Add some builtin functions and some examples.

lib/fizzbuzz.dst

@@ -0,0 +1,13 @@
+# A simple fizz buzz example
+
+(defn fizzbuzz
+ "Prints the fizzbuzz problem."
+ []
+ (for [i 1 101]
+  (let [fizz (zero? (% i 3))
+        buzz (zero? (% i 5))]
+    (print (cond
+        (and fizz buzz) "fizzbuzz"
+        fizz "fizz"
+        buzz "buzz"
+        i)))))

lib/hello.dst

@@ -0,0 +1,3 @@
+# Prints hello
+
+(print "hello, world!")

lib/pp.dst

@@ -1,31 +1,7 @@
-(def a (fn [] 2))
-#
-# Copyright (c) 2017 Calvin Rose
-#
-# Permission is hereby granted, free of charge, to any person obtaining a copy
-# of this software and associated documentation files (the "Software"), to
-# deal in the Software without restriction, including without limitation the
-# rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
-# sell copies of the Software, and to permit persons to whom the Software is
-# furnished to do so, subject to the following conditions:
-#
-# The above copyright notice and this permission notice shall be included in
-# all copies or substantial portions of the Software.
-#
-# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
-# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
-# IN THE SOFTWARE.
-#
+# Implements a simple pretty printer. Offers similar functionality
+# as the describe function.
 
-# Define a simple pretty printer
-
-(def pp (do
-
-(defn pp-seq [pp seen buf a start end]
+(defn- pp-seq [pp seen buf a start end]
  (if (get seen a)
   (buffer-push-string buf "<cycle>")
   (do
@@ -35,11 +11,10 @@
    (for [i 0 len]
     (when (not= i 0) (buffer-push-string buf " "))
     (pp seen buf (get a i)))
-   (buffer-push-string buf end)
-  ))
+   (buffer-push-string buf end)))
  buf)
-  
-(defn pp-dict [pp seen buf a start end]
+
+(defn- pp-dict [pp seen buf a start end]
  (if (get seen a)
   (buffer-push-string buf "<cycle>")
   (do
@@ -52,26 +27,26 @@
     (buffer-push-string buf " ")
     (pp seen buf v)
     (varset! k (next a k))
-    (when k (buffer-push-string buf " "))
-   )
-   (buffer-push-string buf end)
-  ))
+    (when k (buffer-push-string buf " ")))
+   (buffer-push-string buf end)))
  buf)
 
-(def _printers {
+(def printers :private {
  :array  (fn [pp seen buf x] (pp-seq pp seen buf x "[" "]"))
  :tuple  (fn [pp seen buf x] (pp-seq pp seen buf x "(" ")"))
  :table  (fn [pp seen buf x] (pp-dict pp seen buf x "@{" "}"))
  :struct (fn [pp seen buf x] (pp-dict pp seen buf x "{" "}"))
 })
 
-(defn _default_printer [pp seen buf x] 
+(defn- default_printer [pp seen buf x] 
  (buffer-push-string buf (string x)) 
  buf)
 
-(defn pp1 [seen buf x]
-  (def pmaybe (get _printers (type x)))
-  (def p (if pmaybe pmaybe _default_printer))
+(defn- pp1 [seen buf x]
+  (def pmaybe (get printers (type x)))
+  (def p (if pmaybe pmaybe default_printer))
   (p pp1 seen buf x))
 
-(fn [x] (print (pp1 @{} @"" x)))))
+(defn pp 
+ "Pretty print a value x."
+ [x] (print (pp1 @{} @"" x)))

lib/primes.dst

@@ -0,0 +1,14 @@
+# Return an array of primes. This is a trivial and extremely naive algorithm.
+
+(defn primes
+ "Returns a list of prime numbers less than n."
+ [n]
+ (def list [])
+ (for [i 2 n]
+  (var isprime? true)
+  (def len (length list))
+  (for [j 0 len]
+   (def trial (get list j))
+   (if (zero? (% i trial)) (varset! isprime? false)))
+  (if isprime? (array-push list i)))
+ list)