Minor changes

2 files changed, 11 insertions, 8 deletions

diff --git a/scheme/aps/lang.sls b/scheme/aps/lang.sls
index f2da11e..1693259 100644
--- a/scheme/aps/lang.sls
+++ b/scheme/aps/lang.sls
@@ -9,7 +9,8 @@
     (sub (: let-form e)
          #'e)
     (sub (: let-form e1 e2)
-         (syntax-violation ': "Odd number of arguments" #'(let-form e1 e2)))
+         (syntax-violation ': "Odd number of arguments"
+          (syntax->datum #'(let-form e1 e2))))
     (sub (: let-form patt value rest ... expr)
          #'(let-form ((patt value)) (: let-form rest ... expr))
          (identifier? #'let-form)
diff --git a/scheme/aps/string-utils.sls b/scheme/aps/string-utils.sls
index 8e8aaf1..0d6b8c0 100644
--- a/scheme/aps/string-utils.sls
+++ b/scheme/aps/string-utils.sls
@@ -1,21 +1,23 @@
 (library (aps string-utils)
 (export string-split)
-(import (rnrs))
+(import (rnrs) (aps compat))
 
+;;STRING-SPLIT
+;; adapted from http://schemecookbook.org/Cookbook/StringSplit
+;; to match Python behaviour
 (define (string-split str ch)
   (define len (string-length str))
   (define (split a b)
+    ;(printf "~a: ~a ~a\n" str a b)
     (cond
      ((>= b len)
-      (if (= a b) '()
+      (if (= a b) '("")
           (list (substring str a b))))
      ((char=? ch (string-ref str b))
-      (if (= a b) (split (+ 1 a) (+ 1 b))
+      (if (= a b) (let ((res (split (+ 1 a) (+ 1 b))))
+                    (if (= 0 a) (cons "" res) res))
           (cons (substring str a b) (split b b))))
      (else (split a (+ 1 b)))))
   (split 0 0))
+;;END
 )
-
-;(display (string-split "a.b" #\.))
-;(display (string-split ".b" #\.))
-;(display (string-split "a." #\.))