klisp

commit ffea32ebb7d94db893c87aa9eb1abf8d34e340cd
parent eea32057ab434149cd47c50f99cc898c1ac7f586
Author: Andres Navarro <canavarro82@gmail.com>
Date:   Thu, 27 Oct 2011 15:00:17 -0300

Bugfix: substring now follows the mutability of the source. Revised some test cases.

Diffstat:
M
src/kgstrings.c
 | 
6
++++--
M
src/tests/strings.k
 | 
11
++++++++++-

2 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/src/kgstrings.c b/src/kgstrings.c
@@ -239,7 +239,7 @@ bool kstring_ci_gep(TValue str1, TValue str2)
 }
 
 /* 13.2.5? substring */
-/* TEMP: at least for now this always returns mutable strings */
+/* Note: This will return an mutable string iff the source string is mutable */
 void substring(klisp_State *K, TValue *xparams, TValue ptree, TValue denv)
 {
     UNUSED(xparams);
@@ -276,8 +276,10 @@ void substring(klisp_State *K, TValue *xparams, TValue ptree, TValue denv)
     /* the if isn't strictly necessary but it's clearer this way */
     if (size == 0) {
 	new_str = K->empty_string;
-    } else {
+    } else if (kstring_mutablep(str)) {
 	new_str = kstring_new_bs(K, kstring_buf(str)+start, size);
+    } else {
+	new_str = kstring_new_bs_imm(K, kstring_buf(str)+start, size);
     }
     kapply_cc(K, new_str);
 }
diff --git a/src/tests/strings.k b/src/tests/strings.k
@@ -129,10 +129,19 @@
 ($check-error (substring "abcdef" 3 10))
 ($check-error (substring "abcdef" 4 2))
 
-($check-not-predicate
+
+;; immutable strings are eq? iff string=?
+;; Andres Navarro
+($check-predicate
   ($let* ((p "abc") (q (substring p 0 3)))
     (eq? p q)))
 
+;; string-copy always generate mutable strings
+;; Andres Navarro
+($check-not-predicate
+ ($let* ((p (string-copy "abc")) (q (substring p 0 3)))
+   (eq? p q)))
+
 ($check-predicate (immutable-string? (substring "abc" 0 0)))
 ($check-predicate (immutable-string? (substring "abc" 0 1)))