* arith.c (plus, minus): Better wording in error messages.

* eval.c (dwim_loc): Assignments to string indices and ranges
supported. New arguments for this purpose.
(op_modplace): Use new dwim_loc interface for returned value.
(op_dwim): Support assignment to string ranges.
(eval_init): replace_str registered.

* lib.c (string_extend): If the argument is a number, let it
specify the amount by which to extend the string.
(replace_str): New function.

* lib.h (replace_str): Declared.

* txr.1: Updated.

* txr.vim: Updated.

1 files changed, 2 insertions, 2 deletions

diff --git a/arith.c b/arith.c
index d736e925..68f8988f 100644
--- a/arith.c
+++ b/arith.c
@@ -348,7 +348,7 @@ val plus(val anum, val bnum)
   uw_throwf(error_s, lit("plus: invalid operands ~s ~s"), anum, bnum, nao);
 char_range:
   uw_throwf(numeric_error_s, 
-            lit("plus: sum of ~s ~s is out of character range"),
+            lit("plus: sum of ~s and ~s is out of character range"),
             anum, bnum, nao);
 }
 
@@ -429,7 +429,7 @@ val minus(val anum, val bnum)
 
       if (sum < 0 || sum > 0x10FFFF)
         uw_throwf(numeric_error_s, 
-                  lit("minus: sum of ~s ~s is out of character range"),
+                  lit("minus: difference of ~s and ~s is out of character range"),
                   anum, bnum, nao);
       return chr(sum);
     }