From ea4465f58e96b8173bf53a573e079ddc662dc89d Mon Sep 17 00:00:00 2001
From: Calvin Rose <calsrose@gmail.com>
Date: Mon, 26 Nov 2018 22:09:12 -0500
Subject: [PATCH] Updare examples. Delete ugly iterator example.

---
 examples/fizzbuzz.janet    |  19 +++----
 examples/iterators.janet   | 107 -------------------------------------
 examples/life.janet        |   7 +--
 examples/maxtriangle.janet |   3 +-
 src/core/core.janet        |   1 +
 5 files changed, 12 insertions(+), 125 deletions(-)
 delete mode 100644 examples/iterators.janet

diff --git a/examples/fizzbuzz.janet b/examples/fizzbuzz.janet
index e331b863..6d4cddac 100644
--- a/examples/fizzbuzz.janet
+++ b/examples/fizzbuzz.janet
@@ -1,13 +1,10 @@
 # A simple fizz buzz example
 
-(defn fizzbuzz
-  "Prints the fizzbuzz problem."
-  []
-  (loop [i :range [1 101]]
-    (let [fizz (zero? (% i 3))
-          buzz (zero? (% i 5))]
-      (print (cond
-               (and fizz buzz) "fizzbuzz"
-               fizz "fizz"
-               buzz "buzz"
-               i)))))
+(loop [i :range [1 101]
+       :let [fizz (zero? (% i 3))
+             buzz (zero? (% i 5))]]
+  (print (cond
+           (and fizz buzz) "fizzbuzz"
+           fizz "fizz"
+           buzz "buzz"
+           i)))
diff --git a/examples/iterators.janet b/examples/iterators.janet
deleted file mode 100644
index 2162c67d..00000000
--- a/examples/iterators.janet
+++ /dev/null
@@ -1,107 +0,0 @@
-###
-###
-### Iterators
-###
-###
-
-(def iter (do
-            (defn array-iter [x]
-              (def len (length x))
-              (var i 0)
-              {:more (fn [] (< i len))
-               :next (fn []
-                       (def ret (get x i))
-                       (:= i (+ i 1))
-                       ret)})
-            (def iters {
-                        :array array-iter
-                        :tuple array-iter
-                        :struct identity})
-            (fn [x]
-              (def makei (get iters (type x)))
-              (if makei (makei x) (error "expected sequence")))))
-
-(defn range2 [bottom top]
-  (var i bottom)
-  {
-   :more (fn [] (< i top))
-   :next (fn []
-           (def ret i)
-           (:= i (+ i 1))
-           ret)
-   })
-
-(defn range [top] (range2 0 top))
-
-(defn doiter [itr]
-  (def {:more more :next next} (iter itr))
-  (while (more) (next)))
-
-(defn foreach [itr f]
-  (def {:more more :next next} (iter itr))
-  (while (more) (f (next))))
-
-(defn iter2array [itr]
-  (def {:more more :next next} (iter itr))
-  (def a @[])
-  (while (more) (array.push a (next)))
-  a)
-
-(defn map [f itr]
-  (def {:more more :next next} (iter itr))
-  {:more more :next (fn [] (f (next)))})
-
-(defn reduce [f start itr]
-  (def itr (iter itr))
-  (def {:more more :next next} itr)
-  (if (more)
-    (reduce f (f start (next)) itr)
-    start))
-
-(defn filter [pred itr]
-  (def itr (iter itr))
-  (def {:more more :next next} itr)
-  (var alive true)
-  (var temp nil)
-  (var isnew true)
-  (defn nextgood []
-    (if alive
-      (if (more)
-        (do
-          (def n (next))
-          (if (pred n) n (nextgood)))
-        (:= alive false))))
-  (defn nnext [] (def ret temp) (:= temp (nextgood)) ret)
-  (defn nmore [] (when isnew (:= isnew false) (nnext)) alive)
-  {:more nmore :next nnext})
-
-(defn pairs [x]
-  (var lastkey (next x nil))
-  {
-   :more (fn [] lastkey)
-   :next (fn []
-           (def ret (tuple lastkey (get x lastkey)))
-           (:= lastkey (next x lastkey))
-           ret)
-   })
-
-(defn keys [x]
-  (var lastkey (next x nil))
-  {
-   :more (fn [] lastkey)
-   :next (fn []
-           (def ret lastkey)
-           (:= lastkey (next x lastkey))
-           ret)
-   })
-
-(defn values [x]
-  (var lastkey (next x nil))
-  {
-   :more (fn [] lastkey)
-   :next (fn []
-           (def ret (get x lastkey))
-           (:= lastkey (next x lastkey))
-           ret)
-   })
-
diff --git a/examples/life.janet b/examples/life.janet
index 12fb3c0f..74a376f1 100644
--- a/examples/life.janet
+++ b/examples/life.janet
@@ -25,11 +25,8 @@
   [state x1 y1 x2 y2]
   (def cellset @{})
   (loop [cell :in state] (put cellset cell true))
-  (loop [:before (print "+" (string.repeat "--" (inc (- y2 y1))) "+")
-         :after (print "+" (string.repeat "--" (inc (- y2 y1))) "+")
-         x :range [x1 (+ 1 x2)]
-         :before (file.write stdout "|")
-         :after (file.write stdout "|\n")
+  (loop [x :range [x1 (+ 1 x2)]
+         :after (print)
          y :range [y1 (+ 1 y2)]]
     (file.write stdout (if (get cellset (tuple x y)) "X " ". ")))
   (print))
diff --git a/examples/maxtriangle.janet b/examples/maxtriangle.janet
index a2f77125..41425841 100644
--- a/examples/maxtriangle.janet
+++ b/examples/maxtriangle.janet
@@ -18,7 +18,6 @@
   '[[3]
     [7 10]
     [4 3 7]
-    [8 9 1 3]
-    ])
+    [8 9 1 3]])
 
 (print (maxpath triangle))
diff --git a/src/core/core.janet b/src/core/core.janet
index 297d471e..6f6e1d18 100644
--- a/src/core/core.janet
+++ b/src/core/core.janet
@@ -416,6 +416,7 @@
   "Create a generator expression using the loop syntax. Returns a fiber
   that yields all values inside the loop in order. See loop for details."
   [head & body]
+  # `(fiber.new (fn [&] (loop ,head (yield (do ,@body)))))
   (tuple fiber.new
          (tuple 'fn '[&]
                 (tuple 'loop head (tuple yield (tuple.prepend body 'do))))))