Merge pull request #3757 from christopheraue/module_const_get_class_path

Extended Module#const_get to support class paths

include/mruby/string.h

@@ -84,6 +84,13 @@ MRB_API mrb_int mrb_str_strlen(mrb_state*, struct RString*);
 
 void mrb_gc_free_str(mrb_state*, struct RString*);
 MRB_API void mrb_str_modify(mrb_state*, struct RString*);
+
+/*
+ * Finds the index of a substring in a string
+ */
+MRB_API mrb_int mrb_str_index(mrb_state*, mrb_value, const char*, mrb_int, mrb_int);
+#define mrb_str_index_lit(mrb, str, lit, off) mrb_str_index(mrb, str, lit, mrb_strlen_lit(lit), off);
+
 /*
  * Appends self to other. Returns self as a concatnated string.
  *

src/class.c

@@ -2160,14 +2160,44 @@ mrb_mod_const_defined(mrb_state *mrb, mrb_value mod)
   return const_defined(mrb, mod, id, inherit);
 }
 
+static mrb_value
+mrb_const_get_sym(mrb_state *mrb, mrb_value mod, mrb_sym id)
+{
+  check_const_name_sym(mrb, id);
+  return mrb_const_get(mrb, mod, id);
+}
+
 static mrb_value
 mrb_mod_const_get(mrb_state *mrb, mrb_value mod)
 {
+  mrb_value path;
   mrb_sym id;
+  char *ptr;
+  mrb_int off, end, len;
 
-  mrb_get_args(mrb, "n", &id);
-  check_const_name_sym(mrb, id);
-  return mrb_const_get(mrb, mod, id);
+  mrb_get_args(mrb, "o", &path);
+
+  if (mrb_symbol_p(path)) {
+    /* const get with symbol */
+    id = mrb_symbol(path);
+    return mrb_const_get_sym(mrb, mod, id);
+  }
+
+  /* const get with class path string */
+  path = mrb_string_type(mrb, path);
+  ptr = RSTRING_PTR(path);
+  len = RSTRING_LEN(path);
+  off = 0;
+
+  while (off < len) {
+    end = mrb_str_index_lit(mrb, path, "::", off);
+    end = (end == -1) ? len : end;
+    id = mrb_intern(mrb, ptr+off, end-off);
+    mod = mrb_const_get_sym(mrb, mod, id);
+    off = (end == len) ? end : end+2;
+  }
+
+  return mod;
 }
 
 static mrb_value

src/string.c

@@ -478,15 +478,14 @@ str_substr(mrb_state *mrb, mrb_value str, mrb_int beg, mrb_int len)
   return str_subseq(mrb, str, beg, len);
 }
 
-static mrb_int
-str_index(mrb_state *mrb, mrb_value str, mrb_value sub, mrb_int offset)
+MRB_API mrb_int
+mrb_str_index(mrb_state *mrb, mrb_value str, const char *sptr, mrb_int slen, mrb_int offset)
 {
   mrb_int pos;
-  char *s, *sptr;
-  mrb_int len, slen;
+  char *s;
+  mrb_int len;
 
   len = RSTRING_LEN(str);
-  slen = RSTRING_LEN(sub);
   if (offset < 0) {
     offset += len;
     if (offset < 0) return -1;
@@ -498,14 +497,24 @@ str_index(mrb_state *mrb, mrb_value str, mrb_value sub, mrb_int offset)
   }
   if (slen == 0) return offset;
   /* need proceed one character at a time */
-  sptr = RSTRING_PTR(sub);
-  slen = RSTRING_LEN(sub);
   len = RSTRING_LEN(str) - offset;
   pos = mrb_memsearch(sptr, slen, s, len);
   if (pos < 0) return pos;
   return pos + offset;
 }
 
+static mrb_int
+str_index_str(mrb_state *mrb, mrb_value str, mrb_value str2, mrb_int offset)
+{
+  const char *ptr;
+  mrb_int len;
+
+  ptr = RSTRING_PTR(str2);
+  len = RSTRING_LEN(str2);
+
+  return mrb_str_index(mrb, str, ptr, len, offset);
+}
+
 static void
 check_frozen(mrb_state *mrb, struct RString *s)
 {
@@ -1096,7 +1105,7 @@ num_index:
       return str;
 
     case MRB_TT_STRING:
-      if (str_index(mrb, str, indx, 0) != -1)
+      if (str_index_str(mrb, str, indx, 0) != -1)
         return mrb_str_dup(mrb, indx);
       return mrb_nil_value();
 
@@ -1563,7 +1572,7 @@ mrb_str_include(mrb_state *mrb, mrb_value self)
   mrb_value str2;
 
   mrb_get_args(mrb, "S", &str2);
-  if (str_index(mrb, self, str2, 0) < 0)
+  if (str_index_str(mrb, self, str2, 0) < 0)
     return mrb_bool_value(FALSE);
   return mrb_bool_value(TRUE);
 }
@@ -1590,7 +1599,7 @@ mrb_str_include(mrb_state *mrb, mrb_value self)
  *     "hello".index(/[aeiou]/, -3)   #=> 4
  */
 static mrb_value
-mrb_str_index(mrb_state *mrb, mrb_value str)
+mrb_str_index_m(mrb_state *mrb, mrb_value str)
 {
   mrb_value *argv;
   mrb_int argc;
@@ -1631,7 +1640,7 @@ mrb_str_index(mrb_state *mrb, mrb_value str)
     }
     /* fall through */
     case MRB_TT_STRING:
-      pos = str_index(mrb, str, sub, pos);
+      pos = str_index_str(mrb, str, sub, pos);
       break;
   }
 
@@ -2752,7 +2761,7 @@ mrb_init_string(mrb_state *mrb)
 
   mrb_define_method(mrb, s, "hash",            mrb_str_hash_m,          MRB_ARGS_NONE()); /* 15.2.10.5.20 */
   mrb_define_method(mrb, s, "include?",        mrb_str_include,         MRB_ARGS_REQ(1)); /* 15.2.10.5.21 */
-  mrb_define_method(mrb, s, "index",           mrb_str_index,           MRB_ARGS_ANY());  /* 15.2.10.5.22 */
+  mrb_define_method(mrb, s, "index",           mrb_str_index_m,         MRB_ARGS_ANY());  /* 15.2.10.5.22 */
   mrb_define_method(mrb, s, "initialize",      mrb_str_init,            MRB_ARGS_REQ(1)); /* 15.2.10.5.23 */
   mrb_define_method(mrb, s, "initialize_copy", mrb_str_replace,         MRB_ARGS_REQ(1)); /* 15.2.10.5.24 */
   mrb_define_method(mrb, s, "intern",          mrb_str_intern,          MRB_ARGS_NONE()); /* 15.2.10.5.25 */

test/t/module.rb

@@ -268,6 +268,12 @@ assert('Module#const_get', '15.2.2.4.21') do
   end
 
   assert_equal 42, Test4ConstGet.const_get(:Const4Test4ConstGet)
+  assert_equal 42, Test4ConstGet.const_get("Const4Test4ConstGet")
+  assert_equal 42, Object.const_get("Test4ConstGet::Const4Test4ConstGet")
+
+  assert_raise(TypeError){ Test4ConstGet.const_get(123) }
+  assert_raise(NameError){ Test4ConstGet.const_get(:I_DO_NOT_EXIST) }
+  assert_raise(NameError){ Test4ConstGet.const_get("I_DO_NOT_EXIST::ME_NEITHER") }
 end
 
 assert('Module#const_missing', '15.2.2.4.22') do
@@ -280,7 +286,7 @@ assert('Module#const_missing', '15.2.2.4.22') do
   assert_equal 42, Test4ConstMissing.const_get(:ConstDoesntExist)
 end
 
-assert('Module#const_get', '15.2.2.4.23') do
+assert('Module#const_set', '15.2.2.4.23') do
   module Test4ConstSet
     Const4Test4ConstSet = 42
   end