Use mrb_str_new() instead of mrb_str_new2() as possible.

src/array.c

@@ -887,7 +887,7 @@ inspect_ary(mrb_state *mrb, mrb_value ary, mrb_value list)
   /* check recursive */
   for(i=0; i<RARRAY_LEN(list); i++) {
     if (mrb_obj_equal(mrb, ary, RARRAY_PTR(list)[i])) {
-      return mrb_str_new2(mrb, "[...]");
+      return mrb_str_new(mrb, "[...]", 5);
     }
   }
 
@@ -929,7 +929,7 @@ inspect_ary(mrb_state *mrb, mrb_value ary, mrb_value list)
 static mrb_value
 mrb_ary_inspect(mrb_state *mrb, mrb_value ary)
 {
-  if (RARRAY_LEN(ary) == 0) return mrb_str_new2(mrb, "[]");
+  if (RARRAY_LEN(ary) == 0) return mrb_str_new(mrb, "[]", 2);
   #if 0 /* THREAD */
     return mrb_exec_recursive(inspect_ary_r, ary, 0);
   #else

src/numeric.c

@@ -15,6 +15,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <stdio.h>
+#include <assert.h>
 
 #if defined(__FreeBSD__) && __FreeBSD__ < 4
 #include <floatingpoint.h>
@@ -186,15 +187,21 @@ static mrb_value
 flo_to_s(mrb_state *mrb, mrb_value flt)
 {
   char buf[32];
+  int n;
   mrb_float value = mrb_float(flt);
 
-  if (isinf(value))
-    return mrb_str_new2(mrb, value < 0 ? "-inf" : "inf");
-  else if(isnan(value))
-    return mrb_str_new2(mrb, "NaN");
-
-  sprintf(buf, "%.14g", value);
-  return mrb_str_new2(mrb, buf);
+  if (isinf(value)) {
+    static const char s[2][5] = { "-inf", "inf" };
+    static const int n[] = { 4, 3 };
+    int idx;
+    idx = (value < 0) ? 0 : 1;
+    return mrb_str_new(mrb, s[idx], n[idx]);
+  } else if(isnan(value))
+    return mrb_str_new(mrb, "NaN", 3);
+
+  n = sprintf(buf, "%.14g", value);
+  assert(n >= 0);
+  return mrb_str_new(mrb, buf, n);
 }
 
 /* 15.2.9.3.2  */
@@ -1158,7 +1165,7 @@ mrb_fix2str(mrb_state *mrb, mrb_value x, int base)
     mrb_raise(mrb, E_ARGUMENT_ERROR, "invalid radix %d", base);
   }
   if (val == 0) {
-    return mrb_str_new2(mrb, "0");
+    return mrb_str_new(mrb, "0", 1);
   }
   if (val < 0) {
     val = -val;

src/range.c

@@ -343,7 +343,12 @@ inspect_range(mrb_state *mrb, mrb_value range, mrb_value dummy, int recur)
   struct RRange *r = mrb_range_ptr(range);
 
   if (recur) {
-    return mrb_str_new2(mrb, r->excl ? "(... ... ...)" : "(... .. ...)");
+    static const char s[2][14] = { "(... ... ...)", "(... .. ...)" };
+    static const int n[] = { 13, 12 };
+    int idx;
+
+    idx = (r->excl) ? 0 : 1;
+    return mrb_str_new(mrb, s[idx], n[idx]);
   }
   str  = mrb_inspect(mrb, r->edges->beg);
   str2 = mrb_inspect(mrb, r->edges->end);

src/sprintf.c

@@ -89,7 +89,7 @@ mrb_fix2binstr(mrb_state *mrb, mrb_value x, int base)
     val &= 0x3ff;
 
   if (val == 0) {
-    return mrb_str_new2(mrb, "0");
+    return mrb_str_new(mrb, "0", 1);
   }
   *--b = '\0';
   do {

src/string.c

@@ -21,6 +21,7 @@
 #include "regex.h"
 #include "st.h"
 #endif //ENABLE_REGEXP
+#include <assert.h>
 
 const char mrb_digitmap[] = "0123456789abcdefghijklmnopqrstuvwxyz";
 
@@ -220,7 +221,9 @@ mrb_str_buf_cat(mrb_state *mrb, mrb_value str, const char *ptr, int len)
 mrb_value
 mrb_str_new(mrb_state *mrb, const char *p, int len)
 {
-  struct RString *s = str_new(mrb, p, len);
+  struct RString *s;
+  assert(!(!p && len));
+  s = str_new(mrb, p, len);
   return mrb_obj_value(s);
 }
 
@@ -1969,7 +1972,7 @@ scan_once(mrb_state *mrb, mrb_value str, mrb_value pat, mrb_int *start)
     if (regs->num_regs == 1) {
       return mrb_reg_nth_match(mrb, 0, match);
     }
-    result = mrb_ary_new_capa(mrb, regs->num_regs);//mrb_ary_new2(regs->num_regs);
+    result = mrb_ary_new_capa(mrb, regs->num_regs);
     for (i=1; i < regs->num_regs; i++) {
       mrb_ary_push(mrb, result, mrb_reg_nth_match(mrb, i, match));
     }

src/struct.c

@@ -93,7 +93,7 @@ mrb_struct_s_members_m(mrb_state *mrb, mrb_value klass)
     mrb_value *p, *pend;
 
     members = mrb_struct_s_members(mrb, klass);
-    ary = mrb_ary_new_capa(mrb, RARRAY_LEN(members));//mrb_ary_new2(RARRAY_LEN(members));
+    ary = mrb_ary_new_capa(mrb, RARRAY_LEN(members));
     p = RARRAY_PTR(members); pend = p + RARRAY_LEN(members);
     while (p < pend) {
       mrb_ary_push(mrb, ary, *p);
@@ -493,7 +493,7 @@ static mrb_value
 inspect_struct(mrb_state *mrb, mrb_value s, mrb_value dummy, int recur)
 {
     const char *cn = mrb_class_name(mrb, mrb_obj_class(mrb, s));
-    mrb_value members, str = mrb_str_new2(mrb, "#<struct ");
+    mrb_value members, str = mrb_str_new(mrb, "#<struct ", 9);
     mrb_value *ptr, *ptr_members;
     long i, len;