idx 1)))
+    (let [lines ["a" "b" "c"]
+            options [(Some "a") (Some "b") (Some "c") None]
+            collected
+                (collectWhileLet [(Some line) (options.shift)]
+                    line)]
+        (doFor i (range collected.length)
+            (Assert.equals (nth lines i) (nth collected i)))))
 
 (function _testTrace []
     (Assert.equals 5 (trace 5 "num"))