Re: [PATCHES] concat, read, substr, added 'ord' operator, and aSURPRISE

[Alex Gough]

On Sat, 10 Nov 2001, Jeff wrote:

> string.pasm patches the operators mentioned
> The other file, 'parrot.pasm', is a miniature Parrot compiler, written
> in Parrot.
> 
> The patches in the string.diff file are required to make this work.

ook, cool, but string_length returns an INTVAL, not an int.

Alex Gough

diff -ru parrot_orig/string.c parrot/string.c
--- parrot_orig/string.c        Wed Oct 31 17:51:31 2001
+++ parrot/string.c     Sat Nov 10 18:16:27 2001
@@ -83,6 +83,33 @@
     return s->strlen;
 }
 
+/*=for api string string_ord
+ * return the length of the string
+ */
+INTVAL
+string_ord(STRING* s, INTVAL index) {
+    if(s==NULL) {
+        INTERNAL_EXCEPTION(ORD_OUT_OF_STRING,
+                           "Cannot get character of empty string");
+    }
+    else {
+        INTVAL len = string_length(s);
+        if(index < 0) {
+            INTERNAL_EXCEPTION(ORD_OUT_OF_STRING,
+                               "Cannot get character at negative index");
+        }
+        else if(index > (len - 1)) {
+            INTERNAL_EXCEPTION(ORD_OUT_OF_STRING,
+                               "Cannot get character past end of string");
+        }
+        else {
+            char *buf = s->bufstart;
+            return buf[index];
+        }
+    }
+    return -1;
+}
+
 /*=for api string string_copy
  * create a copy of the argument passed in
  */
@@ -175,13 +202,19 @@
  */
 STRING*
 string_concat(struct Parrot_Interp *interpreter, STRING* a, STRING* b, INTVAL flags) {
-    if (a->type != b->type || a->encoding != b->encoding) {
-        b = string_transcode(interpreter, b, a->encoding, a->type, NULL);
+    if(a != NULL) {
+        if (a->type != b->type || a->encoding != b->encoding) {
+            b = string_transcode(interpreter, b, a->encoding, a->type, NULL);
+        }
+        string_grow(a, a->strlen + b->strlen);
+        mem_sys_memcopy((void*)((ptrcast_t)a->bufstart + a->bufused),b->bufstart, 
+b->bufused);
+        a->strlen = a->strlen + b->strlen;
+        a->bufused = a->bufused + b->bufused;
+    }
+    else {
+      return string_make(interpreter,
+                         b->bufstart,b->buflen,b->encoding,flags,b->type);
     }
-    string_grow(a, a->strlen + b->strlen);
-    mem_sys_memcopy((void*)((ptrcast_t)a->bufstart + a->bufused), 
b->bufstart,b->bufused);
-    a->strlen = a->strlen + b->strlen;
-    a->bufused = a->bufused + b->bufused;
     return a;
 }