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Updare examples. Delete ugly iterator example.

This commit is contained in:
Calvin Rose 2018-11-26 22:09:12 -05:00
parent f860b950fc
commit ea4465f58e
5 changed files with 12 additions and 125 deletions

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@ -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)))

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@ -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)
})

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@ -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))

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@ -18,7 +18,6 @@
'[[3]
[7 10]
[4 3 7]
[8 9 1 3]
])
[8 9 1 3]])
(print (maxpath triangle))

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@ -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))))))