number->string with bases up to 36

[Diego A. Mundo via Chicken-hackers]

Hi all,

I noticed number->string still only works with bases up to 16, while 
string->number works up to base 36. I have attached a trivial patch on top of 
master that appears to do the thing.

I'm not sure if this might have adverse effects elsewhere, but at least make 
check passes.

Thanks,
Diego
From 0133f739d5b0e0a3df71b797fdf5dbcdf81033e9 Mon Sep 17 00:00:00 2001
From: "Diego A. Mundo" <dieg...@pm.me>
Date: Thu, 15 Jan 2026 01:21:05 -0500
Subject: [PATCH] Make number->string work with bases up to 36

---
 runtime.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/runtime.c b/runtime.c
index 084c7a4f..7f038935 100644
--- a/runtime.c
+++ b/runtime.c
@@ -11135,7 +11135,7 @@ static C_regparm double decode_flonum_literal(C_char *str)
 
 static char *to_n_nary(C_uword num, C_uword base, int negp, int as_flonum)
 {
-  static char *digits = "0123456789abcdef";
+  static char *digits = "0123456789abcdefghijklmnopqrstuvwxyz";
   char *p;
   C_uword shift = C_ilen(base) - 1;
   int mask = (1 << shift) - 1;
@@ -11203,7 +11203,7 @@ void C_ccall C_fixnum_to_string(C_word c, C_word *av)
     radix = ((c == 3) ? 10 : C_unfix(av[ 3 ])),
     neg = ((num & C_INT_SIGN_BIT) ? 1 : 0);
 
-  if (radix < 2 || radix > 16) {
+  if (radix < 2 || radix > 36) {
     barf(C_BAD_ARGUMENT_TYPE_BAD_BASE_ERROR, "number->string", C_fix(radix));
   }
 
@@ -11287,7 +11287,7 @@ void C_ccall C_integer_to_string(C_word c, C_word *av)
     int len, radix_shift;
     size_t nbits;
 
-    if ((radix < 2) || (radix > 16)) {
+    if ((radix < 2) || (radix > 36)) {
       barf(C_BAD_ARGUMENT_TYPE_BAD_BASE_ERROR, "number->string", C_fix(radix));
     }
 
@@ -11327,7 +11327,7 @@ void C_ccall C_integer_to_string(C_word c, C_word *av)
 
 static void bignum_to_str_2(C_word c, C_word *av)
 {
-  static char *characters = "0123456789abcdef";
+  static char *characters = "0123456789abcdefghijklmnopqrstuvwxyz";
   C_word
     self = av[ 0 ],
     string = av[ 1 ],
-- 
2.52.0