[PATCH CVS] Strchr(77), Strchr([79,75])

[Ilya Zakharevich <ilya@Math.Berkeley.EDU>]

This patch allows one to invert Vecsmall("OK").

Enjoy,
Ilya

P.S.  Should not we replace t_STR to allow lgef() - which would specify the
      length of the string.  This would allow to have strings with
      embedded \0 as well...  I grepped for t_STR, and think the patch
      would be very short.

--- ./src/language/anal.h-pre	Sat Feb 22 23:58:44 2003
+++ ./src/language/anal.h	Sat Mar  1 01:49:02 2003
@@ -262,6 +262,7 @@ void writetex(const char *s, GEN g);
 GEN Str(GEN g);
 GEN Strexpand(GEN g);
 GEN Strtex(GEN g);
+GEN Str_char(GEN g);
 
 /* for output */
 typedef struct {
--- ./src/language/es.c-pre	Sat Mar  1 01:48:40 2003
+++ ./src/language/es.c	Sat Mar  1 01:48:10 2003
@@ -725,6 +725,33 @@ Strexpand(GEN g) {
   GEN z = STRtoGENstr(t);
   free(t); free(s); return z;
 }
+GEN
+Str_char(GEN g) {
+  long n;
+  unsigned char buf[2];
+
+  if (is_vec_t(typ(g))) {
+    long l = lg(g), i;
+    long len = (l+BYTES_IN_LONG-1) >> TWOPOTBYTES_IN_LONG;
+    GEN x = cgetg(len+1, t_STR);
+    char *s = GSTR(x);
+    
+    for (i=1; i<l; i++) {
+      n = itos((GEN)g[i]);
+      if (n <= 0 || n > 255)
+        err(talker, "Out of range in integer -> character conversion");
+      *s++ = n;
+    }
+    *s = 0;
+    return x;
+  }
+  n = itos(g);
+  if (n <= 0 || n > 255)
+    err(talker, "Out of range in integer -> character conversion");
+  buf[0] = n;				/* UTF8 ? */
+  buf[1] = 0;
+  return STRtoGENstr(buf);
+}
 
 /********************************************************************/
 /**                                                                **/
--- ./src/language/helpmsg.c-pre	Sun Jan 12 16:32:58 2003
+++ ./src/language/helpmsg.c	Sat Mar  1 01:52:54 2003
@@ -27,6 +27,7 @@ char *helpmessages_basic[]={
   "Ser(x,{v=x}): convert x (usually a vector) into a power series with variable v, starting with the constant coefficient",
   "Set({x=[]}): convert x into a set, i.e. a row vector with strictly increasing coefficients. Empty set if x is omitted",
   "Str({str}*): concatenates its (string) argument into a single string",
+  "Strchr(x): converts x to string, translating each integer into a characters",
   "Strexpand({str}*): concatenates its (string) argument into a single string, performing tilde expansion",
   "Strtex({str}*): translates its (string) arguments to TeX format and returns the resulting string",
   "Vec({x=[]}): transforms the object x into a vector. Used mainly if x is a polynomial or a power series. Empty vector if x is omitted",
--- ./src/language/init.c-pre	Sat Feb 22 19:58:36 2003
+++ ./src/language/init.c	Sat Mar  1 01:50:36 2003
@@ -2018,6 +2018,7 @@ entree functions_basic[]={
 {"Ser",14,(void*)gtoser,2,"GDn"},
 {"Set",0,(void*)gtoset,2,"DG"},
 {"Str",0,(void*)Str,2,"s*"},
+{"Strchr",18,(void*)Str_char,2,"G"},
 {"Strexpand",0,(void*)Strexpand,2,"s*"},
 {"Strtex",0,(void*)Strtex,2,"s*"},
 {"Vec",0,(void*)gtovec,2,"DG"},