use mrb_str_cat_lit for literals

src/codegen.c

@@ -1915,7 +1915,7 @@ codegen(codegen_scope *s, node *tree, int val)
       mrb_value fix = mrb_fixnum_value((intptr_t)tree);
       mrb_value str = mrb_str_buf_new(mrb, 4);
 
-      mrb_str_buf_cat(mrb, str, "$", 1);
+      mrb_str_cat_lit(mrb, str, "$");
       mrb_str_buf_append(mrb, str, mrb_fixnum_to_str(mrb, fix, 10));
       sym = new_sym(s, mrb_intern_str(mrb, str));
       genop(s, MKOP_ABx(OP_GETGLOBAL, cursp(), sym));

src/hash.c

@@ -676,14 +676,14 @@ inspect_hash(mrb_state *mrb, mrb_value hash, int recur)
 
       str2 = mrb_inspect(mrb, kh_key(h,k));
       mrb_str_append(mrb, str, str2);
-      mrb_str_buf_cat(mrb, str, "=>", 2);
+      mrb_str_cat_lit(mrb, str, "=>");
       str2 = mrb_inspect(mrb, kh_value(h,k));
       mrb_str_append(mrb, str, str2);
 
       mrb_gc_arena_restore(mrb, ai);
     }
   }
-  mrb_str_buf_cat(mrb, str, "}", 1);
+  mrb_str_cat_lit(mrb, str, "}");
 
   return str;
 }

src/object.c

@@ -440,11 +440,11 @@ mrb_any_to_s(mrb_state *mrb, mrb_value obj)
   mrb_value str = mrb_str_buf_new(mrb, 20);
   const char *cname = mrb_obj_classname(mrb, obj);
 
-  mrb_str_buf_cat(mrb, str, "#<", 2);
+  mrb_str_cat_lit(mrb, str, "#<");
   mrb_str_cat_cstr(mrb, str, cname);
   mrb_str_cat_lit(mrb, str, ":");
   mrb_str_concat(mrb, str, mrb_ptr_to_str(mrb, mrb_cptr(obj)));
-  mrb_str_buf_cat(mrb, str, ">", 1);
+  mrb_str_cat_lit(mrb, str, ">");
 
   return str;
 }

src/string.c

@@ -2522,7 +2522,7 @@ mrb_str_inspect(mrb_state *mrb, mrb_value str)
         continue;
       }
     }
-    mrb_str_buf_cat(mrb, result, "\"", 1);
+    mrb_str_cat_lit(mrb, result, "\"");
 
     return result;
 }

src/variable.c

@@ -596,7 +596,7 @@ mrb_obj_iv_inspect(mrb_state *mrb, struct RObject *obj)
     const char *cn = mrb_obj_classname(mrb, mrb_obj_value(obj));
     mrb_value str = mrb_str_buf_new(mrb, 30);
 
-    mrb_str_buf_cat(mrb, str, "-<", 2);
+    mrb_str_cat_lit(mrb, str, "-<");
     mrb_str_cat_cstr(mrb, str, cn);
     mrb_str_cat_lit(mrb, str, ":");
     mrb_str_concat(mrb, str, mrb_ptr_to_str(mrb, obj));