refactored ebus code

1 files changed, 53 insertions, 0 deletions

diff --git a/ebus-racket/3rdparty/bzlib/parseq/util.ss b/ebus-racket/3rdparty/bzlib/parseq/util.ss
new file mode 100644
index 0000000..822ce3c
--- /dev/null
+++ b/ebus-racket/3rdparty/bzlib/parseq/util.ss
@@ -0,0 +1,53 @@
+#lang scheme/base
+;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; PARSEQ.PLT 
+;; A Parser Combinator library.
+;; 
+;; Bonzai Lab, LLC.  All rights reserved.
+;; 
+;; Licensed under LGPL.
+;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; util.ss - an utility module... the code might be moved out of here... 
+;; yc 12/31/2009 - first version 
+
+(require mzlib/etc
+         )
+
+;; the-number
+;; makes a function that returns a particular number no matter what 
+;; args are passed in
+(define (the-number n)
+  (lambda args n))
+
+;; bits->byte
+;; convert a list of bits into its corresponding byte (or integer...) 
+;; note the byte can be greater than 255
+(define (bits->byte bits)
+  (define (->i bit)
+    (case bit
+      ((0 #f) 0)
+      ((1 #t) 1)))
+  (apply + 
+         (map (lambda (bit exponent)
+                (* (->i bit) (expt 2 exponent)))
+              bits
+              (reverse (build-list (length bits) identity)))))
+
+;; byte->bits 
+;; the reverse of converting byte to bits... 
+(define (byte->bits b) 
+  (define (helper q acc) 
+    (cond ((= 0 q) acc)
+          (else
+           (let-values (((q r)
+                         (quotient/remainder q 2)))
+             (helper q (cons r acc))))))
+  (helper b '()))
+
+;; string-bytes/utf-8-length 
+;; return the bytes length for a string (instead of character length) 
+(define (string-bytes/utf-8-length s)
+  (bytes-length (string->bytes/utf-8 s)))
+
+(provide (all-defined-out)) 
+